JP4761784B2 - Laser module and laser module control method - Google Patents

Description

  The present invention relates to a laser module including a semiconductor laser, a laser module control device, a laser module control method, laser module control data, and an optical communication device.

  A semiconductor laser device equipped with a system called a wavelength locker is known. The wavelength locker acquires the output wavelength of the semiconductor laser device by detecting the output light intensity via the etalon. Further, the wavelength locker uses the output wavelength to control the parameters of the semiconductor laser device so that a desired output wavelength is realized (see, for example, Patent Document 1).

  The etalon has a function of converting the output wavelength of the semiconductor laser device into intensity information. However, since the etalon gives a periodic wavelength peak to the transmitted light, the light transmitted through the etalon may have the same light intensity even at different wavelengths. Hereinafter, the wavelength peak that the etalon gives to the transmitted light is referred to as an etalon peak. In this case, in order to detect the wavelength using the transmitted light of the etalon, it is necessary to control the wavelength of the output light of the semiconductor laser device in advance in a band narrower than the period of the etalon peak.

  By the way, in a general semiconductor laser device with a wavelength locker, the temperature of the semiconductor laser is kept constant by a temperature control device. Also, parameters such as injected current can be controlled with high accuracy. Therefore, the wavelength control of output light is easy.

JP 2001-308444 A

  However, in an external resonant laser device equipped with an etalon capable of electronically controlling the transmission wavelength, components other than the optical system such as an electrode for controlling the etalon are required. As a result, the etalon becomes large and easily affected by external temperature. In addition, since the bonding wire or the like for applying the control potential is connected to the lead of the module package, it becomes a thermal path to the outside.

  For this reason, an external resonant laser device equipped with an etalon capable of electronically controlling the transmission wavelength is easily affected by the outside air temperature. Therefore, a wavelength error larger than the periodicity of the rocker etalon used in the wavelength locker is generated only by controlling the temperature control device and the parameters such as the injection current. As a result, it is difficult to control the wavelength of the output light of the semiconductor laser device in a band narrower than the etalon peak period.

  The present invention relates to a laser module, a laser module control device, a laser module control method, a laser module control data, and a light capable of performing wavelength control of output light in a narrower band than the etalon peak period of an etalon of a wavelength locker An object is to provide a communication device.

Another laser module according to the present invention includes an external resonant laser having a first etalon having a periodic wavelength peak in transmission characteristics and the wavelength peak being changed by an applied electric signal, and a periodic transmission characteristic. A second etalon having a clear wavelength peak and transmitting light output from the external resonance laser, a temperature controller for controlling the temperature of the first etalon and the temperature of the second etalon, and a temperature controller A first temperature detector that is provided at a distance and detects the temperature of the first etalon or a temperature substantially equal to the temperature of the first etalon, and a second temperature that detects the temperature of the second etalon It comprises a detector and a light intensity detector for detecting the intensity of the output light of the external resonance laser , and the second temperature detector is mounted on a temperature control device on which the second etalon is mounted. Is what .

  In another laser module according to the present invention, the temperature of the first etalon or a temperature substantially equal to the temperature of the first etalon is detected by the first temperature detector, and the second temperature detector detects the first temperature. The temperature of the first etalon is detected, the temperature of the first etalon is controlled by the temperature control device, and a periodic wavelength peak is given to the light output from the external resonance laser by the second etalon, and the external resonance type The intensity of the laser output light is detected by the light intensity detection means. In this case, since the temperature of the first etalon is accurately detected, the periodic transmission wavelength peak of the first etalon can be controlled to a desired wavelength. Even when the temperature of the second etalon is controlled, a desired oscillation wavelength is output from the external resonance laser by controlling the electric signal applied to the first etalon using the detection result of the light intensity detection means. be able to. Therefore, wavelength control of the output laser light can be performed in a band narrower than the etalon peak period of the second etalon.

