JP4064986B2 - Method for selecting measurement points for optical output wavelength characteristics, optical output power characteristics, and RF amplitude characteristics - Google Patents

Description

  The present invention provides a direct modulation type optical communication light source unit that sets and controls an optical output wavelength, optical output power, and RF amplitude to specified values, and an optical output wavelength in the direct modulation type optical communication light source unit, The present invention relates to a method of selecting measurement points of light output wavelength characteristics, light output power characteristics, and RF amplitude characteristics of a light emitting element used for setting and controlling light output power and RF amplitude.

  In recent years, broadbandization of the Internet connection environment has progressed rapidly. Along with this, it has become necessary to further increase the transmission capacity of the network from the core system to the entire access / metro system. For this reason, development of large-capacity networks using optical communication technology has been actively conducted.

  In the optical communication light source unit, a light emitting element such as a laser diode (LD) is used to convert an electrical signal into an optical signal. At that time, in order to ensure normal optical communication, the light output wavelength and the light output power of each light emitting element constituting the light source unit are values determined according to the determined light wavelength arrangement and the loss of the optical transmission path, respectively. It is necessary to control to be held at those values. The light output wavelength and light output power of each light-emitting element depend on the drive current and element temperature, and are uniquely determined in the normal operating range.

  However, when the light emitting element is continuously used for a long time, the optical output power fluctuates due to secular change or the like, and means for automatically controlling the optical output power in accordance with the fluctuation of the optical output power (automatic power control circuit: APC) As a result, the drive current of each light emitting element also fluctuates so that the optical output power is maintained at a predetermined value. This causes the light output wavelength of each light emitting element to fluctuate outside the allowable range of the predetermined light wavelength arrangement.

  In the prior art, by combining a means for automatically controlling the element temperature, a means for automatically controlling the optical output power, and a means for automatically controlling the light output wavelength (wavelength locker), the light output wavelength is used. And setting and controlling the optical output power to a predetermined value.

  However, this wavelength locker is very expensive and requires very complicated settings and control, and it is a major obstacle in adapting to access and metro systems where low cost and simplicity are essential. It was.

  An example of a method for setting the optical output wavelength and optical output power of a light emitting element such as an LD according to the prior art is described in Non-Patent Document 1. The outline will be described below.

  FIG. 1 shows a configuration example of a light source unit for optical communication according to the prior art.

  The light source for optical communication includes a light emitting element 11, a means 12 for automatically controlling the light output power of the light output a 1 from the light emitting element 11 to be kept at a given target value, and an element temperature of the light emitting element 11. Means 13 for automatically controlling to keep the given target value, means 14 for branching the light output from the light emitting element 11, and keeping the light output wavelength of the branched light output b1 at the given target value. It comprises automatic control means (wavelength locker) 15. In this light source unit, the light output wavelength and light output power of the light emitting element 11 are set as follows.

  In the wavelength locker 15, the photocurrent generated by the detection of the optical output periodically changes with respect to the optical output wavelength as shown in FIG. In the prior art, the optical output wavelength is set using this property.

  Specifically, first, the device temperature is roughly adjusted as shown in FIG. 2 (a) by using means 13 for automatically controlling the device temperature so as to keep it at a given target value. The optical output wavelength is driven into a pull-in range corresponding to a separately specified optical output wavelength of the wavelength locker 15 shown in b). Next, the means 12 for automatically controlling the optical output power to be kept at the given target value is operated simultaneously, and the optical output power is separately designated while keeping the optical output wavelength within the pull-in range. Set to. Finally, in a state where the control target value of the means 12 for automatically controlling the optical output power to be kept at the given target value is fixed to the designated value, the wavelength locker 15 and the element temperature are set to the given target value. The means 13 for automatically controlling to keep is operated simultaneously.

  At this time, the light output wavelength is precisely adjusted to the designated value by finely adjusting the photocurrent generated in the wavelength locker 15 to a value corresponding to the separately designated light output wavelength.

  Non-patent document 2 describes an example of a method for controlling the optical output wavelength and optical output power of a light emitting element such as an LD according to the prior art. The light output wavelength and light output power of the light emitting element 11 are controlled as follows.

  In the wavelength locker 15, the photocurrent generated by the detection of the optical output periodically changes with respect to the optical output wavelength as shown in FIG. 2 (b). Therefore, this property is used to control the optical output wavelength. I do.

  Specifically, in the state where the control target value of the means 12 for automatically controlling the optical output power to be maintained at the given target value is fixed to the specified value, the wavelength locker 15 and the target given the element temperature. The means 13 for automatically controlling to keep the value is operated simultaneously. Thereby, when the light output power of the light emitting element 11 fluctuates, the means 12 for automatically controlling the light output power to maintain the given target value operates, so that the light output power becomes the control target value. The drive current of the light emitting element 11 is changed. This change in driving current changes the light output wavelength of the light emitting element 11 and the element temperature. As a result, the wavelength locker 15 and the means 13 for automatically controlling to keep the element temperature at the given target value operate to return the optical output wavelength to the specified value, and at the same time, the driving current when the optical output power fluctuates. Control is performed so as to maintain the element temperature in accordance with.

As described above, in the prior art, since the setting and control of the light output wavelength and light output power of the light emitting element 11 are performed in a plurality of stages, the wavelength locker is very complicated and very expensive. 15 was indispensable.
"PowerSource (TM) Tunable High Power CW Laser Module with Integrated Wavelength Monitoring", [online], Avanex Inc., [Search March 7, 2005], Internet <URL: http://www.avanex.com/ Products / datasheets / Transmission / PwrSource.1935TLI.C.pdf> Takagi et al. "DFB laser module with built-in 25GHz interval wavelength monitor" 2002 Proceedings of the IEICE General Conference C-4-44, 2002, page 349 A. Zadok, et al. "Spectral shift and broadening of DFB lasers under direct modulation", IEEE Photon. Technol. Lett., Vol. 10, No. 12, pp. 1709-1711, 1998 ITU-T recommendation, G959.1, 2001

  As described above, in the prior art, the setting and control of the light output wavelength and the light output power of the light emitting element are performed in a plurality of stages, so a very complicated and very expensive wavelength locker is indispensable. Met. However, these points have a problem that they become a great barrier in application to an access / metro system where low cost and simplicity are essential.

  Such a problem of the prior art eliminates the need for the very complicated setting and control and the very expensive optical component (wavelength locker) that the inventors have already invented and applied for, and the optical output wavelength and the wavelength can be simply and inexpensively. This can be solved by a light source for optical communication configured to set and control both optical output powers. The contents of the inventions already filed (Japanese Patent Application Nos. 2004-230458 and 2004-26196: hereinafter referred to as the prior application 1 and the prior application 2, respectively) will be described.

  The light source unit for optical communication for setting the optical output wavelength and the optical output power is described in the prior application 1. In the prior application 1, the following properties regarding the light output wavelength and light output power of a light emitting element such as an LD are used. As shown in FIG. 3A, the dependency of the light output wavelength of the light emitting element on the driving current and the element temperature is monotonously decreased with respect to both the driving current and the element temperature within the normal operating range. In addition, as shown in FIG. 3B, the dependence of the light output power of the light emitting element on the driving current and the element temperature increases monotonously with respect to the driving current and monotonically with respect to the element temperature within the normal operating range. Decrease.

  Therefore, when the optical output wavelength to be operated within the normal operating range is designated, the equivalent optical output wavelength line that satisfies this operating condition is orthogonally projected onto the (driving current-element temperature) coordinate plane as shown in FIG. As shown by a thick solid line, a single open curve that falls to the right (monotonically decreases) within that range. Similarly, when the optical output power to be operated within the normal operation range is designated, the iso-optical output power line that satisfies this operation condition is orthogonally projected onto the (drive current-element temperature) coordinate plane as shown in FIG. As shown by a thick broken line, a single open curve that rises to the right (monotonically increases) within the range. Therefore, as shown in FIG. 3C, these two open curves intersect at one point within the normal operating range. Therefore, the coordinate value (drive current, element temperature) of this intersection is uniquely determined, and the value is the target value of the drive current and element temperature at which both the optical output wavelength and the optical output power are specified. .

As shown in FIG. 5, the configuration example of the light source unit for optical communication according to the present invention is composed of a light emitting element such as an LD, and generates a light output 21 and a driving current or light of the light emitting element constituting the means 21. A means 22 for automatically controlling the output power to be kept at a given target value, a means 23 for automatically controlling the element temperature of the light emitting elements constituting the means 21 to be kept at a given target value, and means 21 in the light-emitting element in the light-emitting element, which constitutes at least one value of the optical output wavelength for the drive current and device temperature, Oh Rui least one parameter value for determining the these three relationships, and means 21 constituting the drive at least one value of the optical output power for current and device temperature, Oh Rui and means 24 for storing at least one parameter value for determining the these three relationships, means 24 The relationship between the drive current, the element temperature, and the light output wavelength of the light emitting element, the drive current of the light emitting element, the element temperature, and the light output power, which are determined by at least one value for the light emitting element constituting the stored means 21. Therefore, the light output wavelength and the light output power of the light emitting element are configured by means 25 for determining the drive current or the light output power and the element temperature at which both values are specified separately. The symbol a2 is the optical output from the means 21, b2 is the designated optical output wavelength and optical output power, c2 is the drive current or optical output power determined by the means 25, and d2 is the element temperature determined by the means 25. It is.

  The setting of the optical output wavelength and the optical output power is performed as follows.

  In the means 25, at least one value stored in the means 24 is used to calculate a parameter value that determines the relationship among the drive current, the element temperature, and the optical output power for the light emitting element constituting the means 21. Next, based on the designated light output wavelength and light output power b2, using the calculated parameter values, the light output wavelength and light output power of the light emitting elements constituting the means 21 are simultaneously designated values. The drive current or optical output power c2 and the element temperature d2 are calculated. The calculated drive current or optical output power c2 is set as a target value in the means 22, and the calculated element temperature d2 is set as a target value in the means 23. In this way, the optical output wavelength and optical output power of the optical output a2 from the means 21 can be set to specified values.

  On the other hand, a light source unit for optical communication that controls the optical output wavelength and the optical output power to predetermined values is described in the prior application 2. Prior application 2 utilizes the following properties relating to the light output wavelength and light output power of the light emitting element. FIGS. 4A and 4B show the dependency of the light output wavelength on the drive current and the device temperature and the dependency of the light output power on the drive current and the device temperature, respectively, when the light output power of the light emitting device varies. The fact that these are “monotonic” is the same as that before the fluctuation of the optical output power, and the dependency of the optical output power on the drive current and the element temperature differs only in the part where the parallel movement occurs according to the increase or decrease of the drive current.

  As a result, as shown by a thick alternate long and short dash line in FIG. 4C, the equivalent optical output power line that becomes the specified optical output power is orthogonally projected onto the (drive current-element temperature) coordinate plane. To move in parallel. This parallel movement intersects with the equal optical output wavelength line at one point in the normal operating range, and therefore, as before the fluctuation of the optical output power, both the optical output wavelength and the optical output power are specified values. The target values of the drive current and the element temperature are uniquely determined.

  As shown in FIG. 6, the configuration example of the light source unit for optical communication according to the present invention is different from the light source unit for optical communication in FIG. Monitoring, comparing and determining whether or not it is within a separately specified allowable variation range, and if not within the allowable variation range, the driving current of the light emitting element determined by at least one value stored in the means 24 and Based on the relationship between the element temperature and the light output power, the means 26 for predicting the relationship between the drive current, the element temperature, and the light output power when the drive current of the light emitting element varies, and at least one value stored in the means 24 The determined relationship between the drive current, the element temperature, and the light output wavelength of the light emitting element constituting the means 21, and the drive current, the element temperature, and the light when the drive current of the light emitting element constituting the means 21 predicted by the means 26 varies. With output power And a means 27 for predicting the latest drive current or optical output power and the latest element temperature at which both the light output wavelength and the light output power when the drive current of the light emitting element fluctuates are separately specified values. The prepared point is different. Reference symbol e2 is a drive current of the light emitting element constituting the means 21, f2 is an allowable fluctuation range of the drive current specified separately, and g2 is a drive current fluctuation of the light emitting element constituting the means 21 predicted by the means 26. The parameter value that determines the relationship among the drive current, element temperature, and optical output power, h2 is the latest drive current or optical output power determined by means 27, and j2 is the latest element temperature determined by means 27.

  Adjustment to the predetermined values of the optical output wavelength and the optical output power is performed as follows.

  First, in the means 27, using at least one value input from the means 24, a parameter value that determines the relationship among the drive current, the element temperature, and the light output wavelength for the light emitting element constituting the means 21 is calculated. In the means 26, using at least one value input from the means 24, a parameter value that determines the relationship among the drive current, the element temperature, and the optical output power before the drive current fluctuation for the light emitting element constituting the means 21 is obtained. calculate. Next, in the means 26, the drive current e2 of the light emitting element constituting the means 21 is monitored, and it is compared and determined whether or not this is within the allowable fluctuation range f2 of the drive current specified separately.

  When the drive current e2 is not within the allowable fluctuation range f2, the means 26 uses the calculated parameter value to drive the drive current, the element temperature, and the optical output for the light-emitting element constituting the means 21 when the drive current fluctuates. A parameter value g2 that determines the relationship with power is predicted, calculated, and output to the means 27. Based on the separately specified light output wavelength and light output power, the means 27 uses the calculated parameter value and the parameter value g2 input from the means 26 to change the drive current of the light emitting element constituting the means 21. The latest drive current or optical output power h2 and the latest element temperature j2 at which the optical output wavelength and the optical output power at are simultaneously specified values b2 are calculated.

  The drive current or optical output power h2 calculated in the above process is set to the means 22 as a new target value when the drive current fluctuates, and the calculated element temperature j2 is similarly set to the means 23 as a new target value. To do. In this way, even when the drive current fluctuates, it is possible to automatically control so that both the light output wavelength and the light output power of the light output a2 from the means 21 become the separately designated value b2.

  As described above, in the optical communication light source units of the prior application 1 and the prior application 2, the “monotonic” characteristics regarding the light output wavelength and the light output power of the light emitting element are obtained using the values stored in the means 24. It is a feature to estimate.

  By the way, in the light source part for optical communication as described above, the estimation error of the optical output wavelength and the optical output power is stored in the means 24, and the measurement points (drive current, optical output power characteristic) of the light output wavelength characteristic and the optical output power characteristic of the light emitting element are stored. Depending on how the element temperature is selected, the light output wavelength characteristics and the light output power characteristics differ for each light emitting element, and therefore the operating range of the drive current and the element temperature varies for each light emitting element.

  Regarding the selection of the measurement points of the optical output wavelength characteristics and the optical output power characteristics in the operating ranges of the driving current and the element temperature which are different for each light emitting element, the inventors have already invented and filed the application of the light emitting element. This can be solved by a method of selecting measurement points for the optical output wavelength characteristic and the optical output power characteristic that reduce the estimation error of the optical output wavelength and the optical output power within the specified drive current and element temperature range. The contents of the invention of the already filed application (Japanese Patent Application No. 2005-075245: hereinafter referred to as prior application 3) will be described below.

  In prior application 3, when considering the light output wavelength characteristics of light emitting elements such as LDs, the second order terms of drive current and element temperature are taken into consideration in a three-dimensional space with drive current, element temperature and light output wavelength as coordinate axes. (The optical output wavelength characteristic is expressed by a quadratic function of the driving current and the element temperature.) Similarly, when considering the optical output power characteristic of the light emitting element, the driving current, the element temperature, and the optical output power are three-dimensional with respect to the coordinate axes. In the space, consideration is given up to a quadratic term of the drive current and the element temperature (the optical output power characteristic is expressed by a function of the drive current and the element temperature). In actual setting and control of the optical output wavelength and optical output power, the optical output wavelength characteristic of the light emitting element is approximated by a plane (linear function of drive current and element temperature), and similarly the optical output power characteristic of the light emitting element. Is approximated by a plane (linear function of drive current and element temperature). When the light output wavelength characteristic of the light emitting element is approximated by a plane, if there are three measurement points for each, a coefficient of a linear function representing the light output wavelength characteristic can be calculated.

  A method for selecting a measurement point in consideration of the light output wavelength characteristic of the light emitting element will be described with reference to FIG.

FIG. 7A shows the drive current dependence of the optical output wavelength when the element temperature is fixed at a certain value within the operating range. Symbols i ₁ and i ₂ represent the minimum value and the maximum value of the drive current i in the operation range. The actual optical output wavelength characteristic is represented by a quadratic function of the drive current i, and the approximate line is represented by a linear function of the drive current i. As described above, the driving current is monotonously decreased.