Also, the first etalon and the second etalon, may be mounted on a temperature control device. In this case, the temperature of the first etalon and the second etalon can be controlled by a common temperature control device. Therefore, the configuration of the laser module according to the present invention is simplified.

The first etalon may include liquid crystal, and the refractive index of the liquid crystal may be changed by being supplied with an electric signal. In this case, the transmission wavelength peak of the first etalon can be controlled by the electric signal .

Still another control method of the laser module according to the present invention includes an external resonance type laser including a first etalon having a periodic wavelength peak in transmission characteristics and a wavelength peak changing according to an applied electric signal, A second etalon having a periodic wavelength peak in its characteristics and transmitting light output from the external resonant laser; a temperature controller for controlling the temperature of the first etalon and the temperature of the second etalon; A first temperature detector that is provided apart from the temperature control device and detects a temperature of the first etalon or a temperature substantially equal to the temperature of the first etalon, and a temperature of the second etalon. A second temperature detection unit, the relative relationship between the temperature change of the first etalon and the fluctuation amount of the periodic wavelength peak of the first etalon is known , the first etalon, the second etalon, and Second Degree detecting unit is a control method for a laser module that is mounted on the temperature control device, temperature first temperature detector detects the external cavity laser outputs a desired wavelength at a predetermined ambient temperature A first step in which the temperature control device is controlled so that the temperature of the first etalon is in the case where the external resonant laser is outputting a desired wavelength light at a predetermined outside air temperature. A second step in which an electrical signal applied to the first etalon is applied to the first etalon, and an electrical signal applied to the first etalon so that the peak wavelength of the output light of the external resonance laser becomes a desired wavelength. The temperature of the second etalon when the third step to be controlled and the temperature detected by the second temperature detector is a predetermined outside air temperature and the external resonant laser outputs light of a desired wavelength The temperature change amount of the first etalon so as to cancel out the change in the periodic wavelength peak of the first etalon that occurs in the fourth step and the fourth step in which the temperature control device is controlled to become And a fifth step of controlling the electrical signal applied to the first etalon based on the relative relationship between the electrical signal value applied to the first etalon and the electrical signal value applied to the first etalon.

  In still another control method of the laser module according to the present invention, the first temperature detector detects the first wavelength when the external resonant laser outputs light of a desired wavelength at a predetermined outside temperature. The temperature control device is controlled so that the temperature of the etalon is reached, and an electric signal given to the first etalon in a state where the external resonance laser at a predetermined outside temperature outputs light of a desired wavelength is the first etalon. The electrical signal applied to the first etalon is controlled so that the peak wavelength of the output light of the external resonant laser becomes a desired wavelength, and the temperature detected by the second temperature detector is set at a predetermined outside air temperature. The temperature controller is controlled so as to reach the temperature of the second etalon when the external resonant laser outputs light having a desired wavelength, and the second step generated in the fourth step is performed. Of the electrical signal applied to the first etalon based on the relative relationship between the temperature change amount of the first etalon and the electrical signal value applied to the first etalon so as to cancel out the change in the periodic wavelength peak of the etalon. Control is made. In this case, since the temperature of the first etalon is accurately detected, the periodic transmission wavelength peak of the first etalon can be controlled to a desired wavelength. Also, when controlling the temperature of the second etalon, a desired oscillation wavelength is output from the external resonant laser by controlling the electrical signal applied to the first etalon based on the temperature variation of the first etalon. Can be made. Therefore, even when the temperature dependence of the second etalon is high, the wavelength control of the output laser light can be accurately performed in a band narrower than the etalon peak period of the second etalon.

  The first etalon includes a liquid crystal, and the refractive index of the liquid crystal may be changed by being supplied with an electric signal. In this case, the transmission wavelength peak of the first etalon can be controlled by the electric signal. The third to fifth steps may be performed at an outside air temperature different from the predetermined outside air temperature. Therefore, the wavelength control of the output laser beam can be accurately performed even at an outside air temperature different from the predetermined outside air temperature.

  According to the present invention, the wavelength control of the output laser light can be performed in a band narrower than the etalon peak period of the second etalon.

  Hereinafter, the best mode for carrying out the present invention will be described.

  FIG. 1 is a schematic diagram illustrating an overall configuration of a laser apparatus 100 according to the first embodiment. As shown in FIG. 1, the laser device 100 includes an external resonant laser 10, a power monitor unit 20, a wavelength locker unit 30, a temperature control device 40, and a control unit 50.

  The external resonant laser 10 includes a semiconductor optical amplifier 11, a liquid crystal etalon 12 and a mirror 13. A liquid crystal etalon 12 and a mirror 13 are sequentially arranged behind the semiconductor optical amplifier 11.

  The semiconductor optical amplifier 11 gives a gain to input light having a predetermined effective wavelength band and outputs laser light in accordance with an instruction from the control unit 50. A mirror 15 is provided in front of the semiconductor optical amplifier 11. A phase adjuster 16 is provided at the rear of the semiconductor optical amplifier 11. The refractive index of the phase adjuster 16 changes based on the current supplied from the control unit 50. When the refractive index of the phase adjuster 16 changes, the phase of the peak wavelength of the light transmitted through the phase adjuster 16 changes.

  The liquid crystal etalon 12 is composed of a liquid crystal bandpass filter that transmits light at a predetermined wavelength period. The liquid crystal etalon 12 has a structure in which liquid crystal is sandwiched between two plates. Connected to the liquid crystal etalon 12 is a wire 12 a for giving an electric signal to the liquid crystal of the liquid crystal etalon 12. The wire 12a is connected to an external lead (not shown) of the laser device 100. As the wire 12a, a bonding wire, a ribbon, or the like can be used. Further, the liquid crystal etalon 12 and the external lead may be directly connected.

  The refractive index of the liquid crystal etalon 12 changes based on an electrical signal given from the control unit 50. The etalon peak of the liquid crystal etalon 12 is changed by a change in the refractive index of the liquid crystal etalon 12. The laser module 100 according to this embodiment can output laser light having an n-channel etalon peak wavelength by using the liquid crystal etalon 12. The mirror 13 reflects incident light. The mirror 13 may be a total reflection mirror or a mirror that reflects light in a predetermined wavelength range.

  A beam splitter 14 is disposed in front of the semiconductor optical amplifier 11. The beam splitter 14 transmits a part of the laser light output from the external resonant laser 10 and outputs it to the outside, and reflects a part of the laser light output from the external resonant laser 10 to reflect the power. 20 is given.

  The power monitor unit 20 includes a light detection element 21. The light detection element 21 measures the light intensity of the laser beam given from the beam splitter 14 and gives the measured value to the control unit 50. The control unit 50 controls the gain of the semiconductor optical amplifier 11 based on the measurement value given from the light detection element 21. A part of the laser beam applied to the light detection element 21 is applied to the wavelength locker unit 30.

  The wavelength locker unit 30 includes a rocker etalon 31 and a light detection element 32. The rocker etalon 31 is provided with a part of the laser beam applied to the light detection element 21. The laser beam applied to the rocker etalon 31 is applied to the light detection element 32 as a laser beam having a predetermined wavelength peak. The light detecting element 32 measures the light intensity of the laser beam given from the rocker etalon 31 and gives the measurement result to the control unit 50. The control unit 50 calculates the wavelength of the laser light output from the external resonant laser 10 based on the measurement result given from the light detection element 32. Further, the control unit 50 controls the refractive index of the phase adjuster 16 so that the phase of the peak wavelength of the laser light output from the external resonant laser 10 becomes a desired phase based on the calculation result.