Here, the operating range (i ₁ ≦ i ≦ i ₂ ) of the driving current i is internally divided by p: 1-p and 1-p: p (p is the ratio coordinate of the internal dividing point of the operating range of the driving current i) And a real number satisfying 0 <p <1). When the approximate error of the optical output wavelength is represented by δλ ₀ , from the figure, δλ ₀ is the maximum at i = (i ₁ + i ₂ ) / 2 and is the minimum at i = i ₁ or i = i ₂ . FIG. 8 shows a plot of the approximate error ratio | δλ ₀ | _{i = i1 or i2} / | δλ ₀ | _{i = (i1 + i2) / 2} and its inverse as a function of the value of p. Show. Except for the value of p where the ratio of approximation errors is 1 (that is, the absolute value of the approximation error is equal to the absolute value of the minimum value), | δλ ₀ | _{i = i1 or i2} , | δλ ₀ | _{i = (i1 Since} either _{+ i2) / 2} increases rapidly, the approximation error in the operating range increases.

Therefore, by determining the value of p so that | δλ ₀ | _{i = i1 or i2} = | δλ ₀ | _{i = (i1 + i2) / 2} , the absolute values of the maximum value and the minimum value of the approximation error are obtained. It is considered that the approximation error in the operation range becomes small. Using this p, the drive currents i _s1 and i _s2 that internally divide the operation range by p: 1-p and 1-p: p may be used as the drive currents at the measurement points.

  The same applies to the element temperature dependency of the optical output wavelength (FIG. 7B). The above discussion can be similarly applied to the drive current and device temperature dependence of the optical output power.

As a result, as shown in FIG. 9, (i _s1 , T _s1 ) and (i _s1 , T _s2 ) are measurement points for determining the light output wavelength of the light emitting element and the drive current and element temperature dependence of the light output power. ), (I _s2 , T _s1 ), and (i _s2 , T _s2 ) can be determined. Actually, in order to determine the coefficient of the linear function in the three-dimensional space, any three of the four points may be selected as measurement points.

  As described above, according to the prior application 1 and the prior application 2, the light source unit for optical communication that sets and controls the optical output wavelength and the optical output power can be configured easily and inexpensively. In addition, according to the prior application 3, it is possible to select a measurement point at which these estimation errors are reduced when setting and controlling the optical output wavelength and the optical output power. Each configuration is characterized by estimating monotonous characteristics regarding the light output wavelength and light output power of the light emitting element.

  The light source for optical communication as described above is mainly assumed for external modulation, and the light output from the light emitting element is continuous light (CW light). When considering application to the access / metro system, a direct modulation type optical communication light source unit is required to reduce the number of parts and reduce the price. In the direct modulation type optical communication light source unit, an RF signal for direct modulation is superimposed on the drive current and applied to the light emitting element. In the signal light directly modulated by the RF signal, the optical output wavelength is shifted and the signal light spectrum is widened as compared with the time of CW (see Non-Patent Document 3). For this reason, when setting and controlling the optical output wavelength and optical output power wavelength of the direct modulation type optical communication light source unit, the relationship between the drive current, element temperature, and optical output wavelength during direct modulation, and during direct modulation. The relationship among the drive current, element temperature, and optical output power may be stored.

For signal light generated by the light source for optical communication, requirements for extinction ratio and eye mask are provided in order to ensure normal communication. Non-Patent Document 4 describes a rule for extinction ratio (8.2 dB or more) and an eye mask rule defined by each transmission speed and format. The extinction ratio of the signal light and the eye mask are determined by the relationship between the drive current applied to the light emitting element, the RF amplitude, and the element temperature. Therefore, in order to satisfy the above definition, in the optical communication light source unit, the RF amplitude is controlled by the automatic bias control circuit (ABC) so that the desired signal light extinction ratio and eye mask can be obtained with respect to the drive current and the element temperature. Controlled to a constant value.

However, as described above, the drive current fluctuates due to the aging of the light emitting element, or the target value of the drive current and the element temperature differs depending on the set value of the light output wavelength. In necessarily Tsu Naka can meet the extinction ratio and eye mask requirement.

FIG. 10 shows an eye pattern measurement example when the DFB-LD butterfly module is directly modulated at 2.5 Gbps. During the measurement, the RF amplitude and the element temperature were constant. When the drive current is smaller than the appropriate value (FIG. 10B), the RF amplitude becomes excessive with respect to the drive current, the signal light waveform is disturbed and the light emitting element may be destroyed (FIG. 10A). On the other hand, when the drive current is larger than the appropriate value, sufficient modulation by RF is not performed, and a sufficient eye opening that satisfies the desired extinction ratio and eye mask specification cannot be obtained (FIG. 10C). When the ratio of the RF amplitude to the drive current is controlled to be constant, there is no possibility of element destruction due to excessive RF, but the behavior when the RF amplitude is too small is the same.

Direct modulation optical communication that can set and control the optical output wavelength and optical output power, and satisfy the specified extinction ratio and eye mask specifications, within the operating range of the specified drive current and element temperature of the light emitting element The light source unit for use has not been studied so far.

In order to solve such problems, the object of the present invention is to set and control the optical output wavelength and the optical output power within a specified driving current and element temperature operating range of the light emitting element, and to achieve a predetermined extinction ratio. and definitive direct modulation type optical communication light source unit which satisfies the eye mask requirement, the optical output wavelength, and to provide a method of selecting the measuring points estimation error of the optical output power and RF amplitude is reduced.

In order to achieve the above object, a direct modulation type optical communication light source unit that sets and controls the optical output wavelength and optical output power and satisfies a predetermined extinction ratio and eye mask specification, and further, the direct modulation type A method of selecting measurement points for the optical output wavelength, optical output power, and RF amplitude stored in the optical communication light source unit will be described. Here, in addition to the light output wavelength and light output power of each light emitting element, the “monotonic” characteristics as shown in FIG. 11 are also estimated with respect to the RF amplitude during direct modulation that satisfies a predetermined extinction ratio and eye mask definition. It is a feature.

First, a direct modulation optical communication light source unit that sets an optical output wavelength and optical output power and satisfies a predetermined extinction ratio and eye mask specification will be described.

As information necessary for determining the dependency of the optical output wavelength on the driving current and the element temperature, at least one of the optical output wavelength with respect to the driving current and the element temperature during direct modulation satisfying a predetermined extinction ratio and eye mask specification value, Oh Rui least one parameter value for determining the these three relationships, also as information necessary to determine the dependence on drive current and device temperature of the light output power, predetermined extinction ratio and eye mask at least one value of the optical output power for the drive current and device temperature direct modulation time satisfying the provisions, Oh Rui least one parameter value for determining the these three relations, further the optical output wavelength and optical output power at least one value of the RF amplitude for the drive current and device temperature to give, Oh Rui determines these three relationships at least one path The meter value, a means for storing in advance, provided the direct modulation type optical communication light source unit.

The direct modulation type optical communication light source unit includes means for determining a drive current or optical output power, an element temperature, and an RF amplitude in which both the light output wavelength and the light output power of the light emitting element are separately specified values. Provide. Using this means, using at least one value stored in advance in the light source unit for optical communication, the drive current and element temperature of the optical output wavelength during direct modulation satisfying a predetermined extinction ratio and eye mask specification Find the parameter value that determines the dependency. Similarly, a parameter value that determines the drive current and element temperature dependence of the optical output power during direct modulation that satisfies a predetermined extinction ratio and eye mask definition is obtained using the at least one value. Using these parameter values, the coordinate values (drive current, element temperature) of the intersection described above are calculated.

Further, by using the at least one value, a driving current having an RF amplitude that gives an optical output wavelength and optical output power at the time of direct modulation satisfying a predetermined extinction ratio and an eye mask definition as shown in FIG. A parameter value that determines the element temperature dependency is obtained. Based on the calculated coordinate value (drive current, element temperature) and the RF amplitude at the coordinate value, the drive current or the optical output power at which both the light output wavelength and the light output power of the light emitting element are separately designated. Determine device temperature and RF amplitude.

  Means for automatically controlling the drive current or optical output power provided in the light source unit for direct modulation type optical communication, the drive current or optical output power determined as described above, the element temperature and the RF amplitude, and the element temperature automatically And a means for automatically controlling the RF amplitude are given as respective target values.

Next, a direct modulation type optical communication light source unit that adjusts and controls the optical output wavelength and optical output power and satisfies a predetermined extinction ratio and eye mask specification will be described.

Similar to the above, as information necessary for determining the dependency of the optical output wavelength on the driving current and the element temperature, the optical output with respect to the driving current and the element temperature at the time of direct modulation satisfying the predetermined extinction ratio and the eye mask specification. at least one value of the wavelength, Oh Rui least one parameter value for determining the these three relationships, also as information necessary to determine the dependence on drive current and device temperature of the light output power, predetermined at least one value of the optical output power for the drive current and device temperature direct modulation time satisfying the extinction ratio and eye mask requirement, Oh Rui least one parameter value for determining the these three relations, further the light output at least one value of the RF amplitude for the drive current and device temperature which gives the wavelength and optical output power, Oh Rui small to determine these three parties relationships Both the single parameter values, providing a means for storing in advance in the direct modulation type optical communication light source unit.

Further, in the light source unit for direct modulation type optical communication, the drive current of the light emitting element is monitored, and it is compared and determined whether or not it is within a separately specified allowable fluctuation range, and based on the comparison determination result, the light emitting element A means for predicting the dependence of the optical output power on the drive current and the element temperature during direct modulation that satisfies the predetermined extinction ratio and eye mask specification when the drive current fluctuates, and the dependence of the RF amplitude on the drive current and the element temperature Provide. As shown in FIG. 11B, the dependence on the driving current and the element temperature is predicted by using the “monotonic” property for the RF amplitude and performing parallel movement according to the increase and decrease of the driving current.

Further, in the light source unit for direct modulation type optical communication, both the light output wavelength and the light output power at the time of direct modulation satisfying a predetermined extinction ratio and eye mask specification when the driving current of the light emitting element fluctuates are separately designated. Means for determining the driving current and the element temperature are provided. Using this means, using at least one value stored in advance in the light source unit for direct modulation optical communication, the drive current of the optical output wavelength at the time of direct modulation that satisfies the predetermined extinction ratio and eye mask specification And a parameter value for determining the element temperature dependency.

Using this parameter value and the parameter value that determines the drive current and element temperature dependence of the optical output power at the time of direct modulation that satisfies the predetermined extinction ratio and eye mask specification when the drive current fluctuates calculated by the prediction means Then, the coordinate value (drive current, element temperature) of the intersection when the drive current fluctuates is calculated. A parameter value that determines the drive current and element temperature dependency of the RF amplitude at the time of direct modulation that satisfies the predetermined extinction ratio and eye mask specification when the drive current fluctuates calculated by the prediction means, and the calculated coordinate value (drive current) , Element temperature) and a new target value of the drive current, the element temperature, and the RF amplitude at which both the light output wavelength and the light output power of the light emitting element are separately specified values are determined. .

  The drive current, element temperature, and RF amplitude determined as described above are respectively set as new target values for means for automatically controlling the optical output power, element temperature, and RF amplitude provided in the light source unit for direct modulation type optical communication. By giving, the light output wavelength and light output power of the light emitting element are adjusted and controlled so as to be held at specified values.

  Finally, a method of selecting measurement points for the optical output wavelength, optical output power, and RF amplitude stored in the light source unit for direct modulation optical communication will be described.

When considering the light output wavelength characteristics at the time of direct modulation in which a light emitting element such as an LD satisfies a predetermined extinction ratio and eye mask specification, the drive current is measured in a three-dimensional space with the drive current, element temperature and light output wavelength as coordinate axes. And the second order term of the element temperature (the light output wavelength characteristic is expressed by a quadratic function of the drive current and the element temperature), and the light at the time of direct modulation in which the light emitting element satisfies the predetermined extinction ratio and the eye mask specification. When considering the output power characteristics, in the three-dimensional space with the drive current, element temperature, and optical output power as coordinate axes, the second term of the drive current and element temperature is taken into consideration (the optical output power characteristics are considered as the drive current and element temperature). Similarly, when considering the RF amplitude at the time of direct modulation in which the light emitting element satisfies the predetermined extinction ratio and the eye mask specification, the three-dimensional using the drive current, the element temperature, and the RF amplitude as coordinate axes. In space There are, considered up to the second order term of the drive current and device temperature (representative of the RF amplitude characteristics by a quadratic function of the drive current and device temperature.).

In addition, when the optical output wavelength, optical output power, and RF amplitude at the time of direct modulation satisfying a predetermined extinction ratio and eye mask specification are actually set and controlled, the light output wavelength characteristic of the light emitting element is set to a plane (drive current and element temperature) The light output power characteristic of the light emitting element is similarly approximated by a plane (linear function of driving current and element temperature), and the RF amplitude of the light emitting element is further approximated by a plane (driving current and element temperature). Approximated by a linear function).

  When approximating the light output wavelength characteristic of a light emitting element in a plane, if there are three measurement points for each, a coefficient of a linear function representing the light output wavelength characteristic can be calculated. , (Driving current-element temperature) Within the operating range on the coordinate plane, the difference between the actual optical output wavelength characteristic and the optical output wavelength characteristic approximated by plane becomes smaller. To the problem you choose. The same applies to the optical power characteristic and the RF amplitude characteristic of the light emitting element.

  First, selection of measurement points in consideration of the light output wavelength characteristics of the light emitting element will be described.

The actual optical output wavelength characteristic at the time of direct modulation that satisfies the predetermined extinction ratio and eye mask definition is represented by a quadratic function of the drive current i, and the approximate line is represented by a linear function of the drive current i. Here, as shown in FIG. 12A, the operating range (i ₁ ≦ i ≦ i ₂ ) of the drive current i is internally divided by p: 1−p and 1−p: p (p is the drive current i). Is a ratio coordinate of the inner dividing point of the operation range of the real number satisfying 0 <p <1). It expressed predetermined extinction ratio and the approximation error of the optical output wavelength of the direct modulation time satisfying the eye mask requirement in _{δλ 0, | δλ 0 | i} = i1 or i2 = | δλ 0 | i = (i1 + i2) / By determining the value of p to be ₂ , it is considered that the absolute value of the maximum value and the minimum value of the approximation error are equal, and the approximation error within the operating range is reduced. Using this p, the drive currents i _s1 and i _s2 that internally divide the operation range by p: 1-p and 1-p: p may be used as the drive currents at the measurement points.

Similarly, an actual optical output wavelength characteristic at the time of direct modulation that satisfies a predetermined extinction ratio and eye mask specification is represented by a quadratic function of the element temperature T, and an approximate line is represented by a linear function of the element temperature T. . The operating range of element temperature T (T ₁ ≦ T ≦ T ₂ ) is internally divided by q: 1-q and 1-q: q as shown in FIG. 12B (q is the operating range of element temperature T). The ratio coordinates of internal dividing points, which are real numbers satisfying 0 <q <1, and the absolute values of the maximum and minimum approximation errors are equal (| δλ ₀ | _{T = T1 or T2} = | δλ ₀ | _{T =} Determine the value of q _{(which is (T1 + T2) / 2} ). Using this q, element temperatures T _s1 and T _s2 that internally divide the operating range by q: 1-q and 1-q: q are set as element temperatures at the measurement points. As described above, in practice, the same value as p calculated above can be used as the value of q. The same applies to the optical output power characteristic (approximation error δP ₀ ) and the RF amplitude characteristic (approximation error δi _RF0 ) (FIGS. 13A and 13B).

As a result, the drive current and device temperature dependence of the light output wavelength of the light emitting device during direct modulation satisfying the predetermined extinction ratio and eye mask specification, and the drive current and device temperature dependence of the optical output power are determined. Four measurement points (i _s1 , T _s1 ), (i _s1 , T _s2 ), (i _s2 , T _s1 ), (i _s2 , T _s2 ) can be determined (FIG. 14). Actually, in order to determine the coefficient of the linear function in the three-dimensional space, any three of the four points may be selected as measurement points.

In this way, by setting, adjusting, and controlling the light output wavelength and light output power, the light output wavelength and light output power can be set and controlled in the operating range of the specified drive current and device temperature of the light emitting element. In addition, it is possible to realize an optical communication light source unit for direct modulation that satisfies a predetermined extinction ratio and eye mask definition. In addition, by selecting measurement points for determining the drive current and element temperature dependence of the light output wavelength of the light emitting element, and the drive current and element temperature dependence of the light output power of the light emitting element, light for direct modulation is selected. In the communication light source unit, the estimation error of the light output wavelength and the light output power can be reduced.