  The external resonance laser 10, the power monitor unit 20, and the wavelength locker unit 30 are disposed on the temperature control device 40. The temperature control device 40 maintains a constant temperature in accordance with instructions from the control unit 50. Thereby, the temperature of the laser module 100 is kept constant, and the wavelength of the laser beam output from the laser module 100 is stabilized. The temperature control device 40 includes a thermistor 41 and a thermistor 42. The thermistor 41 is disposed in the vicinity of the liquid crystal etalon 12. Details will be described later. The thermistor 42 is disposed on the temperature control device 40 and detects the temperature of the temperature control device 40.

  The control unit 50 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and the like. Control data 70 of the laser module 100 is stored in the ROM of the control unit 50. The control unit 50 controls the semiconductor optical amplifier 11, the liquid crystal etalon 12, and the phase adjuster 16 based on the control data 70.

  FIG. 2 is a perspective view showing the positional relationship between the liquid crystal etalon 12 and the thermistor 41. As shown in FIG. 2, the thermistor 41 is disposed on a pedestal 60 provided in the vicinity of the liquid crystal etalon 12. The pedestal 60 is disposed on the temperature control device 40. Further, the height of the pedestal 60 is, for example, about half the height of the liquid crystal etalon 12. Therefore, the thermistor 41 is provided apart from the temperature control device 40.

  The liquid crystal etalon 12 is held in the etalon folder 12b, and is disposed on the temperature control device 40 via the etalon folder 12b. Further, the heat capacity of the liquid crystal etalon 12 is relatively large. Furthermore, the liquid crystal etalon 12 is easily affected by outside air through the wire 12a for signal input and the like. Therefore, since the temperature of the temperature controller 40 and the temperature of the liquid crystal etalon 12 are different, it is difficult to accurately detect the temperature of the liquid crystal etalon 12 by the thermistor 42 on the temperature controller 40.

  The etalon peak of the liquid crystal etalon 12 also depends on the temperature of the liquid crystal etalon 12. Therefore, in order to accurately control the etalon peak of the liquid crystal etalon 12, it is necessary to accurately detect the temperature of the liquid crystal etalon 12.

  In the present embodiment, a pedestal 60 is disposed on the temperature control device 40 to bring the heat transfer state from the temperature control device 40 closer to the state of the liquid crystal etalon 12. Thereby, the temperature of the pedestal 60 is substantially equal to the temperature of the liquid crystal etalon 12. Further, the thermistor 41 is electrically connected to the outside of the laser device 100 through a wire 41a. As a result, the thermistor 41 is affected by the outside air temperature in the same manner as the liquid crystal etalon 12. Therefore, the thermistor 41 disposed on the pedestal 60 can detect a temperature substantially equivalent to that of the liquid crystal etalon 12.

  In addition to the above configuration, it is of course possible to detect the temperature of the liquid crystal etalon 12 by providing a temperature detection element such as a thermistor directly on the liquid crystal etalon 12.

  FIG. 3 is a diagram for explaining the control data 70 of the laser module 100. As shown in FIG. 3, the control data 70 includes the control current value of the semiconductor optical amplifier 11, the control current value of the phase adjuster 16, and the control power value of the liquid crystal etalon 12 when the temperature of the liquid crystal etalon 12 is a predetermined temperature. Pressure, target current values of the light detection elements 21 and 32, and the temperature of the thermistor 41. The voltage value and the current value are set for each channel of the liquid crystal etalon 12.

  Next, a method for creating the control data 70 will be described. First, the outside air temperature of the laser module 100 is kept at a constant temperature. Next, the external resonance laser 10, the power monitor unit 20, and the wavelength locker unit 30 are controlled by the control unit 50 so that the peak wavelength of the laser light output from the beam splitter 14 becomes a desired value. In this case, the control current value of the semiconductor optical amplifier 11, the control current value of the phase adjuster 16, the control voltage value of the liquid crystal etalon 12, the target current value of the light detection elements 21 and 32, and the detection result by the thermistor 41 are Record in ROM. The above operation is performed for each channel of the liquid crystal etalon 12. Control data 70 is created by the above operation.