As described above, according to the present invention, in a direct modulation optical communication light source unit that does not require very complicated setting and control and a very expensive optical component (wavelength locker), a predetermined extinction ratio and While satisfying the eye mask regulations, it is possible to set and control both the light output wavelength and the light output power easily and inexpensively, and to reduce the estimation error of the light output wavelength and the light output power. Such a light source unit for optical communication can be sufficiently applied to an access / metro system that is essential to be inexpensive and simple.

  Embodiments of the present invention will be described below with reference to the drawings.

[Embodiment 1]
Figure 15 is a form of implementation of the present invention 1 (but not included in the scope of the appended claims.) Shows the structure of a.

  In the figure, reference numeral 1 is composed of a light emitting element such as an LD, and is a first means for generating light output, and 2 is a target value to which a drive current or light output power of the light emitting element constituting the first means 1 is given. The second means 3 for automatically controlling by feedback control or the like so as to keep at 3 is automatically controlled by feedback control or the like so as to keep the element temperature of the light emitting element constituting the first means 1 at a given target value. The third means 4 is a fourth means for automatically controlling the RF amplitude for direct modulation of the light emitting elements constituting the first means 1 by feedback control or the like so as to keep the given target value.

Further, with respect to the light emitting device constituting the first means 1 5, at least one value of the optical output wavelength for the drive current and device temperature direct modulation time satisfying the predetermined extinction ratio eye mask requirement, Oh Rui these 3 and at least one parameter value for determining the relationship between the user, at least one value of the optical output power for the drive current and device temperatures of direct modulation time satisfying the predetermined extinction ratio and eye mask requirement, Oh Rui these 3 at least one parameter value for determining the users of relationships, predetermined extinction ratio and at least one value of the RF amplitude for the drive current and device temperature direct modulation time satisfying the eye mask requirement, Oh Rui these three relationships And a fifth means for storing at least one parameter value for determining.

Further, 6 is determined by at least one value for the light emitting element stored in the fifth means 5, and the driving current, element temperature and light during direct modulation satisfying a predetermined extinction ratio and eye mask definition of the light emitting element. From the relationship between the output wavelength and the relationship between the drive current, the element temperature, and the optical output power at the time of direct modulation that satisfies the predetermined extinction ratio / eye mask specification of the light emitting element, the light output wavelength and light of the light emitting element The drive current or the optical output power and the element temperature at which both the output powers are separately specified values are determined, and at the time of the drive current fluctuation at the time of direct modulation that satisfies the predetermined extinction ratio and eye mask specification of the light emitting element This is a sixth means for determining the determined drive current or optical output power and the RF amplitude at the device temperature from the relationship between the drive current, the device temperature and the RF amplitude.

  The symbol a is the optical output from the first means 1, b is the designated optical output wavelength and optical output power, c is the drive current or optical output power determined by the sixth means 6, and d is the sixth. The RF amplitude determined by the means 6 is e, and the element temperature is determined by the sixth means 6.

  FIG. 16 shows an operation procedure of the present embodiment.

First, (1-1), the at least one value of the optical output wavelength for the drive current and device temperature direct modulation time satisfying the predetermined extinction ratio and eye mask requirement stored in the means 5 of the fifth, Oh Rui at least one parameter value for determining the these three relationships, at least one value of the optical output power for the drive current and device temperature direct modulation time satisfying the predetermined extinction ratio and eye mask requirement, Oh Rui these 3 and at least one parameter value for determining the relationship between the user, at least one value of the RF amplitude for a given extinction ratio and the drive current and device temperature of the direct modulation time satisfying the eye mask requirement, Oh Rui these three And at least one parameter value that determines the relationship between the first and second parameters is read out and output to the sixth means 6.

In (1-2), the sixth means 6 uses the at least one value input from the fifth means 5 to use a predetermined extinction ratio and eye mask definition for the light-emitting elements constituting the first means 1. The parameter value that determines the relationship among the drive current, the element temperature, and the optical output wavelength during direct modulation that satisfies the above is calculated.

In (1-3), the sixth means 6 uses the at least one value input from the fifth means 5 to use a predetermined extinction ratio and eye mask definition for the light-emitting elements constituting the first means 1. The parameter value that determines the relationship among the drive current, the element temperature, and the optical output power during direct modulation that satisfies the above is calculated.

Similarly, in (1-4), the sixth means 6 uses the at least one value input from the fifth means 5 to use a predetermined extinction ratio and an eye for the light emitting element constituting the first means 1. A parameter value that determines the relationship among the drive current, the element temperature, and the RF amplitude during direct modulation that satisfies the mask definition is calculated.

Next, in (1-5), the sixth means 6 uses the parameter values calculated in (1-2) and (1-3) based on the designated optical output wavelength and optical output power b. Calculating the driving current or the optical output power c and the element temperature e at which the light output wavelength and the light output power of the light emitting element at the time of direct modulation satisfying a predetermined extinction ratio and an eye mask specification are simultaneously designated, At the same time, the parameter value calculated in (1-4) is used to calculate the calculated / determined drive current or optical output power and the RF amplitude d at the element temperature.

  In (1-6), the drive current or optical output power c calculated in (1-5) is set as a target value in the second means 2, and the element temperature e calculated in (1-5) is set to the first value. The RF amplitude d calculated in (1-5) is set as a target value in the fourth means 4 while being set as a target value in the third means 3. In this way, the optical output wavelength and optical output power of the optical output a from the first means 1 can be set and controlled to specified values.

  The operation procedures (1-1) to (1-6) described above can be realized as follows, for example.

Here, the light output wavelength characteristic at the time of direct modulation that satisfies the predetermined extinction ratio and eye mask specification of the light emitting element is a plane (drive current and element in a three-dimensional space with the drive current, element temperature, and light output wavelength as coordinate axes. The light output power characteristic during direct modulation that is well expressed by the linear function of temperature and satisfies the predetermined extinction ratio and eye mask specification of the light emitting element is three-dimensional with the drive current, element temperature, and light output power as coordinate axes. The RF amplitude characteristics during direct modulation, which is well represented by a plane (linear function of drive current and element temperature) in space, and that satisfies the predetermined extinction ratio and eye mask definition, similarly represent the drive current, element temperature, and optical output wavelength. A case will be described in which a three-dimensional space having coordinate axes is well expressed by a plane (linear function of drive current and element temperature). The fifth means 5 will be described by taking as an example the case where the values of the light output wavelength, light output power and RF amplitude of the light emitting element with respect to the predetermined drive current and element temperature are stored.

  In (1-1), these values stored in the fifth means 5 are read out and input to the sixth means 6.

In (1-2), the sixth means 6 uses the value inputted from the fifth means 5 and uses the value inputted from the fifth means 5 for the light output wavelength characteristic at the time of direct modulation satisfying the predetermined extinction ratio and eye mask specification of the light emitting element. The coefficient of the linear function representing is calculated.

In (1-3), the sixth means 6 uses the value input from the fifth means 5 and uses the value inputted from the fifth means 5 for the optical output power characteristics at the time of direct modulation satisfying the predetermined extinction ratio and eye mask specification of the light emitting element. The coefficient of the linear function representing is calculated.

In (1-4), the sixth means 6 uses the value inputted from the fifth means 5 to obtain the RF amplitude characteristic at the time of direct modulation that satisfies the predetermined extinction ratio and eye mask definition of the light emitting element. Calculate the coefficient of the linear function to be represented.

In this case, the coefficients calculated in (1-2) to (1-4) are the drive current, element temperature, and light output wavelength at the time of direct modulation satisfying the predetermined extinction ratio and eye mask specification described above, respectively. , The relationship between the drive current at the time of direct modulation that satisfies the predetermined extinction ratio and eye mask specification, the relationship between the element temperature and the optical output power, and the drive current at the time of direct modulation that satisfies the predetermined extinction ratio and eye mask specification And a parameter value that determines the relationship between the element temperature and the RF amplitude.

  In (1-5), from the coefficients calculated in (1-2) and (1-3) and the specified optical output wavelength and optical output power, the equal optical output wavelength described in FIG. Using the fact that all the coefficients of the equation representing the line and the iso-optical output power line (primary equation) are determined, the coordinate values (drive current, element temperature) of the intersection of the two isolines are calculated from these coefficients. Then, the value of the RF amplitude is calculated from the calculated drive current and element temperature and the coefficient calculated in (1-4).

In the above example, for the sake of simplicity, the light output wavelength, light output power, and RF amplitude drive current dependency and device temperature dependency during direct modulation satisfying a predetermined extinction ratio and eye mask specification of the light emitting element are shown. In the above description, the planes (primary functions of the drive current and the element temperature) are well described. However, the light output wavelength and the light output power at the time of direct modulation satisfying the predetermined extinction ratio and the eye mask specification of the light emitting element. Even if the RF current drive current dependency and the element temperature dependency are well expressed by a quadratic curved surface, a more general function, or a plane or curved surface for each of a plurality of divided regions, the same procedure is used. It is possible to numerically determine the coefficient of the function representing each characteristic, and the effect of the present invention does not change.

[Embodiment 2]
17, the implementation of the second embodiment (however, not included in the scope of the appended claims.) Of the present invention shows the structure of a. This embodiment differs from the first embodiment shown in FIG. 15 in that a seventh means 7 and an eighth means 8 are provided instead of the sixth means 6.

The seventh means 7 monitors the drive current of the light-emitting elements constituting the first means 1 and compares and determines whether or not it is within the separately specified allowable fluctuation range. If it is not within the allowable fluctuation range, Drive current, element temperature, and optical output power at the time of direct modulation satisfying a predetermined extinction ratio of the light emitting element and an eye mask specification determined by at least one value for the light emitting element stored in the fifth means 5 From the relationship, the relationship between the drive current, the device temperature, and the optical output power when the drive current of the light emitting device varies is predicted, and is determined by at least one value for the light emitting device stored in the fifth means 5. From the relationship between the drive current, the element temperature, and the RF amplitude at the time of direct modulation that satisfies the predetermined extinction ratio and eye mask specification of the light emitting element, Predict relationships To.

Further, the eighth means 8 is a drive current at the time of direct modulation that satisfies a predetermined extinction ratio and eye mask specification of the light emitting element determined by at least one value for the light emitting element stored in the fifth means 5. , Device temperature and optical output wavelength, and the drive current and device temperature when the drive current fluctuates during direct modulation that satisfies the predetermined extinction ratio and eye mask definition of the light emitting device predicted by the seventh means 7 Both the optical output wavelength and optical output power during direct modulation that satisfy the specified extinction ratio and eye mask specification when the drive current of the light emitting element varies are separately specified for each from the relationship between the optical output power and the optical output power with predicting the latest drive current or optical output power and the latest device temperature to be the value that is, satisfying the predetermined extinction ratio and eye mask requirement of the expected light emitting element by means 7 of the seventh From the relationship between the drive current and device temperature and the RF amplitude during the driving current fluctuation during contact modulation, predicts the latest RF amplitude in the latest drive current or optical output power and the latest device temperature.

  Further, f is a driving current of the light emitting element constituting the first means 1, g is an allowable fluctuation range of the designated driving current, and h is a driving at the time of fluctuation of the driving current of the light emitting element predicted by the seventh means 7. A parameter value that determines the relationship between current, element temperature, and optical output power, and a parameter value that determines the relationship between drive current, element temperature, and RF amplitude, j is the latest driving current or optical output determined by the eighth means 8 Power, k is the latest RF amplitude determined by the eighth means 8, and l is the latest element temperature determined by the eighth means 8.

  FIG. 18 shows an operation procedure of the present embodiment.

First, (2-1), the at least one value of the optical output wavelength for the drive current and device temperature direct modulation time satisfying the predetermined extinction ratio and eye mask requirement stored in the means 5 of the fifth, Oh Alternatively, at least one parameter value that determines the relationship between these three components is read and output to the eighth means 8.

In (2-2), the eighth means 8 uses the at least one value input from the fifth means 5 to use a predetermined extinction ratio and eye mask definition for the light-emitting elements constituting the first means 1. The parameter value that determines the relationship among the drive current, the element temperature, and the optical output wavelength during direct modulation that satisfies the above is calculated.

In (2-3), at least one value of the optical output power for the drive current and device temperature direct modulation time satisfying the predetermined extinction ratio and eye mask requirement stored in the means 5 of the fifth, Oh Rui at least one parameter value for determining the these three relationships, and the predetermined extinction ratio and at least one value of the RF amplitude for the drive current and device temperature direct modulation time satisfying the eye mask requirement, Oh Rui these three At least one parameter value that determines the relationship is read out and output to the seventh means 7.

In (2-4), the seventh means 7 uses the at least one value input from the fifth means 5 to use a predetermined extinction ratio and eye mask prescription for the light-emitting elements constituting the first means 1. The parameter value that determines the relationship between the drive current, the element temperature, and the optical output power before the drive current fluctuation at the time of direct modulation that satisfies the above is calculated.

In (2-5), the seventh means 7 uses the at least one value input from the fifth means 5 to use a predetermined extinction ratio and eye mask definition for the light-emitting elements constituting the first means 1. The parameter value that determines the relationship between the drive current, the element temperature, and the RF amplitude before the drive current fluctuation at the time of direct modulation that satisfies the above is calculated.

  In (2-6), the seventh means 7 monitors the drive current f of the light emitting element constituting the first means 1, and determines whether or not this is within the allowable fluctuation range g of the drive current specified separately. Are compared.

  In (2-7), when the drive current f is within the allowable variation range, (2-6) is performed again, and when the drive current f is not within the allowable variation range, the operation proceeds to (2-8). Move.

In (2-8), in the seventh means 7, using the parameter value calculated in (2-4), a predetermined extinction ratio with respect to the light emitting element constituting the first means 1 when the drive current fluctuates and A parameter value that determines the relationship between the drive current, the element temperature, and the optical output power at the time of direct modulation that satisfies the eye mask specification is predicted, calculated, and output to the eighth means 8.

In (2-9), in the seventh means 7, using the parameter value calculated in (2-5), a predetermined extinction ratio with respect to the light emitting element constituting the first means 1 when the drive current fluctuates and A parameter value that determines the relationship between the drive current, the element temperature, and the RF amplitude at the time of direct modulation that satisfies the eye mask specification is predicted, calculated, and output to the eighth means 8.

In (2-10), based on the designated optical output wavelength and optical output power, the eighth means 8 uses the parameter value calculated in (2-2) and the parameter calculated in (2-8). Using the value h, the light output wavelength and the light output power at the time of direct modulation satisfying a predetermined extinction ratio and eye mask specification when the drive current of the light emitting element constituting the first means 1 is varied are simultaneously designated. b, the latest drive current or optical output power j and the latest element temperature l are calculated, and the parameter values calculated in the process of (2-9) are used to calculate the latest drive current or optical output power j and The latest RF amplitude k at the latest element temperature l is calculated.

  In (2-11), the drive current or optical output power j calculated in (2-10) is set as a new target value when the drive current fluctuates in the second means 2, and calculated in (2-10). The set element temperature 1 is similarly set to the third means 3 as a new target value, and the RF amplitude k calculated in (2-10) is set to the fourth means 4 as a new target when the drive current fluctuates. Set as a value. Thereafter, the process returns to (2-6).

  In this way, even when the drive current fluctuates, the light output wavelength and the light output power of the light output a from the first means 1 are automatically adjusted and controlled so as to have a separately designated value b. Can do.

  The operation procedures (2-1) to (2-5), (2-6) to (2-7), and (2-8) to (2-10) described above are performed as follows, for example. Can be realized.

First, the operation procedures (2-1) to (2-5) will be described. Here, the light output wavelength characteristic at the time of direct modulation that satisfies the predetermined extinction ratio and eye mask specification of the light emitting element is a plane (drive current and element in a three-dimensional space with the drive current, element temperature, and light output wavelength as coordinate axes. The light output power characteristic during direct modulation that is well expressed by the linear function of temperature and satisfies the predetermined extinction ratio and eye mask specification of the light emitting element is three-dimensional with the drive current, element temperature, and light output power as coordinate axes. The RF amplitude characteristic during direct modulation, which is well represented by a plane (linear function of drive current and element temperature) in the space and similarly satisfies a predetermined extinction ratio and eye mask definition of the light emitting element, is represented by the drive current, element temperature, and A case will be described in which a three-dimensional space with optical output power as a coordinate axis is well expressed by a plane (linear function of drive current and element temperature). The fifth means 5 includes values of the light output wavelength, the light output power, and the RF amplitude at the time of direct modulation satisfying a predetermined extinction ratio of the light emitting element with respect to a predetermined driving current and element temperature and an eye mask specification. The case of storing will be described as an example.

In (2-1), the value of the light output wavelength of the light emitting element at the time of direct modulation satisfying a predetermined extinction ratio and eye mask specification for the predetermined drive current and element temperature stored in the fifth means 5 is calculated. Read and input to the eighth means 8.

In (2-2), the light output wavelength characteristic of the light emitting element at the time of direct modulation that satisfies the predetermined extinction ratio and the eye mask definition using the value input from the fifth means 5 in the eighth means 8. The coefficient of the linear function representing is calculated.

Similarly, in (2-3), the optical output power of the light emitting element at the time of direct modulation satisfying a predetermined extinction ratio and eye mask specification stored in the fifth means 5 with respect to a predetermined drive current and element temperature. The value, the predetermined extinction ratio with respect to the determined drive current and element temperature, and the RF amplitude of the light emitting element at the time of direct modulation satisfying the eye mask definition are read out and input to the seventh means 7.

In (2-4), when the seventh means 7 uses the value input from the fifth means 5 during direct modulation satisfying a predetermined extinction ratio and eye mask prescription before the drive current fluctuation of the light emitting element. A coefficient of a linear function representing the light output power characteristic of the light emitting element is calculated.

In (2-5), the seventh means 7 uses the value input from the fifth means 5 during direct modulation satisfying a predetermined extinction ratio and eye mask definition before the drive current fluctuation of the light emitting element. A coefficient of a linear function representing the RF amplitude characteristic of the light emitting element is calculated. In this case, the coefficients calculated in (2-2), (2-4), and (2-5) are the driving current during direct modulation that satisfies the predetermined extinction ratio and eye mask specification described above, respectively. direct satisfying relationship of the element temperature and the optical output wavelength, the relationship between the predetermined extinction ratio and the drive current and device temperature and the optical output power of the direct modulation time satisfying the eye mask requirement, predetermined extinction ratio and eye mask requirement It is a parameter value that determines the relationship among drive current, element temperature, and RF amplitude during modulation.

  Next, operation procedures (2-6) to (2-7) will be described.

  In (2-6), a time average (moving average) over a predetermined short time is taken for the drive current of the light emitting element constituting the first means 1, or a low frequency having a predetermined cut-off characteristic A value obtained by performing filter processing for reducing instantaneous noise, such as passing through a band-pass filter or a high-frequency band cut-off filter, is compared with a specified drive current allowable fluctuation range.

  In (2-7), only when the result of the comparison / determination in (2-6) is not within the range for a predetermined number of times or more, or outside the range (2-8) , Go to (2-6) otherwise.

Here, the allowable fluctuation range of the drive current is separately designated, but the time average value over a long period of time for which the drive current is determined is i _av , the standard deviation is σ, the predetermined multiple is α, When the latest target value is i _new , i _av ± ασ or i _new ± ασ is calculated in the optical communication light source unit (for example, the seventh means 7 or the eighth means 8), and either of these is calculated. The effect of the present invention does not change even when the allowable fluctuation range of the drive current is reached.

  In addition, after a certain period of time has elapsed since the power was turned on and the light output of the light emitting element has stabilized, the light output power characteristics of the light emitting element are determined so as not to change over time, although it is a sufficiently long time. Even if the maximum value Max and the minimum value Min of the driving current in a long time are obtained by monitoring or the like, and the range determined by the Min and Max is set as the allowable fluctuation range of the driving current, the effect of the present invention does not change.

  Finally, the operation procedures (2-8) to (2-10) will be described.

In (2-8), when the monitored drive current is not within the specified allowable fluctuation range of the drive current based on the comparison determination result of (2-6), the calculation is performed in (2-4). , based on the coefficient of the linear function representing the light output power characteristics of the direct modulation time satisfying the predetermined extinction ratio and eye mask requirement before the drive current fluctuation of the light emitting element, predetermined extinction ratio when the drive current fluctuation and A coefficient of a linear function representing the optical output power characteristic at the time of direct modulation that satisfies the eye mask specification is predicted and calculated. That is, a coefficient of a linear function representing a plane obtained by translating a plane (linear function) representing the optical output power characteristics of the light emitting element along the coordinate axis relating to the drive current is predicted and calculated according to increase / decrease of the drive current. .

Next, in (2-9), the first order representing the RF amplitude characteristic at the time of direct modulation that satisfies the predetermined extinction ratio and eye mask prescription before the drive current fluctuation of the light emitting element calculated in (2-5). Based on the coefficient of the function, the coefficient of the linear function representing the RF amplitude characteristic at the time of direct modulation that satisfies the predetermined extinction ratio and eye mask specification when the drive current fluctuates is predicted and calculated. That is, the coefficient of the linear function representing the plane obtained by translating the plane (linear function) representing the RF amplitude characteristics of the light emitting element along the coordinate axis related to the drive current is predicted and calculated according to the increase or decrease of the drive current. In this case, the coefficient calculated in (2-8) is a parameter that determines the relationship among the drive current, element temperature, and optical output power during direct modulation that satisfies the predetermined extinction ratio and eye mask specification when the drive current fluctuates. Parameter that determines the relationship between the drive current, element temperature, and RF amplitude during direct modulation that satisfies the predetermined extinction ratio and eye mask specification when the drive current fluctuates. Value.

  In (2-10), from the coefficients calculated in (2-2) and (2-8) and the specified optical output wavelength and optical output power, the equal optical output wavelength line and the drive current fluctuation, etc. Utilizing the fact that all the coefficients of the equation representing the optical output power line (primary equation) are determined, from these coefficients, the coordinate value (drive current, element temperature) of the intersection of two isolines is used when the drive current fluctuates. Calculate the latest drive current or optical output power and the latest device temperature at. The latest RF amplitude is calculated using the calculated latest drive current or optical output power and the latest element temperature, and the coefficient calculated in (2-9).

In the above example, for the sake of simplicity, the light output wavelength, light output power, and RF amplitude drive current dependency and device temperature dependency during direct modulation satisfying a predetermined extinction ratio and eye mask specification of the light emitting element are shown. In the above description, the planes (primary functions of the drive current and the element temperature) are well described, but the light output wavelength of the light emitting element, the light output power, and the RF amplitude drive current dependence and element temperature dependence are described. Even when a quadratic curved surface, a more general function, or a plane or curved surface is better expressed for each of a plurality of divided areas, the coefficient of the function representing each characteristic is numerically expressed using the same procedure. Since it can be determined, the effect of the present invention does not change.

[Embodiment 3]
19, the implementation of the third (but not included in the scope of the appended claims.) Of the present invention shows the structure of a. In the second embodiment shown in FIG. 17, the latest drive current or optical output power j determined by the eighth means 8, the latest RF amplitude k, and the latest element temperature l are stored. The difference is that the means 9 is added.

  The operation procedure of the present embodiment is shown in FIG. A portion different from the operation procedure of FIG. 18 will be mainly described.

  First, in (3-1), it is determined whether or not to use the value stored in the ninth means 9 in consideration of the case where the light source for optical communication is warm-started.

  When used, the latest drive current or optical output power j, RF amplitude k and element temperature l determined by the eighth means 8 are stored in the ninth means 9 in (3-2). Determine whether or not.

  If the latest drive current or optical output power j determined by the eighth means 8, the element temperature l and the RF amplitude k are stored in the ninth means 9, those (3-3) The values are read and output to the second means 2, the third means 3, and the fourth means 4, respectively.

  Thereafter, in (3-15), in the second means 2, the third means 3, and the fourth means 4, the respective values input from the ninth means 9 are set as target values.

  On the other hand, when the value stored in the ninth means 9 is not used, or the latest drive current or optical output power j, RF amplitude k, and element temperature determined by the eighth means 8 in the ninth means 9 When l is not stored, steps (3-4) to (3-13) are the same as steps (2-1) to (2-10) in the second embodiment, respectively.

  After that, in (3-14), the latest drive current or optical output power j determined in (3-13), the latest RF amplitude k, and the latest element temperature l are stored in the ninth means 9. The next (3-15) is the same as the procedure (2-11) in the second embodiment.

  In the present embodiment, the case where the optical communication light source unit having the configuration of the second embodiment is warm-started is considered, but even if the optical communication light source unit having the configuration of the first embodiment is warm-started, The effect of the present invention is not changed.

[Embodiment 4]
Figure 21 is a form of implementation of the present invention 4 (however, not included in the scope of the appended claims.) Shows the structure of a. The configuration of the third embodiment shown in FIG. 19 is to monitor the optical output wavelength and / or the optical output power of the optical output a from the first means 1, and separately specify the optical output wavelength specified separately. A difference is that a tenth means 10 for comparing and determining whether or not the output power range is within the range and the optical output power range and outputting the comparison determination result is added. In the present embodiment, a case will be described in which both the optical output wavelength and the optical output power are compared and determined.

  FIG. 22 shows an operation procedure of the present embodiment.

  First, in the same procedure as the operation procedures (3-1) to (3-15) in the third embodiment, the drive current or the optical output power, the RF amplitude so as to obtain the designated optical output wavelength and optical output power b. In addition, the device temperature is set, adjusted, and controlled, and the optical output wavelength and optical output power of the optical output a from the first means 1 are monitored in parallel.

  In (4-1), the light from the first means 1 driven by the latest drive current or optical output power j determined by the eighth means 8, the latest element temperature l, and the latest RF amplitude k. Both the optical output wavelength and the optical output power of the output a are monitored using the tenth means 10.

  Next, in (4-2), the optical output wavelength and optical output power monitored in (4-1) are compared with the separately specified optical output wavelength range and optical output power range m, respectively.

  When the determination is made in (4-3) and the monitored optical output wavelength and optical output power are within the specified optical output wavelength range and optical output power range, the comparison determination result n in (4-4). Is output as a status display, and the process returns to (4-1).

  If the monitored optical output wavelength and optical output power are not within the specified optical output wavelength range and optical output power range, the comparison determination result n is output as an abnormality alarm in (4-5), ( Return to 4-1).

  Among the operation procedures described above, (4-1) can be realized as follows, for example. The light output a from the first means 1 is input to a light wavelength band transmitting means such as an optical filter that transmits light in a designated light output wavelength range. This output is further input to a photoelectric conversion means such as a photodiode that converts the optical power of the input light into a photocurrent. By monitoring and comparing the photocurrents thus obtained, the optical output wavelength and the optical output power are monitored and compared. That is, the optical wavelength transmission characteristics of the optical wavelength band transmission means and the conversion characteristics of the photoelectric conversion means, the photocurrent range determined from the specified optical output wavelength range and optical output power range, and the previous monitoring. The comparison described above is performed by comparing the obtained photocurrent.

  In the present embodiment, the case where the optical output wavelength and the optical output power of the optical communication light source unit having the configuration of the third embodiment is monitored has been described. However, for optical communication having the configuration of the first or second embodiment. Even when the light output wavelength and light output power of the light source unit are monitored, the effect of the present invention does not change.

As described above, in Embodiments 1 to 4, the case where the first means 1 is configured by one light emitting element has been described for the sake of simplicity. However, the first means 1 is configured by a plurality of light emitting elements. The second means 2 automatically controls the driving current or the optical output power of each light emitting element so as to keep the target value given thereto, and the third means 3 controls the element temperature of each light emitting element for each. Even when the fourth means 4 automatically controls to maintain the given target value and the fourth means 4 automatically controls to keep the RF amplitude of each light emitting element at the given target value for each, the fifth means 5 in, in each light emitting device constituting the first means 1, at least one value of the optical output wavelength for the drive current and device temperature direct modulation time satisfying the predetermined extinction ratio and eye mask requirement, the Oh Rui these 3 To determine the relationship Both the single parameter values, at least one of determining the predetermined extinction ratio and at least one value of the optical output power for the drive current and device temperature direct modulation time satisfying the eye mask requirement, Oh Rui of these three related one of the parameter values, at least one value of the RF amplitude for a given extinction ratio and the drive current and device temperature of the direct modulation time satisfying the eye mask requirement, Oh Rui least one parameter value for determining the these three relationships In the sixth means 6, a predetermined value for each light-emitting element determined by at least one value for each light-emitting element constituting the first means 1 stored in the fifth means 5 is stored. and the relationship between the drive current and device temperature and the optical output wavelength of the direct modulation time satisfying the extinction ratio and eye mask requirement, predetermined extinction ratio and eye mask requirement of each respective light emitting element From the relationship between the drive current, the element temperature, and the optical output power at the time of satisfying direct modulation, the drive current or the optical output power at which both the optical output wavelength and the optical output power of each light emitting element are separately designated values and The element temperature is determined, and is determined from the relationship between the drive current, the element temperature, and the RF amplitude when the drive current fluctuates during direct modulation that satisfies the predetermined extinction ratio and eye mask specification for each light emitting element. by the Ruco to determine the RF amplitude in the drive current or optical output power and device temperature, the first means 1 setting of the optical output wavelength and optical output power of each light emitting device constituting the, as well as predetermined extinction ratio and eye mask It is possible to achieve the regulation in the same manner, and the seventh means 7 monitors the drive current of each light emitting element constituting the first means 1 and is within an allowable fluctuation range separately designated for each light emitting element. If the light emitting element is not within the allowable variation range, the predetermined extinction of the light emitting element determined by at least one value for the light emitting element stored in the fifth means 5 is determined. From the relationship between the drive current, element temperature, and optical output power during direct modulation that satisfies the ratio and eye mask regulations, the relationship between the drive current, element temperature, and optical output power when the drive current of the light-emitting element varies is predicted. The drive current, element temperature, and RF amplitude at the time of direct modulation satisfying a predetermined extinction ratio of the light emitting element and an eye mask defined by at least one value for the light emitting element stored in the fifth means 5 From the relationship, the relationship between the drive current, the element temperature, and the RF amplitude when the drive current of the light emitting element is varied is predicted. In the eighth means 8, the light emitting element that is not within the allowable variation range is Means At least determined by one value, the relationship between the predetermined extinction ratio and the drive current and device temperature and the optical output wavelength of the direct modulation time satisfying the eye mask requirement of the light emitting element against the stored light emitting element, the seventh From the relationship between the driving current, the element temperature, and the optical output power at the time of fluctuation of the driving current during direct modulation that satisfies the predetermined extinction ratio of the light emitting element predicted by the means 7 and the eye mask definition, Latest driving current or optical output power in which both the optical output wavelength and optical output power during direct modulation satisfying a predetermined extinction ratio and eye mask specification when the driving current fluctuates are values specified separately for each light emitting element and thereby predicting the latest device temperature, driving at the time of driving current fluctuation of direct modulation time satisfying the predetermined extinction ratio and eye mask requirement of the expected light emitting element by means 7 of the seventh From the relationship between the current and device temperature and the RF amplitude, for each light emitting device constituting a and benzalkonium predict the latest RF amplitude in the latest drive current or optical output power and the latest device temperature, the first means 1 The adjustment and control of the light output wavelength and the light output power, and the achievement of the predetermined extinction ratio and the eye mask definition can be similarly achieved. In the ninth means 9, the second means, by latest in our store value Ku means and the target value given respectively to the fourth means, for warm start of the optical output wavelength and optical output power of each light emitting device constituting the first means 1 The setting, adjustment, and control including the case can be similarly performed, and the tenth means 10 monitors the light output generated by each light emitting element constituting the first means 1, and the light of the light output is monitored. Output wavelength and optical output For power both or either, and the comparison determination whether or not separately specified optical output wavelength range and optical output power range for each, by the Turkey to output the comparison determination result, the first The light output wavelength and / or light output power for each light-emitting element constituting the means 1 can be monitored in the same manner, and the effect of the present invention does not change.

  The light output wavelengths separately designated for the plurality of light emitting elements constituting the first means 1 are usually different from each other, but any light output wavelengths including cases where they are all the same or partially the same are designated for each. It goes without saying that it is possible. Similarly, the optical output power separately designated for the plurality of light emitting elements constituting the first means 1 is usually the same, but any optical output power including cases where they are all different or partially different is assigned to each. Needless to say, it can be specified.

  In the first to fourth embodiments, the case where at least one value itself (raw value) is stored in the fifth means 5 has been described, but all or at least one of these values is normalized in advance. , Scramble, bit inversion, encryption, etc. are performed, stored in the fifth means 5, read out from the fifth means 5, and then de-standardized, descrambled, bit inversion, encryption / decryption, respectively. The effect of the present invention does not change even when the decoding process such as the above is used.