  Next, a method for controlling the laser module 100 by the control unit 50 will be described. First, the control unit 50 controls the temperature control device 40 so that the temperature of the liquid crystal etalon 12 matches the temperature of the liquid crystal etalon 12 when the control data 70 is created. The temperature of the liquid crystal etalon 12 is detected by the thermistor 41. Next, the control unit 50 controls the semiconductor optical amplifier 11 and the liquid crystal etalon 12 based on the control data 70. Since the temperature of the liquid crystal etalon 12 is set to the temperature when the control data 70 is created, the etalon peak of the liquid crystal etalon 12 is equivalent to the etalon peak of the liquid crystal etalon 12 when the control data 70 is created. Therefore, the peak wavelength of the laser beam output from the laser module 100 can be controlled in a band narrower than the etalon peak period of the rocker etalon 31.

  Next, the control unit 50 controls the refractive index of the phase adjuster 16 based on the detection result of the light detection element 32 so that the peak wavelength of the laser light output from the external resonance laser 10 becomes a desired wavelength. . Thereby, the peak wavelength of the laser beam output from the laser module 100 can be controlled more accurately.

  The control data 70 may be stored in another recording medium, or may be transmitted to the user's recording medium by electronic transmission means. FIG. 4 is a diagram for explaining another recording medium in which the control data 70 is stored. 4A shows a recording medium in which the control data 70 is stored, and FIG. 4B shows a state in which the control data 70 is transmitted to the user's recording medium.

  As shown in FIG. 4A, the control data 70 is stored in the recording medium 71. As the recording medium 71, a portable medium such as a magnetic disk or a CD-ROM can be used. In this case, the control unit 50 reads the control data 70 recorded on the recording medium 71 and controls the laser module 100. Further, as shown in FIG. 4B, the control data 70 may be recorded on a recording medium prepared in advance by the user by electronic transmission means such as the Internet 72.

  In this embodiment, the liquid crystal etalon 12 corresponds to the first etalon, the rocker etalon 31 corresponds to the second etalon, the light detection element 32 corresponds to the light intensity detection means, and the temperature control device 40 corresponds to the first etalon. The thermistor 41 corresponds to the temperature detector or the first temperature detector, and the thermistor 42 corresponds to the second temperature detector.

  Next, the laser module 100a according to the second embodiment will be described. Depending on the temperature dependence of the rocker etalon, when the control of the first embodiment is performed, the wavelength of the etalon peak of the rocker etalon changes. In order to correct this, in this embodiment, the thermistor 42 of FIG. 1 is used to perform control in consideration of the temperature dependence of the rocker etalon.

  The configuration of the laser module 100a is the same as that of the laser module 100. The laser module 100a is different from the laser module 100 in that the control unit 50 controls the semiconductor optical amplifier 11, the liquid crystal etalon 12, the phase adjuster 16, and the light detection elements 21 and 32 based on the control data 70a. is there.

  Since the rocker etalon 31 does not need to be electrically controlled, no wire or the like is provided. Thereby, the influence which rocker etalon 31 receives from outside temperature becomes small. As a result, the temperature of the rocker etalon 31 becomes the same temperature as the thermistor 42 mounted on the temperature control device 40. Therefore, the thermistor 42 can accurately detect the temperature of the rocker etalon 31.

  FIG. 5 is a diagram for explaining the control data 70a. As shown in FIG. 5, the control data 70a includes the control current value of the semiconductor optical amplifier 11, the control current value of the phase adjuster 16, and the control voltage value of the liquid crystal etalon 12 when the temperature of the liquid crystal etalon 12 is a predetermined temperature. , The target current value of the light detection elements 21, 32, the light intensity value detected by the light detection element 21, and the temperature of the thermistors 41, 42. The voltage value, current value, and light intensity value are set for each channel of the liquid crystal etalon 12.

  Next, a method for creating the control data 70a will be described. First, the outside air temperature of the laser module 100a is kept at a constant temperature. Next, the external resonant laser 10, the power monitor unit 20, and the wavelength locker unit 30 are controlled by the control unit 50 so that the peak wavelength and the light intensity of the laser beam output from the beam splitter 14 have predetermined values. In this case, the control current value of the semiconductor optical amplifier 11, the control current value of the phase adjuster 16, the control voltage value of the liquid crystal etalon 12, the target current values of the light detection elements 21 and 32, and the light intensity value detected by the light detection element 21. And the detection results by the thermistors 41 and 42 are recorded in the ROM of the control unit 50. The above operation is performed for each channel of the liquid crystal etalon 12. Control data 70a is created by the above operations.

  Next, a method for controlling the laser module 100a by the control unit 50 will be described. First, the control unit 50 performs control similar to the control method of the laser module 100 according to the first embodiment. Thereafter, the control unit 50 controls the wavelength locker unit 30 by controlling the temperature control device 40 so that the detection result by the thermistor 42 matches the detection result by the thermistor 42 when the control data 70 a is created. In this case, even if the temperature dependence of the rocker etalon 31 is high, the control is performed in a state where the temperature of the rocker etalon 31 is the temperature at which the control data 70 is created. The wavelength does not change. Therefore, in the laser module 100a, the peak wavelength of the laser beam output from the laser module 100a can be controlled more accurately.

  Even if the temperature of the liquid crystal etalon 12 fluctuates from the temperature at the time of creation of the control data 70a by the control of the temperature control device 40, the control unit 50 determines that the light intensity value detected by the light detection element 21 is the light intensity value of the control data 70a. The control voltage of the liquid crystal etalon 12 is controlled to be equal to. This prevents the phase of the peak wavelength of the light output from the laser module 100a from changing.

  In this case, control data 70b including a voltage value to be applied to the liquid crystal etalon 12 can be used in order to cancel the intensity change amount of the laser light output from the laser module 100a. FIG. 6 is a diagram showing the control data 70b. As shown in FIG. 6, the control data 70 b includes a variation amount of the detection intensity of the light detection element 21 and a voltage applied to the liquid crystal etalon 12 in order to cancel the variation amount. Based on the control data 70b, the control unit 50 can control the control voltage of the liquid crystal etalon 12 so as to cancel out fluctuations in light intensity detected by the light detection element 21.

  The control data 70b is obtained by recording the control voltage of the liquid crystal etalon 12 necessary for offsetting the fluctuation of the light intensity detected by the light detection element 21 while changing the temperature of the liquid crystal etalon 12.

  In addition to the above control, the control may be performed by using the ratio between the light intensity of the reflected light reflected by the liquid crystal etalon 12 and the light intensity of the transmitted light transmitted through the liquid crystal etalon 12. For example, a third photodetecting element (not shown) is disposed on the optical path of the light that is given from the mirror 13 to the liquid crystal etalon 12 and is not transmitted through the liquid crystal etalon 12 and reflected.

  When the control is performed using the ratio between the light intensity of the reflected light reflected by the liquid crystal etalon 12 and the light intensity of the transmitted light transmitted through the liquid crystal etalon 12, the light detected by the light detection element 21 when the control data 70a is generated. The ratio between the intensity and the light intensity detected by the third light detecting element is recorded.

  Here, when the etalon peak of the liquid crystal etalon 12 changes, the increase / decrease in the light intensity detected by the light detection element 21 and the increase / decrease in the light intensity detected by the third light detection element are reversed. Accordingly, the ratio of the light intensity detected by the light detection element 21 and the light intensity detected by the third light detection element does not match the ratio at the time of creation of the control data 70a, and the light detected by the light detection element 21 When the increase / decrease in the intensity is opposite to the increase / decrease in the light intensity detected by the third light detection element, the ratio between the light intensity detected by the light detection element 21 and the light intensity detected by the third light detection element is controlled. The electric signal applied to the liquid crystal etalon 12 is controlled so as to be equal to the ratio at the time of creating the data 70a. Thereby, the fluctuation | variation of the peak wavelength of the light which the laser module 100a outputs is prevented.