  Similarly, in the third embodiment, the latest drive current or optical output power j, the latest RF amplitude k, and the latest element temperature l itself (raw value) determined by the eighth means 8 are the ninth. Although the case of storing in the means 9 has been described, all or at least one of these values is subjected to encoding processing such as normalization, scramble, bit inversion, encryption and the like and stored in the ninth means 9 in advance. The effect of the present invention does not change even when the data is used after being read from the ninth means 9 and then subjected to decryption processing such as non-standardization, descrambling, bit inversion, and encryption / decryption.

  In the second and third embodiments, the driving current is monitored in the steps (2-6) and (3-9), respectively. However, the fluctuation amount from the target value or average value of the driving current is changed. Even if it monitors, the effect of this invention does not change.

  In the first to fourth embodiments, the second means for automatically controlling the optical output power by a feedback control or the like so as to keep the optical output power at a given target value, that is, the optical power directly by the automatic power control circuit (APC). The case of controlling the output power has been described as an example, but the effect of the present invention does not change even when the optical output power is indirectly controlled using an automatic current control circuit (ACC).

  Furthermore, in the fourth embodiment, the effect of the present invention does not change whether the comparison determination is executed and the result output is either the optical output wavelength or the optical output power. Furthermore, even when only one or both of the status display and the abnormality alarm is output for each of the optical output wavelength and the optical output power, the effect of the present invention does not change.

  Further, the procedures (1-2), (1-3), and (1-4) in the first embodiment, and the procedures (2-1) to (2-2) and (2-3) in the second embodiment. (2-5), (2-4) and (2-5), (2-8) and (2-9), procedures (3-4) to (3-5) in Embodiment 3 (3-6) to (3-8), (3-7) and (3-8), (3-11) and (3-12), (3-14) and (3-15) The effect of the present invention does not change even if the execution order is changed.

  In addition, in the first to fourth embodiments, the case where a new target value of the drive current of the light emitting element is explicitly given has been described. However, the automatic power control circuit (APC) is autonomously operated to obtain the drive current. Even when fine adjustment is made, the effect of the present invention does not change.

  In the first to fourth embodiments, the case where the new target value of the RF amplitude of the light emitting element is explicitly given has been described. However, the automatic bias control circuit (ABC) is operated autonomously to further increase the RF amplitude. Even when fine adjustment is made, the effect of the present invention does not change.

In the first to fourth embodiments, the dependency of the optical output power upon direct modulation that satisfies the predetermined extinction ratio and the eye mask specification when the driving current fluctuates on the driving current and the element temperature is the same as that before the driving current fluctuates. The dependency is well expressed by the parallel movement according to the fluctuation amount of the drive current, but the coefficient of the term relating to the drive current in the characteristic equation representing the dependency and the element temperature of the equation. Even when both or either of the terms are converted according to the amount of fluctuation of the driving current, such as by changing the coefficient according to the amount of fluctuation of the driving current, the effect of the present invention can be expressed. Will not change.

In the first to fourth embodiments, the dependency of the RF amplitude upon direct modulation that satisfies the predetermined extinction ratio and eye mask specification when the drive current fluctuates on the drive current and the element temperature is the same as that before the drive current fluctuates. Although the dependency is well expressed by the parallel movement according to the fluctuation amount of the drive current, the coefficient of the term relating to the drive current in the equation of the characteristic surface representing the dependency, and the term relating to the element temperature of the equation Even when the dependency is converted according to the amount of fluctuation of the drive current, such as by converting either or both of the coefficients according to the amount of fluctuation of the drive current, the effect of the present invention is effective. does not change.

[Embodiment 5]
Figure 23 is a diagram illustrating the method of implementation of the present fifth invention. This embodiment satisfies the drive current and element temperature dependence of the light output wavelength during direct modulation that satisfies the predetermined extinction ratio and eye mask definition of the light emitting element, and satisfies the predetermined extinction ratio and eye mask definition of the light emitting element. Dependence of drive current and device temperature on optical output power during direct modulation, and drive current and device temperature dependence of RF amplitude during direct modulation satisfying predetermined extinction ratio and eye mask specification of light emitting device Shows how to select measurement points.

In (5-1), the operating range of the drive current i specified separately (i ₁ ≦ i ≦ i ₂ ) and the operating range of the element temperature T (T ₁ ≦ T ≦ T) of the light-emitting elements constituting the first means. ₂ ) Enter.

In (5-2), an arbitrary value of p (p is a ratio coordinate of the internal dividing point of the operating range of the driving current i of the light emitting element and is a real number satisfying 0 <p <1) is used. As shown in (a), the operation range (i ₁ ≦ i ≦ i ₂ ) of the designated drive current i is expressed as p: 1−p and 1 on a two-dimensional plane having the drive current and the optical output wavelength as coordinate axes. -P: The drive currents i _s1 and i _s2 at the internal dividing point obtained by dividing internally by p are obtained, and from this, the secondary of the drive current at the time of direct modulation satisfying the predetermined extinction ratio and eye mask definition of the light emitting element Minimum and maximum approximation errors between the optical output wavelength characteristic expressed by the function and the optical output wavelength characteristic approximated by the linear function of the drive current, that is, | δλ ₀ | _{i = i1 or i2} and | δλ _{0 I = (i1 + i2) / 2} is obtained, the value of p is determined so that they are equal, and the driving currents i _s1 and i _s2 are determined using the internal dividing point at this time as the measurement point. Is determined as the drive current at the measurement point.

In (5-3), using the value of p determined in the process of (5-2), the operating range of the element temperature T of the light emitting element (T ₁ ≦ T ≦ T ₂ ) is set to p: 1−p and 1 -P: The element temperature internally divided by p is determined as element temperatures T _s1 and T _s2 at the measurement point.

Finally, in (5-4), four measurement points (i _s1 , T _s1 ), (i _s1 , T _s2 ) composed of combinations of values determined in the process of (5-2) to (5-3). ), (I _s2 , T _s1 ), (i _s2 , T _s2 ), arbitrary three points are optical output wavelength characteristics at the time of direct modulation satisfying a predetermined extinction ratio and eye mask regulations, optical output power characteristics, and Select as a measurement point for RF amplitude characteristics.

In this way, for the light emitting element in the light source unit for direct modulation optical communication, the drive current and element temperature dependence of the optical output power at the time of direct modulation that satisfies the predetermined extinction ratio and eye mask specification are determined. By selecting these measurement points, it is possible to reduce the estimation error of the optical output wavelength and optical output power when setting and controlling the optical output wavelength, RF amplitude and optical output power.

[Embodiment 6]
Figure 24 is a view showing an actual method of facilities according to the sixth invention. The difference from the method of the fifth embodiment shown in FIG. 23 is that the steps (6-1) and (6-4) are the same as the steps (5-1) and (5-4) in the fifth embodiment, respectively. However, the processes (6-2) to (6-3) are different. In the following, portions different from the fifth embodiment in FIG. 23 will be mainly described.

In (6-2), an arbitrary q value (q is a ratio coordinate of the internal dividing point of the operating range of the element temperature T of the light emitting element, and is a real number satisfying 0 <q <1) is used. As shown in (b), the operating range (T ₁ ≦ T ≦ T ₂ ) of the specified element temperature T is expressed as q: 1−q and 1 on a two-dimensional plane having the element temperature and the light output wavelength as coordinate axes. -Q: The element temperature T _s1 and T _s2 at the internal dividing point is obtained by dividing internally by q, and the second order element temperature during direct modulation satisfying a predetermined extinction ratio and eye mask definition of the light emitting element from this The minimum and maximum approximation errors between the optical output wavelength characteristic expressed by the function and the optical output wavelength characteristic approximated by the linear function of the element temperature, that is, | δλ ₀ | _{T = T1 or T2} and | δλ _{0 T = (T1 + T2) / 2} is determined, the value of q is determined so that they are equal, and the element temperatures T _s1 and T _s2 are measured using the internal dividing point at this time as the measurement point. Is determined as the element temperature at the measurement point.

In (6-3), using the value of q determined in the process of (6-2), the operating range (i ₁ ≦ i ≦ i ₂ ) of the driving current i of the light emitting element is changed to q: 1-q and 1 -Q: The driving current divided internally by q is determined as the driving currents i _s1 and i _s2 at the measurement point.

As described above, in the fifth embodiment, the optical output wavelength characteristic represented by the quadratic function of the drive current at the time of direct modulation that satisfies the predetermined extinction ratio and the eye mask specification, and the linear function of the drive current are approximated. In order to reduce the approximation error with the optical output wavelength characteristic, the drive current at the measurement point is determined. In the sixth embodiment, the element temperature is second-order in direct modulation satisfying a predetermined extinction ratio and eye mask specification. and optical output wavelength characteristics expressed by the function, in order to reduce the approximation error between the optical output wavelength characteristics approximated by a linear function of the element temperature has been determined element temperature at the measuring point, predetermined extinction ratio and In order to reduce the approximation error between the optical output power characteristic represented by the quadratic function of the drive current during direct modulation that satisfies the eye mask specification and the optical output power characteristic approximated by the linear function of the drive current, Drive current at measurement point Be determined, or the optical output power characteristics expressed by the quadratic function of the element temperature of the direct modulation time satisfying the predetermined extinction ratio and eye mask requirement, the optical output which is approximated by a linear function of the device temperature Even if the element temperature at the measurement point is determined in order to reduce the approximation error with the power characteristic, it is further expressed by a quadratic function of the drive current at the time of direct modulation that satisfies a predetermined extinction ratio and eye mask specification. In order to reduce the approximation error between the RF amplitude characteristic and the RF amplitude characteristic approximated by a linear function of the drive current, even if the drive current at the measurement point is determined, or a predetermined extinction ratio and eye mask are specified. In order to reduce the approximation error between the RF amplitude characteristic represented by the quadratic function of the element temperature at the time of satisfying direct modulation and the RF amplitude characteristic approximated by the linear function of the element temperature, the element temperature at the measurement point is reduced. Even if decided Since the results obtained, the effect of the present invention is not changed.

In the fifth and sixth embodiments, the light output wavelength characteristic, the light output power characteristic, and the RF amplitude characteristic at the time of direct modulation satisfying the predetermined extinction ratio and the eye mask specification of the light emitting element are set within the operating range. Considering up to quadratic terms for each element temperature (as a quadratic function of the drive current and element temperature), the light output wavelength of the light-emitting element during the actual setting / control of the light output wavelength, light output power and RF amplitude The case where the drive current dependency and element temperature dependency of the characteristics, optical output power characteristics, and RF amplitude characteristics are approximated by a plane (linear function of drive current and element temperature) has been described. Even when the range is divided into multiple regions and each of the divided regions is approximated by a plane, the same procedure is used to calculate the maximum and minimum absolute values of the approximation error of the function representing each characteristic. value Since it is possible to select the equal drive current and device temperature of the measuring points, the effect of the present invention is not changed.

In the fifth to sixth embodiments, the case where the first means is configured by one light emitting element has been described for the sake of simplicity. However, the first means 1 is configured by a plurality of light emitting elements, and the second Means 2 automatically controls the drive current or optical output power of each light emitting element to maintain the target value given to each, and the third means 3 gives the element temperature of each light emitting element to each. The fourth means 4 automatically controls the RF amplitude of each light emitting element to be kept at the target value given to each, and the fifth means 5 is the first control. in each light emitting device constituting the means 1, the predetermined extinction ratio and at least one value of the optical output wavelength for the drive current and device temperature direct modulation time satisfying the eye mask requirement, Oh Rui these 3's relationship At least one parameter value to be determined , At least one value of the optical output power for the drive current and device temperature direct modulation time satisfying the predetermined extinction ratio and eye mask requirement, Oh Rui at least one parameter value for determining the these three relations, a given at least one value of the RF amplitude for the extinction ratio and the drive current and device temperature of the direct modulation time satisfying the eye mask requirement, Oh Rui stores at least one parameter value for determining the these three relationships, the The sixth means 6 satisfies a predetermined extinction ratio and eye mask definition for each light emitting element, which is determined by at least one value for each light emitting element constituting the first means 1 stored in the fifth means 5. and the relationship between the drive current and device temperature and the optical output wavelength of the direct modulation time, the driving current of the direct modulation time satisfying the predetermined extinction ratio and eye mask requirement of each respective light emitting element and the element temperature From the relationship between the light output power and the light output power, the drive current or light output power and the device temperature at which both the light output wavelength and the light output power of each light emitting device are separately specified values are determined, and each light emitting device From the relationship between the drive current, the element temperature, and the RF amplitude at the time of direct current modulation satisfying a predetermined extinction ratio and eye mask definition for each, the determined drive current or optical output power and RF at the element temperature are determined. Even when the amplitude is determined, the seventh means 7 monitors the drive current of each light emitting element constituting the first means 1 and is within an allowable variation range separately designated for each light emitting element. A light-emitting element that is not within the allowable variation range is determined by at least one value for the light-emitting element stored in the fifth means 5 and a predetermined extinction ratio and eye of the light-emitting element. Mask rules A relationship between the drive current, the element temperature, and the optical output power when the drive current of the light emitting element varies is predicted from the relationship between the drive current, the element temperature, and the optical output power at the time of direct modulation that satisfies From the relationship between the drive current, the element temperature, and the RF amplitude at the time of direct modulation satisfying a predetermined extinction ratio of the light emitting element and an eye mask rule determined by at least one value for the light emitting element stored in 5 The relationship between the drive current, the element temperature, and the RF amplitude when the element drive current fluctuates is predicted, and the eighth means 8 is stored in the fifth means 5 for light emitting elements that are not within the allowable fluctuation range. The relationship between the drive current, the element temperature, and the light output wavelength during direct modulation satisfying a predetermined extinction ratio and eye mask definition of the light emitting element, which is determined by at least one value for the light emitting element, and seventh means 7 Due to And a relationship between the drive current and device temperature and the optical output power during the drive current fluctuation of the direct modulation at satisfying been a predetermined extinction ratio and eye mask requirement of the light emitting element, when the drive current fluctuation of the light emitting element Predicts the latest drive current or optical output power and latest device temperature at which both the optical output wavelength and optical output power during direct modulation satisfying the prescribed extinction and eye mask specifications are separately specified for each light emitting device In addition, from the relationship between the drive current, the element temperature, and the RF amplitude at the time of the drive current fluctuation at the time of direct modulation satisfying the predetermined extinction ratio of the light emitting element predicted by the seventh means 7 and the eye mask specification, the latest Even when the latest RF amplitude at the latest driving current or optical output power and the latest device temperature is predicted, the ninth means 9 is provided with the second means, the third means and the fourth means for each light emitting element. Even when the latest value of the target value given to each stage is stored, the tenth means 10 monitors the light output generated by each light-emitting element constituting the first means 1, and the light output When comparing and determining whether the optical output wavelength and / or optical output power are within the optical output wavelength range and optical output power range specified separately for each, and outputting the comparison determination result But, by the Turkey to perform the first through fourth processes of the fifth or sixth embodiment for each light-emitting element, the optical output wavelength characteristics of the plurality of the light emitting device constituting the first means, the optical output power characteristics and The measurement point of the RF amplitude characteristic can be selected similarly, and the effect of the present invention is not changed.

In Embodiments 5 and 6, in order to set and control the light output wavelength and the light output power during direct modulation that satisfy the predetermined extinction ratio and eye mask specification, the light output wavelength of the light emitting element is driven. Measurement points are selected to determine the current and element temperature dependence, the driving current and element temperature dependence of the light output power of the light emitting element, and the driving current and element temperature dependence of the RF amplitude of the light emitting element. When measuring points to determine the drive current and element temperature dependence of the light output wavelength of the light emitting element during direct modulation that satisfies the specified extinction ratio and eye mask regulations in order to monitor the output wavelength only However, the effect of the present invention does not change.

  In the fifth and sixth embodiments, the case where at least one value itself (raw value) is stored in the fifth means 5 has been described. However, all or at least one of these values is normalized in advance. , Scramble, bit inversion, encryption, etc. are performed, stored in the fifth means 5, read out from the fifth means 5, and then de-standardized, descrambled, bit inversion, encryption / decryption, respectively. The effect of the present invention does not change even when the decoding process such as the above is used.

Also, in the fifth and sixth embodiments, the latest drive current or optical output power j determined by means 8 of the eighth, the latest RF amplitude k and the latest device temperature l itself (raw value) first Although the case where the data is stored in the ninth means 9 has been described, all or at least one of these values is subjected to encoding processing such as normalization, scramble, bit inversion, encryption, etc., and stored in the ninth means 9 in advance. In addition, the effect of the present invention does not change even when the data is read after being read from the ninth means 9 and then used after being subjected to decryption processing such as non-standardization, descrambling, bit inversion, and encryption / decryption.

  In the fifth and sixth embodiments, there is a case where the optical output power is automatically controlled by feedback control or the like so as to keep the optical output power at a given target value, that is, directly controlled by an automatic power control circuit (APC). Although described as an example, the effect of the present invention does not change even when control is performed using an automatic current control circuit (ACC).

  In the fifth and sixth embodiments, the case where a new target value of the RF amplitude of the light emitting element is explicitly given has been described. However, the automatic bias control circuit (ABC) is operated autonomously to further increase the RF amplitude. Even when fine adjustment is made, the effect of the present invention does not change.

Configuration diagram showing an example of a light source unit for optical communication according to the prior art Explanatory drawing showing the outline of setting and control of optical output wavelength by conventional technology Explanatory drawing which shows the relationship of the optical output wavelength with respect to the drive current and element temperature of a light emitting element, and optical output power (before drive current fluctuation) Explanatory drawing which shows the relationship of the optical output wavelength with respect to the drive current and element temperature of light emitting element, and optical output power (at the time of drive current fluctuation) Configuration diagram showing an example of a light source unit for optical communication described in the prior application 1 The block diagram which shows an example of the light source part for optical communication described in the prior application 2 Illustration of approximate error of light output wavelength in the operating range of light emitting element Explanatory drawing which shows the relationship between the ratio coordinate of the internal dividing point of a drive current operation range, and the ratio of the absolute value of optical output wavelength approximation error Explanatory drawing which shows the relationship between the operating range of a light emitting element, and the measurement point of optical output wavelength characteristic and optical output power characteristic Explanatory drawing which shows the measurement example of the eye pattern at the time of direct modulation of a light emitting element Explanatory drawing which shows the relationship of the RF amplitude with respect to the drive current and element temperature at the time of the direct modulation which satisfy | fills predetermined extinction ratio and eye mask prescription | regulation of a light emitting element Illustration of approximate error of light output wavelength in the operating range of light emitting element Explanatory drawing of approximate error of optical output power or RF amplitude in the operating range of light emitting element Explanatory drawing which shows the relationship between the operating range of a light emitting element, and the measurement point of optical output wavelength characteristic, optical output power characteristic, and RF amplitude characteristic 1 is a block diagram showing a first embodiment of a direct modulation type communication light source unit according to the present invention. Flowchart showing the operation procedure of the first embodiment The block diagram which shows Embodiment 2 of the light source part for direct modulation type communication by this invention Flowchart showing the operation procedure of the second embodiment The block diagram which shows Embodiment 3 of the light source part for direct modulation | alteration type | molds by this invention A flowchart showing an operation procedure of the third embodiment. The block diagram which shows Embodiment 4 of the light source part for direct modulation type communication by this invention The flowchart which shows the operation | movement procedure of Embodiment 4. The flowchart which shows the procedure of the process of Embodiment 5 of this invention. The flowchart which shows the procedure of the process of Embodiment 6 of this invention.

Explanation of symbols

  1: first means, 2: second means, 3: third means, 4: fourth means, 5: fifth means, 6: sixth means, 7: seventh means, 8 : Eighth means, 9: ninth means, 10: tenth means, a: optical output from the first means 1, b: designated optical output wavelength and optical output power, c: sixth Drive current or optical output power determined by means 6, d: RF amplitude determined by sixth means 6, e: element temperature determined by sixth means 6, f: first means 1 is configured Driving current of the light emitting element to be operated, g: allowable fluctuation range of the designated driving current, h: relationship between the driving current, the element temperature, and the optical output power at the time of the driving current fluctuation of the light emitting element predicted by the seventh means 7 A parameter value that determines the relationship between drive current, element temperature, and RF amplitude, j: by the eighth means 8 The latest driving current or optical output power determined, k: latest RF amplitude determined by the eighth means 8, l: latest element temperature determined by the eighth means 8, m: designated light Output wavelength range and / or optical output power range, n: Comparison determination result.

Claims (12)

A first means configured to generate a light output, and a second means for automatically controlling the driving current or the light output power of the light emitting element constituting the first means to be kept at a given target value. Means, a third means for automatically controlling the element temperature of the light emitting element constituting the first means to maintain a given target value, and the RF amplitude of the light emitting element constituting the first means And a light source unit for direct modulation optical communication having a fourth means for automatically controlling to maintain a given target value,
To the light emitting elements constituting the first means, at least one value of the optical output wavelength for the drive current and device temperature direct modulation time satisfying the predetermined extinction ratio and eye mask requirement, Oh Rui of these three at least one parameter value for determining the relationship, the predetermined at least one value of the extinction ratio and optical output power for the drive current and device temperature direct modulation time satisfying the eye mask requirement, Oh Rui of these three related at least one parameter value determining, at least to determine the predetermined extinction ratio and at least one value of the RF amplitude for the drive current and device temperature direct modulation time satisfying the eye mask requirement, Oh Rui of these three related Fifth means for storing one parameter value;
A drive current, element temperature, and light output wavelength at the time of direct modulation satisfying a predetermined extinction ratio of the light emitting element and an eye mask specification determined by at least one value for the light emitting element stored in the fifth means Both the light output wavelength and the light output power of the light emitting element from the relationship and the relationship between the drive current, the element temperature and the light output power during direct modulation satisfying the predetermined extinction ratio and eye mask specification of the light emitting element. Determines the driving current or optical output power and element temperature at which the value of the light emitting element is separately designated, and the driving current and the element when the driving current fluctuates during direct modulation satisfying the predetermined extinction ratio and eye mask specification of the light emitting element A sixth means for determining the determined drive current or optical output power and the RF amplitude at the element temperature from the relationship between the temperature and the RF amplitude;
The driving current or optical output power of the light emitting element, the element temperature and the RF amplitude determined by the sixth means are the target values for the light emitting element in the second means, third means and fourth means, respectively. in direct modulation type optical communication light source unit Ru provided as a predetermined extinction ratio and direct modulation at the optical output that satisfies the eye mask requirement of the light emitting device constituting the first means to be stored in the fifth means A method for selecting measurement points (drive current, element temperature) of wavelength characteristics, optical output power characteristics and RF amplitude characteristics,
A first step of inputting an operation range (i ₁ ≦ i ≦ i ₂ ) of a separately designated drive current i and an operation range (T ₁ ≦ T ≦ T ₂ ) of the element temperature T;
Using an arbitrary value of p (p is a ratio coordinate of the internal dividing point of the operating range of the driving current i of the light emitting element, and a real number satisfying 0 <p <1), the operation of the designated driving current i The range (i ₁ ≦ i ≦ i ₂ ) is internally divided by p: 1-p and 1-p: p to determine drive currents i _s1 and i _s2 at the internal dividing points, and from this, a predetermined value of the light emitting element is determined. Minimum value of the approximation error between the optical output wavelength characteristic with respect to the driving current during direct modulation that satisfies the extinction ratio and the eye mask specification, and the optical output wavelength characteristic approximated by a linear function of the driving current | δλ ₀ | _{i = i1 or i2} and the maximum value | δλ ₀ | _{i = (i1 + i2) / 2} , and determine the value of p so that they are equal to each other, or from this, a predetermined extinction ratio and eye mask definition of the light emitting element Nearly satisfied optical output power characteristics with respect to drive current during direct modulation and optical output power characteristics approximated by a linear function of drive current The minimum value | δP ₀ | _{i = i1 or i2} and the maximum value | δP ₀ | _{i = (i1 + i2) / 2} of the similar error are obtained, and the value of p is determined so that they are equal, or from this Minimum value of approximation error between RF amplitude characteristic with respect to drive current during direct modulation satisfying predetermined extinction ratio and eye mask definition of light emitting element and RF amplitude characteristic approximated by linear function of drive current | δi _RF0 | _{i = i1 or i2} and the maximum value | δi _RF0 | _{i = (i1 + i2) / 2} are determined, and the value of p is determined so that they are equal. a second step of determining i _s1 and i _s2 as drive currents at the measurement points;
A measuring point is an element temperature at which the operating range of the specified element temperature T (T ₁ ≦ T ≦ T ₂ ) is internally divided by p: 1−p and 1−p: p using the determined value of p. A third step of determining as element temperatures T _s1 and T _s2 at
Of the four measurement points (i _s1 , T _s1 ), (i _s1 , T _s2 ), (i _s2 , T _s1 ), (i _s2 , T _s2 ) composed of the determined value combinations, any 3 And a fourth process of selecting a point as a measurement point of the optical output wavelength characteristic, optical output power characteristic and RF amplitude characteristic at the time of direct modulation satisfying a predetermined extinction ratio and eye mask specification. A method for selecting measurement points for wavelength characteristics, optical output power characteristics, and RF amplitude characteristics. A first means configured to generate a light output, and a second means for automatically controlling the driving current or the light output power of the light emitting element constituting the first means to be kept at a given target value. Means, a third means for automatically controlling the element temperature of the light emitting element constituting the first means to maintain a given target value, and the RF amplitude of the light emitting element constituting the first means And a light source unit for direct modulation optical communication having a fourth means for automatically controlling to maintain a given target value,
To the light emitting elements constituting the first means, at least one value of the optical output wavelength for the drive current and device temperature direct modulation time satisfying the predetermined extinction ratio and eye mask requirement, Oh Rui of these three at least one parameter value for determining the relationship, the predetermined at least one value of the extinction ratio and optical output power for the drive current and device temperature direct modulation time satisfying the eye mask requirement, Oh Rui of these three related at least one parameter value determining, at least to determine the predetermined extinction ratio and at least one value of the RF amplitude for the drive current and device temperature direct modulation time satisfying the eye mask requirement, Oh Rui of these three related Fifth means for storing one parameter value;
A drive current, element temperature, and light output wavelength at the time of direct modulation satisfying a predetermined extinction ratio of the light emitting element and an eye mask specification determined by at least one value for the light emitting element stored in the fifth means Both the light output wavelength and the light output power of the light emitting element from the relationship and the relationship between the drive current, the element temperature and the light output power during direct modulation satisfying the predetermined extinction ratio and eye mask specification of the light emitting element. Determines the driving current or optical output power and element temperature at which the value of the light emitting element is separately designated, and the driving current and the element when the driving current fluctuates during direct modulation satisfying the predetermined extinction ratio and eye mask specification of the light emitting element A sixth means for determining the determined drive current or optical output power and the RF amplitude at the element temperature from the relationship between the temperature and the RF amplitude;
The driving current or optical output power of the light emitting element, the element temperature and the RF amplitude determined by the sixth means are the target values for the light emitting element in the second means, third means and fourth means, respectively. in direct modulation type optical communication light source unit Ru provided as a predetermined extinction ratio and direct modulation at the optical output that satisfies the eye mask requirement of the light emitting device constituting the first means to be stored in the fifth means A method for selecting measurement points (drive current, element temperature) of wavelength characteristics, optical output power characteristics and RF amplitude characteristics,
A first step of inputting an operation range (i ₁ ≦ i ≦ i ₂ ) of a separately designated drive current i and an operation range (T ₁ ≦ T ≦ T ₂ ) of the element temperature T;
Using an arbitrary value of q (q is a ratio coordinate of an internal dividing point of the operating range of the element temperature T of the light emitting element, and a real number satisfying 0 <q <1), the operation at the specified element temperature T is performed. The range (T ₁ ≦ T ≦ T ₂ ) is internally divided by q: 1-q and 1-q: q to obtain element temperatures T _s1 and T _s2 at the internal dividing points, from which a predetermined value of the light emitting element is obtained. Minimum value of approximation error between the optical output wavelength characteristic with respect to the element temperature during direct modulation that satisfies the extinction ratio and the eye mask specification, and the optical output wavelength characteristic approximated by a linear function of the element temperature | δλ ₀ | _{T = T1 or T2} and the maximum value | δλ ₀ | _{T = (T1 + T2) / 2} and determine the value of q so that they are equal to each other, or from this, the predetermined extinction ratio and eye mask definition of the light emitting element are determined. Nearly satisfactory optical output power characteristics with respect to element temperature during direct modulation and optical output power characteristics approximated by a linear function of element temperature The minimum value | δP ₀ | _{T = T1 or T2} and the maximum value | δP ₀ | _{T = (T1 + T2) / 2} are determined, and the value of q is determined so that they are equal, or Minimum value of approximation error between RF amplitude characteristic with respect to element temperature at the time of direct modulation satisfying a predetermined extinction ratio and eye mask specification of the light emitting element and RF amplitude characteristic approximated by a linear function of element temperature | δi _RF0 | _{T = T1 or T2} and the maximum value | δi _RF0 | _{T = (T1 + T2) / 2} is determined, the q value is determined so that they are equal, and the element temperature at this time is taken as the measurement point. A fifth step of determining T _s1 and T _s2 as element temperatures at the measurement points;
A measuring point is a driving current that internally divides the operating range (i ₁ ≦ i ≦ i ₂ ) of the designated driving current i by q: 1-q and 1-q: q using the determined q value. A sixth step of determining as drive currents i _s1 and i _s2 in
Of the four measurement points (i _s1 , T _s1 ), (i _s1 , T _s2 ), (i _s2 , T _s1 ), (i _s2 , T _s2 ) composed of the determined value combinations, any 3 And a fourth process of selecting a point as a measurement point of the optical output wavelength characteristic, optical output power characteristic and RF amplitude characteristic at the time of direct modulation satisfying a predetermined extinction ratio and eye mask specification. A method for selecting measurement points for wavelength characteristics, optical output power characteristics, and RF amplitude characteristics. A first means configured to generate a light output, and a second means for automatically controlling the driving current or the light output power of the light emitting element constituting the first means to be kept at a given target value. Means, a third means for automatically controlling the element temperature of the light emitting element constituting the first means to maintain a given target value, and the RF amplitude of the light emitting element constituting the first means And a light source unit for direct modulation optical communication having a fourth means for automatically controlling to maintain a given target value,
To the light emitting elements constituting the first means, at least one value of the optical output wavelength for the drive current and device temperature direct modulation time satisfying the predetermined extinction ratio and eye mask requirement, Oh Rui of these three at least one parameter value for determining the relationship, the predetermined at least one value of the extinction ratio and optical output power for the drive current and device temperature direct modulation time satisfying the eye mask requirement, Oh Rui of these three related at least one parameter value determining, at least to determine the predetermined extinction ratio and at least one value of the RF amplitude for the drive current and device temperature direct modulation time satisfying the eye mask requirement, Oh Rui of these three related Fifth means for storing one parameter value;
The drive current of the light emitting element constituting the first means is monitored, and it is determined whether or not it is within an allowable fluctuation range specified separately. If not within the allowable fluctuation range, the fifth means From the relationship between the drive current, the element temperature, and the optical output power at the time of direct modulation satisfying a predetermined extinction ratio of the light emitting element and an eye mask defined by at least one value for the stored light emitting element, the light emitting element A predetermined extinction ratio of the light-emitting element determined by at least one value for the light-emitting element stored in the fifth means by predicting a relationship between the drive current, the element temperature, and the optical output power when the drive current fluctuates and the seventh to predict the relationship between the drive current and device temperature and the RF amplitude of the direct modulation time, the relationship between the drive current and device temperature and the RF amplitude during the driving current fluctuation of the light emitting element to satisfy the eye mask requirement And means,
A drive current, element temperature, and light output wavelength at the time of direct modulation satisfying a predetermined extinction ratio and eye mask definition of the light emitting element, which are determined by at least one value for the light emitting element stored in the fifth means And the relationship between the drive current, the device temperature, and the optical output power when the drive current fluctuates during direct modulation that satisfies the predetermined extinction ratio and eye mask specification of the light emitting device predicted by the seventh means The latest driving current or optical output power in which both the optical output wavelength and optical output power during direct modulation satisfying a predetermined extinction ratio and eye mask regulations when the driving current of the light emitting element varies are separately specified values and thereby predicting the latest device temperature, put in driving current fluctuation of direct modulation time satisfying the predetermined extinction ratio and eye mask requirement of the expected light emitting element by the seventh means From the relationship between the drive current and device temperature and the RF amplitude, and a eighth means for predicting the latest RF amplitude in the latest drive current or optical output power and the latest device temperature,
The latest driving current or optical output power of the light emitting element predicted by the eighth means, the latest element temperature, and the latest RF amplitude are respectively obtained in the second means, the third means, and the fourth means. in direct modulation type optical communication light source unit Ru provided as a new target value for the light emitting element, predetermined extinction ratio of the light emitting device constituting the first means to be stored in the fifth means and the eye mask requirement A method of selecting measurement points (drive current, element temperature) for satisfying optical output wavelength characteristics, optical output power characteristics, and RF amplitude characteristics during direct modulation,
A first step of inputting an operation range (i ₁ ≦ i ≦ i ₂ ) of a separately designated drive current i and an operation range (T ₁ ≦ T ≦ T ₂ ) of the element temperature T;
Using an arbitrary value of p (p is a ratio coordinate of the internal dividing point of the operating range of the driving current i of the light emitting element, and a real number satisfying 0 <p <1), the operation of the designated driving current i The range (i ₁ ≦ i ≦ i ₂ ) is internally divided by p: 1-p and 1-p: p to determine drive currents i _s1 and i _s2 at the internal dividing points, and from this, a predetermined value of the light emitting element is determined. Minimum value of the approximation error between the optical output wavelength characteristic with respect to the driving current during direct modulation that satisfies the extinction ratio and the eye mask specification, and the optical output wavelength characteristic approximated by a linear function of the driving current | δλ ₀ | _{i = i1 or i2} and the maximum value | δλ ₀ | _{i = (i1 + i2) / 2} , and determine the value of p so that they are equal to each other, or from this, a predetermined extinction ratio and eye mask definition of the light emitting element Nearly satisfied optical output power characteristics with respect to drive current during direct modulation and optical output power characteristics approximated by a linear function of drive current The minimum value | δP ₀ | _{i = i1 or i2} and the maximum value | δP ₀ | _{i = (i1 + i2) / 2} of the similar error are obtained, and the value of p is determined so that they are equal, or from this Minimum value of approximation error between RF amplitude characteristic with respect to drive current during direct modulation satisfying predetermined extinction ratio and eye mask definition of light emitting element and RF amplitude characteristic approximated by linear function of drive current | δi _RF0 | _{i = i1 or i2} and the maximum value | δi _RF0 | _{i = (i1 + i2) / 2} are determined, and the value of p is determined so that they are equal. a second step of determining i _s1 and i _s2 as drive currents at the measurement points;
A measuring point is an element temperature at which the operating range of the specified element temperature T (T ₁ ≦ T ≦ T ₂ ) is internally divided by p: 1−p and 1−p: p using the determined value of p. A third step of determining as element temperatures T _s1 and T _s2 at
Of the four measurement points (i _s1 , T _s1 ), (i _s1 , T _s2 ), (i _s2 , T _s1 ), (i _s2 , T _s2 ) composed of the determined value combinations, any 3 And a fourth process of selecting a point as a measurement point of the optical output wavelength characteristic, optical output power characteristic and RF amplitude characteristic at the time of direct modulation satisfying a predetermined extinction ratio and eye mask specification. A method for selecting measurement points for wavelength characteristics, optical output power characteristics, and RF amplitude characteristics. A first means configured to generate a light output, and a second means for automatically controlling the driving current or the light output power of the light emitting element constituting the first means to be kept at a given target value. Means, a third means for automatically controlling the element temperature of the light emitting element constituting the first means to maintain a given target value, and the RF amplitude of the light emitting element constituting the first means And a light source unit for direct modulation optical communication having a fourth means for automatically controlling to maintain a given target value,
To the light emitting elements constituting the first means, at least one value of the optical output wavelength for the drive current and device temperature direct modulation time satisfying the predetermined extinction ratio and eye mask requirement, Oh Rui of these three at least one parameter value for determining the relationship, the predetermined at least one value of the extinction ratio and optical output power for the drive current and device temperature direct modulation time satisfying the eye mask requirement, Oh Rui of these three related at least one parameter value determining, at least to determine the predetermined extinction ratio and at least one value of the RF amplitude for the drive current and device temperature direct modulation time satisfying the eye mask requirement, Oh Rui of these three related Fifth means for storing one parameter value;
The drive current of the light emitting element constituting the first means is monitored, and it is determined whether or not it is within an allowable fluctuation range specified separately. If not within the allowable fluctuation range, the fifth means From the relationship between the drive current, the element temperature, and the optical output power at the time of direct modulation satisfying a predetermined extinction ratio of the light emitting element and an eye mask defined by at least one value for the stored light emitting element, the light emitting element A predetermined extinction ratio of the light-emitting element determined by at least one value for the light-emitting element stored in the fifth means by predicting a relationship between the drive current, the element temperature, and the optical output power when the drive current fluctuates and the seventh to predict the relationship between the drive current and device temperature and the RF amplitude of the direct modulation time, the relationship between the drive current and device temperature and the RF amplitude during the driving current fluctuation of the light emitting element to satisfy the eye mask requirement And means,
A drive current, element temperature, and light output wavelength at the time of direct modulation satisfying a predetermined extinction ratio and eye mask definition of the light emitting element, which are determined by at least one value for the light emitting element stored in the fifth means And the relationship between the drive current, the device temperature, and the optical output power when the drive current fluctuates during direct modulation that satisfies the predetermined extinction ratio and eye mask specification of the light emitting device predicted by the seventh means The latest driving current or optical output power in which both the optical output wavelength and optical output power during direct modulation satisfying a predetermined extinction ratio and eye mask regulations when the driving current of the light emitting element varies are separately specified values and thereby predicting the latest device temperature, put in driving current fluctuation of direct modulation time satisfying the predetermined extinction ratio and eye mask requirement of the expected light emitting element by the seventh means From the relationship between the drive current and device temperature and the RF amplitude, and a eighth means for predicting the latest RF amplitude in the latest drive current or optical output power and the latest device temperature,
The latest driving current or optical output power of the light emitting element predicted by the eighth means, the latest element temperature, and the latest RF amplitude are respectively obtained in the second means, the third means, and the fourth means. in direct modulation type optical communication light source unit Ru provided as a new target value for the light emitting element, predetermined extinction ratio of the light emitting device constituting the first means to be stored in the fifth means and the eye mask requirement A method of selecting measurement points (drive current, element temperature) for satisfying optical output wavelength characteristics, optical output power characteristics, and RF amplitude characteristics during direct modulation,
A first step of inputting an operation range (i ₁ ≦ i ≦ i ₂ ) of a separately designated drive current i and an operation range (T ₁ ≦ T ≦ T ₂ ) of the element temperature T;
Using an arbitrary value of q (q is a ratio coordinate of an internal dividing point of the operating range of the element temperature T of the light emitting element, and a real number satisfying 0 <q <1), the operation at the specified element temperature T is performed. The range (T ₁ ≦ T ≦ T ₂ ) is internally divided by q: 1-q and 1-q: q to obtain element temperatures T _s1 and T _s2 at the internal dividing points, from which a predetermined value of the light emitting element is obtained. Minimum value of approximation error between the optical output wavelength characteristic with respect to the element temperature during direct modulation that satisfies the extinction ratio and the eye mask specification, and the optical output wavelength characteristic approximated by a linear function of the element temperature | δλ ₀ | _{T = T1 or T2} and the maximum value | δλ ₀ | _{T = (T1 + T2) / 2} and determine the value of q so that they are equal to each other, or from this, the predetermined extinction ratio and eye mask definition of the light emitting element are determined. Nearly satisfactory optical output power characteristics with respect to element temperature during direct modulation and optical output power characteristics approximated by a linear function of element temperature The minimum value | δP ₀ | _{T = T1 or T2} and the maximum value | δP ₀ | _{T = (T1 + T2) / 2} are determined, and the value of q is determined so that they are equal, or Minimum value of approximation error between RF amplitude characteristic with respect to element temperature at the time of direct modulation satisfying a predetermined extinction ratio and eye mask specification of the light emitting element and RF amplitude characteristic approximated by a linear function of element temperature | δi _RF0 | _{T = T1 or T2} and the maximum value | δi _RF0 | _{T = (T1 + T2) / 2} is determined, the q value is determined so that they are equal, and the element temperature at this time is taken as the measurement point. A fifth step of determining T _s1 and T _s2 as element temperatures at the measurement points;
A measuring point is a driving current that internally divides the operating range (i ₁ ≦ i ≦ i ₂ ) of the designated driving current i by q: 1-q and 1-q: q using the determined q value. A sixth step of determining as drive currents i _s1 and i _s2 in
Of the four measurement points (i _s1 , T _s1 ), (i _s1 , T _s2 ), (i _s2 , T _s1 ), (i _s2 , T _s2 ) composed of the determined value combinations, any 3 And a fourth process of selecting a point as a measurement point of the optical output wavelength characteristic, optical output power characteristic and RF amplitude characteristic at the time of direct modulation satisfying a predetermined extinction ratio and eye mask specification. A method for selecting measurement points for wavelength characteristics, optical output power characteristics, and RF amplitude characteristics. In the selection method of the measurement point of the optical output wavelength characteristic, optical output power characteristic, and RF amplitude characteristic in any one of Claims 1 thru | or 4,
A ninth means for storing the latest values of the target values respectively given to the second means, the third means, and the fourth means;
When using the value stored in the ninth means such as at the time of warm start, the latest value of the target value for the second means, the third means and the fourth means of the light emitting element is set. Read out from the ninth means and give as target values in the second means, third means and fourth means, respectively, the measurement points of the optical output wavelength characteristic, optical output power characteristic and RF amplitude characteristic Selection method . In the selection method of the measurement point of the optical output wavelength characteristic, the optical output power characteristic, and the RF amplitude characteristic according to any one of claims 1 to 5,
The light output generated by the light emitting element constituting the first means is monitored, and the light output wavelength range and the light output power range specified separately for the light output wavelength and / or the light output power of the light output. A method of selecting measurement points for optical output wavelength characteristics, optical output power characteristics, and RF amplitude characteristics, comprising: a tenth means for comparing and determining whether or not the optical output wavelength characteristics are present ; The first means configured to include a plurality of light emitting elements and generate a plurality of light outputs, and the driving current or the light output power of each light emitting element constituting the first means is maintained at a target value given to each. A second means for automatically controlling, a third means for automatically controlling the element temperature of each light-emitting element constituting the first means to maintain a target value given thereto, A light source unit for direct modulation optical communication having a fourth means for automatically controlling the RF amplitude of each light emitting element constituting the first means so as to maintain a target value given to each;
For each light emitting device constituting the first means, at least one value of the optical output wavelength for the drive current and device temperature direct modulation time satisfying the predetermined extinction ratio and eye mask requirement, Oh Rui these three at least one parameter value and at least one value of the optical output power for a given extinction ratio and the drive current and device temperature of the direct modulation time satisfying the eye mask requirement to determine the relationship, Oh Rui these three relationships at least one parameter value and at least one value of the RF amplitude for a given extinction ratio and the drive current and device temperature of the direct modulation time satisfying the eye mask requirement determining, the Oh Rui determining these three relationships Fifth means for storing at least one parameter value;
Driving current, element temperature, and light output during direct modulation satisfying a predetermined extinction ratio and eye mask definition for each light emitting element determined by at least one value for each light emitting element stored in the fifth means The light output wavelength of each light emitting element from the relationship between the wavelength and the relationship between the drive current, element temperature, and light output power during direct modulation that satisfies the predetermined extinction ratio and eye mask specification for each light emitting element Driving current or optical output power and device temperature at which both the optical output power and the optical output power are separately specified, and driving at the time of direct modulation satisfying a predetermined extinction ratio and eye mask specification for each light emitting device A sixth means for determining the determined drive current or optical output power and the RF amplitude at the element temperature from the relationship between the drive current at the time of current fluctuation, the element temperature, and the RF amplitude;
The driving current or optical output power, element temperature, and RF amplitude for each light emitting element determined by the sixth means are set to the light emitting elements in the second means, third means, and fourth means, respectively. in direct modulation type optical communication light source unit Ru provided as a target value for a predetermined extinction ratio of each light emitting device constituting the first means to be stored in the fifth means and the direct modulation satisfying the eye mask requirement A method of selecting measurement points (driving current, element temperature) of optical output wavelength characteristics, optical output power characteristics and RF amplitude characteristics at the time,
A first step of inputting an operation range (i ₁ ≦ i ≦ i ₂ ) of a separately designated drive current i and an operation range (T ₁ ≦ T ≦ T ₂ ) of the element temperature T of each of the light emitting elements;
An arbitrary value of p (p is a ratio coordinate of an internal dividing point of the operating range of the driving current i of each light emitting element, and a real number satisfying 0 <p <1) is used to specify the specified value of each light emitting element. The operating range (i ₁ ≦ i ≦ i ₂ ) of the driving current i is internally divided by p: 1-p and 1-p: p to obtain the driving currents i _s1 and i _s2 at the internal dividing point for each light emitting element, As a result, the approximate error between the optical output wavelength characteristic with respect to the drive current during direct modulation that satisfies the predetermined extinction ratio and eye mask specification of each light emitting element and the optical output wavelength characteristic approximated by a linear function of the drive current The minimum value | δλ ₀ | _{i = i1 or i2} and the maximum value | δλ ₀ | _{i = (i1 + i2) / 2} are obtained, and the value of p is determined so that they are equal to each other. Approximate the optical output power characteristics with respect to the drive current during direct modulation that satisfies the specified extinction ratio and eye mask specification, and a linear function of the drive current The minimum value | δP ₀ | _{i = i1 or i2} and the maximum value | δP ₀ | _{i = (i1 + i2) / 2} are obtained and the value of p is set so that these are equal. Or an amplitude amplitude characteristic approximated by a linear function of the driving current, and an RF amplitude characteristic approximated by a linear function of the driving current, which satisfies the predetermined extinction ratio and eye mask specification of each light emitting element. Approximate error minimum value | δi _RF0 | _{i = i1 or i2} and maximum value | δi _RF0 | _{i = (i1 + i2) / 2} are determined, and the value of p is determined so that they are equal to each other. A second step of determining the drive currents i _s1 and i _s2 as the drive current at the measurement point for each light-emitting element by using the internal dividing point for each element as the measurement point;
An element that internally divides the operating range (T ₁ ≦ T ≦ T ₂ ) of the specified element temperature T of each light emitting element by p: 1-p and 1-p: p using the determined value of p A third step of determining the temperature as the element temperature T _s1 and T _{s2 at} the measurement point for each light emitting element;
Of the four measurement points (i _s1 , T _s1 ), (i _s1 , T _s2 ), (i _s2 , T _s1 ), (i _s2 , T _s2 ) for each light-emitting element comprising the combination of the determined values. Among them, a fourth process of selecting any three points as measurement points for optical output wavelength characteristics, optical output power characteristics, and RF amplitude characteristics at the time of direct modulation satisfying a predetermined extinction ratio and eye mask specification is included. A method of selecting measurement points for characteristic optical output wavelength characteristics, optical output power characteristics, and RF amplitude characteristics. The first means configured to include a plurality of light emitting elements and generate a plurality of light outputs, and the driving current or the light output power of each light emitting element constituting the first means is maintained at a target value given to each. A second means for automatically controlling, a third means for automatically controlling the element temperature of each light-emitting element constituting the first means to maintain a target value given thereto, A light source unit for direct modulation optical communication having a fourth means for automatically controlling the RF amplitude of each light emitting element constituting the first means so as to maintain a target value given to each;
For each light emitting device constituting the first means, at least one value of the optical output wavelength for the drive current and device temperature direct modulation time satisfying the predetermined extinction ratio and eye mask requirement, Oh Rui these three at least one parameter value and at least one value of the optical output power for a given extinction ratio and the drive current and device temperature of the direct modulation time satisfying the eye mask requirement to determine the relationship, Oh Rui these three relationships at least one parameter value and at least one value of the RF amplitude for a given extinction ratio and the drive current and device temperature of the direct modulation time satisfying the eye mask requirement determining, the Oh Rui determining these three relationships Fifth means for storing at least one parameter value;
Driving current, element temperature, and light output during direct modulation satisfying a predetermined extinction ratio and eye mask definition for each light emitting element determined by at least one value for each light emitting element stored in the fifth means The light output wavelength of each light emitting element from the relationship between the wavelength and the relationship between the drive current, element temperature, and light output power during direct modulation that satisfies the predetermined extinction ratio and eye mask specification for each light emitting element Driving current or optical output power and device temperature at which both the optical output power and the optical output power are separately specified, and driving at the time of direct modulation satisfying a predetermined extinction ratio and eye mask specification for each light emitting device A sixth means for determining the determined drive current or optical output power and the RF amplitude at the element temperature from the relationship between the drive current at the time of current fluctuation, the element temperature, and the RF amplitude;
The driving current or optical output power, element temperature, and RF amplitude for each light emitting element determined by the sixth means are set to the light emitting elements in the second means, third means, and fourth means, respectively. in direct modulation type optical communication light source unit Ru provided as a target value for a predetermined extinction ratio of each light emitting device constituting the first means to be stored in the fifth means and the direct modulation satisfying the eye mask requirement A method of selecting measurement points (driving current, element temperature) of optical output wavelength characteristics, optical output power characteristics and RF amplitude characteristics at the time,
A first step of inputting an operation range (i ₁ ≦ i ≦ i ₂ ) of a separately designated drive current i and an operation range (T ₁ ≦ T ≦ T ₂ ) of the element temperature T of each of the light emitting elements;
An arbitrary value of q (q is a ratio coordinate of an internal dividing point of the operating range of the element temperature T of each light emitting element, and a real number satisfying 0 <q <1) is used to specify the specified value of each light emitting element. The operating range (T ₁ ≦ T ≦ T ₂ ) of the element temperature T is internally divided by q: 1-q and 1-q: q to obtain element temperatures T _s1 and T _s2 at the internal dividing point for each light emitting element, As a result, the approximate error between the light output wavelength characteristic with respect to the element temperature during direct modulation that satisfies the predetermined extinction ratio and eye mask specification of each light emitting element, and the light output wavelength characteristic approximated by a linear function of the element temperature. The minimum value | δλ ₀ | _{T = T1 or T2} and the maximum value | δλ ₀ | _{T = (T1 + T2) / 2} are obtained, and the value of q is determined so that they are equal to each other. Approximate the optical output power characteristics with respect to the element temperature during direct modulation that satisfies the specified extinction ratio and eye mask specification, and a linear function of the element temperature The minimum value of the approximation error with respect to the optical output power characteristics thus determined | δP ₀ | _{T = T1 or T2} and the maximum value | δP ₀ | _{T = (T1 + T2) / 2,} and the value of q so that these are equal Or an RF amplitude characteristic with respect to the element temperature at the time of direct modulation that satisfies the predetermined extinction ratio and eye mask definition of each light emitting element, and an RF amplitude characteristic approximated by a linear function of the element temperature. Approximate error minimum value | δi _RF0 | _{T = T1 or T2} and maximum value | δi _RF0 | _{T = (T1 + T2) / 2} are determined, and the value of q is determined so that they are equal, and light emission at this time A fifth step of determining the element temperature T _s1 and T _s2 as the element temperature at the measurement point for each light emitting element by using the internal dividing point for each element as the measurement point;
Driving that divides the operating range (i ₁ ≤ i ≤ i ₂ ) of the designated driving current i of each light emitting element into q: 1-q and 1-q: q using the determined q value. A sixth step of determining the current as the drive currents i _s1 and i _{s2 at} the measurement point for each light emitting element;
Of the four measurement points (i _s1 , T _s1 ), (i _s1 , T _s2 ), (i _s2 , T _s1 ), (i _s2 , T _s2 ) for each light-emitting element comprising the combination of the determined values. Among them, a fourth process of selecting any three points as measurement points for optical output wavelength characteristics, optical output power characteristics, and RF amplitude characteristics at the time of direct modulation satisfying a predetermined extinction ratio and eye mask specification is included. A method of selecting measurement points for characteristic optical output wavelength characteristics, optical output power characteristics, and RF amplitude characteristics. The first means configured to include a plurality of light emitting elements and generate a plurality of light outputs, and the driving current or the light output power of each light emitting element constituting the first means is maintained at a target value given to each. A second means for automatically controlling, a third means for automatically controlling the element temperature of each light-emitting element constituting the first means to maintain a target value given thereto, A light source unit for direct modulation optical communication having a fourth means for automatically controlling the RF amplitude of each light emitting element constituting the first means so as to maintain a target value given to each;
For each light emitting device constituting the first means, at least one value of the optical output wavelength for the drive current and device temperature direct modulation time satisfying the predetermined extinction ratio and eye mask requirement, Oh Rui these three at least one parameter value and at least one value of the optical output power for a given extinction ratio and the drive current and device temperature of the direct modulation time satisfying the eye mask requirement to determine the relationship, Oh Rui these three relationships at least one parameter value and at least one value of the RF amplitude for a given extinction ratio and the drive current and device temperature of the direct modulation time satisfying the eye mask requirement determining, the Oh Rui determining these three relationships Fifth means for storing at least one parameter value;
The drive current of each light emitting element constituting the first means is monitored, and it is determined whether or not the light emitting element is within an allowable fluctuation range separately designated for each light emitting element, and the light emitting element that is not within the allowable fluctuation range For the above, the drive current and element temperature during direct modulation satisfying a predetermined extinction ratio and eye mask definition of the light emitting element, which are determined by at least one value for the light emitting element stored in the fifth means, At least one value for the light emitting element stored in the fifth means is predicted from the relationship with the light output power by predicting the relationship between the drive current, the element temperature and the light output power when the drive current of the light emitting element varies. the determined from the relationship between the drive current and device temperature and the RF amplitude of the direct modulation time satisfying the predetermined extinction ratio and eye mask requirement of the light emitting element, the drive current during the drive current fluctuation of the light emitting element and the element temperature A seventh means for predicting the relationship between the F amplitude,
For light-emitting elements that are not within the allowable variation range, the light-emitting elements that are determined by at least one value for the light-emitting elements stored in the fifth means directly satisfy the predetermined extinction ratio and eye mask specification of the light-emitting elements. The relationship between the drive current at the time of modulation, the element temperature, and the light output wavelength, and the fluctuation of the drive current at the time of direct modulation that satisfies the predetermined extinction ratio and eye mask specification of the light emitting element predicted by the seventh means Based on the relationship between the drive current, element temperature, and optical output power, both the optical output wavelength and optical output power during direct modulation that satisfy the specified extinction ratio and eye mask specification when the drive current of the light emitting element fluctuates are emitted. with predicting the latest drive current or optical output power and the latest device temperature to be the value that is specified separately for each element, predetermined extinction ratio and a predicted light emitting element by the seventh means The latest driving current or optical output power and the latest RF amplitude at the latest element temperature are predicted from the relationship between the driving current, the element temperature, and the RF amplitude when the driving current fluctuates during direct modulation that satisfies the mask specification. With the means of
The latest drive current or optical output power, the latest element temperature, and the latest RF amplitude for each light emitting element that are not within the allowable variation range predicted by the eighth means are respectively set as the second means, given the respective light emitting elements constituting the unit, and fourth means direct modulation type optical communication light source unit Ru provided as a new target value for the light emitting element in the, said first means is stored in the fifth means A method of selecting measurement points (drive current, element temperature) of optical output wavelength characteristics, optical output power characteristics and RF amplitude characteristics at the time of direct modulation satisfying the extinction ratio and eye mask specification,
A first step of inputting an operation range (i ₁ ≦ i ≦ i ₂ ) of a separately designated drive current i and an operation range (T ₁ ≦ T ≦ T ₂ ) of the element temperature T of each of the light emitting elements;
An arbitrary value of p (p is a ratio coordinate of an internal dividing point of the operating range of the driving current i of each light emitting element, and a real number satisfying 0 <p <1) is used to specify the specified value of each light emitting element. The operating range (i ₁ ≦ i ≦ i ₂ ) of the driving current i is internally divided by p: 1-p and 1-p: p to obtain the driving currents i _s1 and i _s2 at the internal dividing point for each light emitting element, As a result, the approximate error between the optical output wavelength characteristic with respect to the drive current during direct modulation that satisfies the predetermined extinction ratio and eye mask specification of each light emitting element and the optical output wavelength characteristic approximated by a linear function of the drive current The minimum value | δλ ₀ | _{i = i1 or i2} and the maximum value | δλ ₀ | _{i = (i1 + i2) / 2} are obtained, and the value of p is determined so that they are equal to each other. Approximate the optical output power characteristics with respect to the drive current during direct modulation that satisfies the specified extinction ratio and eye mask specification, and a linear function of the drive current The minimum value | δP ₀ | _{i = i1 or i2} and the maximum value | δP ₀ | _{i = (i1 + i2) / 2} are obtained and the value of p is set so that these are equal. Or an amplitude amplitude characteristic approximated by a linear function of the driving current, and an RF amplitude characteristic approximated by a linear function of the driving current, which satisfies the predetermined extinction ratio and eye mask specification of each light emitting element. Approximate error minimum value | δi _RF0 | _{i = i1 or i2} and maximum value | δi _RF0 | _{i = (i1 + i2) / 2} are determined, and the value of p is determined so that they are equal to each other. A second step of determining the drive currents i _s1 and i _s2 as the drive current at the measurement point for each light-emitting element by using the internal dividing point for each element as the measurement point;
An element that internally divides the operating range (T ₁ ≦ T ≦ T ₂ ) of the specified element temperature T of each light emitting element by p: 1-p and 1-p: p using the determined value of p A third step of determining the temperature as the element temperature T _s1 and T _{s2 at} the measurement point for each light emitting element;
Of the four measurement points (i _s1 , T _s1 ), (i _s1 , T _s2 ), (i _s2 , T _s1 ), (i _s2 , T _s2 ) for each light-emitting element comprising the combination of the determined values. Among them, a fourth process of selecting any three points as measurement points for optical output wavelength characteristics, optical output power characteristics, and RF amplitude characteristics at the time of direct modulation satisfying a predetermined extinction ratio and eye mask specification is included. A method of selecting measurement points for characteristic optical output wavelength characteristics, optical output power characteristics, and RF amplitude characteristics. The first means configured to include a plurality of light emitting elements and generate a plurality of light outputs, and the driving current or the light output power of each light emitting element constituting the first means is maintained at a target value given to each. A second means for automatically controlling, a third means for automatically controlling the element temperature of each light-emitting element constituting the first means to maintain a target value given thereto, A light source unit for direct modulation optical communication having a fourth means for automatically controlling the RF amplitude of each light emitting element constituting the first means so as to maintain a target value given to each;
For each light emitting device constituting the first means, at least one value of the optical output wavelength for the drive current and device temperature direct modulation time satisfying the predetermined extinction ratio and eye mask requirement, Oh Rui these three at least one parameter value and at least one value of the optical output power for a given extinction ratio and the drive current and device temperature of the direct modulation time satisfying the eye mask requirement to determine the relationship, Oh Rui these three relationships at least one parameter value and at least one value of the RF amplitude for a given extinction ratio and the drive current and device temperature of the direct modulation time satisfying the eye mask requirement determining, the Oh Rui determining these three relationships Fifth means for storing at least one parameter value;
The drive current of each light emitting element constituting the first means is monitored, and it is determined whether or not the light emitting element is within an allowable fluctuation range separately designated for each light emitting element, and the light emitting element that is not within the allowable fluctuation range For the above, the drive current and element temperature during direct modulation satisfying a predetermined extinction ratio and eye mask definition of the light emitting element, which are determined by at least one value for the light emitting element stored in the fifth means, At least one value for the light emitting element stored in the fifth means is predicted from the relationship with the light output power by predicting the relationship between the drive current, the element temperature and the light output power when the drive current of the light emitting element varies. the determined from the relationship between the drive current and device temperature and the RF amplitude of the direct modulation time satisfying the predetermined extinction ratio and eye mask requirement of the light emitting element, the drive current during the drive current fluctuation of the light emitting element and the element temperature A seventh means for predicting the relationship between the F amplitude,
For light-emitting elements that are not within the allowable variation range, the light-emitting elements that are determined by at least one value for the light-emitting elements stored in the fifth means directly satisfy the predetermined extinction ratio and eye mask specification of the light-emitting elements. The relationship between the drive current at the time of modulation, the element temperature, and the light output wavelength, and the fluctuation of the drive current at the time of direct modulation that satisfies the predetermined extinction ratio and eye mask specification of the light emitting element predicted by the seventh means Based on the relationship between the drive current, element temperature, and optical output power, both the optical output wavelength and optical output power during direct modulation that satisfy the specified extinction ratio and eye mask specification when the drive current of the light emitting element fluctuates are emitted. with predicting the latest drive current or optical output power and the latest device temperature to be the value that is specified separately for each element, predetermined extinction ratio and a predicted light emitting element by the seventh means The latest driving current or optical output power and the latest RF amplitude at the latest element temperature are predicted from the relationship between the driving current, the element temperature, and the RF amplitude when the driving current fluctuates during direct modulation that satisfies the mask specification. With the means of
The latest drive current or optical output power, the latest element temperature, and the latest RF amplitude for each light emitting element that are not within the allowable variation range predicted by the eighth means are respectively set as the second means, given the respective light emitting elements constituting the unit, and fourth means direct modulation type optical communication light source unit Ru provided as a new target value for the light emitting element in the, said first means is stored in the fifth means A method of selecting measurement points (drive current, element temperature) of optical output wavelength characteristics, optical output power characteristics and RF amplitude characteristics at the time of direct modulation satisfying the extinction ratio and eye mask specification,
A first step of inputting an operation range (i ₁ ≦ i ≦ i ₂ ) of a separately designated drive current i and an operation range (T ₁ ≦ T ≦ T ₂ ) of the element temperature T of each of the light emitting elements;
An arbitrary value of q (q is a ratio coordinate of an internal dividing point of the operating range of the element temperature T of each light emitting element, and a real number satisfying 0 <q <1) is used to specify the specified value of each light emitting element. The operating range (T ₁ ≦ T ≦ T ₂ ) of the element temperature T is internally divided by q: 1-q and 1-q: q to obtain element temperatures T _s1 and T _s2 at the internal dividing point for each light emitting element, As a result, the approximate error between the light output wavelength characteristic with respect to the element temperature during direct modulation that satisfies the predetermined extinction ratio and eye mask specification of each light emitting element, and the light output wavelength characteristic approximated by a linear function of the element temperature. The minimum value | δλ ₀ | _{T = T1 or T2} and the maximum value | δλ ₀ | _{T = (T1 + T2) / 2} are obtained, and the value of q is determined so that they are equal to each other. Approximate the optical output power characteristics with respect to the element temperature during direct modulation that satisfies the specified extinction ratio and eye mask specification, and a linear function of the element temperature The minimum value of the approximation error with respect to the optical output power characteristics thus determined | δP ₀ | _{T = T1 or T2} and the maximum value | δP ₀ | _{T = (T1 + T2) / 2,} and the value of q so that these are equal Or an RF amplitude characteristic with respect to the element temperature at the time of direct modulation that satisfies the predetermined extinction ratio and eye mask definition of each light emitting element, and an RF amplitude characteristic approximated by a linear function of the element temperature. Approximate error minimum value | δi _RF0 | _{T = T1 or T2} and maximum value | δi _RF0 | _{T = (T1 + T2) / 2} are determined, and the value of q is determined so that they are equal, and light emission at this time A fifth step of determining the element temperature T _s1 and T _s2 as the element temperature at the measurement point for each light emitting element by using the internal dividing point for each element as the measurement point;
Driving that divides the operating range (i ₁ ≤ i ≤ i ₂ ) of the designated driving current i of each light emitting element into q: 1-q and 1-q: q using the determined q value. A sixth step of determining the current as the drive currents i _s1 and i _{s2 at} the measurement point for each light emitting element;
Of the four measurement points (i _s1 , T _s1 ), (i _s1 , T _s2 ), (i _s2 , T _s1 ), (i _s2 , T _s2 ) for each light-emitting element comprising the combination of the determined values. Among them, a fourth process of selecting any three points as measurement points for optical output wavelength characteristics, optical output power characteristics, and RF amplitude characteristics at the time of direct modulation satisfying a predetermined extinction ratio and eye mask specification is included. A method of selecting measurement points for characteristic optical output wavelength characteristics, optical output power characteristics, and RF amplitude characteristics. In the selection method of the measurement point of the optical output wavelength characteristic, optical output power characteristic, and RF amplitude characteristic in any one of Claims 7 thru | or 10,
A ninth means for storing the latest values of the target values respectively given to the second means, the third means and the fourth means for each light emitting element;
When using the value stored in the ninth means such as at the time of warm start, the latest value of the target value for the second means, the third means and the fourth means for each light emitting element. Is output from the ninth means and given as a target value for each light emitting element in the second means, the third means, and the fourth means, respectively, and the optical output wavelength characteristic, optical output power characteristic, and RF amplitude How to select characteristic measurement points . The method for selecting measurement points of the optical output wavelength characteristics, optical output power characteristics, and RF amplitude characteristics according to any one of claims 7 to 11,
The light output generated by each light-emitting element constituting the first means is monitored, and the light output wavelength range specified separately for each of the light output wavelength and / or light output power of the light output, and A light output wavelength characteristic, a light output power characteristic, and an RF amplitude, characterized by comprising: a tenth means for comparing and determining for each light emitting element whether or not the light output power range is present, and outputting the result of the comparison and determination How to select characteristic measurement points .

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