  In addition, the controller 50 controls the wavelength fluctuation amount of the etalon peak of the liquid crystal etalon 12 based on the temperature change instead of controlling the control voltage of the liquid crystal etalon 12 in order to cancel the fluctuation of the light intensity detected by the light detection element 21. The control voltage of the liquid crystal etalon 12 can be controlled so as to cancel out.

  In this case, the control data 70c including the voltage value applied to the liquid crystal etalon 12 can be used to cancel out the fluctuation amount of the peak wavelength of the output light of the laser module 100a. FIG. 7 is a diagram showing the control data 70c. As shown in FIG. 7, the control data 70 c includes a temperature change amount of the liquid crystal etalon 12 and a control voltage of the liquid crystal etalon 12 necessary to keep the wavelength of the etalon peak of the liquid crystal etalon 12 constant. The control unit 50 controls the control voltage of the liquid crystal etalon 12 based on the control data 70c so that the etalon peak of the liquid crystal etalon 12 is kept constant. Note that the temperature change amount of the liquid crystal etalon 12 can be acquired by the thermistor 41.

  The control data 70c is obtained by recording the control voltage of the liquid crystal etalon 12 necessary to keep the phase of the etalon peak of the liquid crystal etalon 12 constant while changing the temperature of the liquid crystal etalon 12.

  As described above, even when the temperature of the liquid crystal etalon 12 changes due to the influence of the outside air temperature and the temperature dependence of the rocker etalon 31 is high, the laser module 100a can be obtained by using the control data 70a to 70c. It is possible to accurately control the phase of the peak wavelength of the laser beam output from the.

  The control data 70a to 70c may be recorded on a portable medium such as a magnetic disk or a CD-ROM as shown in FIG. The control data 70a to 70c may be recorded on a recording medium prepared in advance by the user by electronic transmission means such as the Internet.

  FIG. 8 is a schematic diagram illustrating an overall configuration of a laser module 100b according to the third embodiment. The laser module 100b is different from the laser module 100 of FIG. 1 in that the external resonant laser 10 is disposed on the temperature control device 40a and the power monitor unit 20 and the wavelength locker unit 30 are disposed on the temperature control device 40b. It is the point where it is arranged.

  The temperature control devices 40a and 40b maintain a constant temperature in accordance with instructions from the control unit 50. The temperature control device 40 a includes a thermistor 43, and the temperature control device 40 b includes a thermistor 44. The thermistor 43 is disposed in the vicinity of the liquid crystal etalon 12. Thereby, the thermistor 43 can accurately detect the temperature of the liquid crystal etalon 12. The thermistor 44 is disposed on the temperature control device 40b and detects the temperature of the temperature control device 40b. Further, the control unit 50 controls the semiconductor optical amplifier 11, the liquid crystal etalon 12, the phase adjuster 16, and the photodetecting elements 21 and 32 based on the control data 70 of FIG.

  Next, a method for controlling the laser module 100b by the control unit 50 will be described. First, the control unit 50 controls the temperature control device 40a so that the temperature of the liquid crystal etalon 12 and the temperature of the liquid crystal etalon 12 when the control data 70 is created match the temperature of the rocker etalon 31 and the control data 70. The temperature control device 40b is controlled so that the temperature of the rocker etalon 31 at the time of creating the same. The temperature of the liquid crystal etalon 12 is detected by the thermistor 43, and the temperature of the rocker etalon 31 is detected by the thermistor 44. Next, the control unit 50 controls the semiconductor optical amplifier 11 and the liquid crystal etalon 12 based on the control data 70. Therefore, the etalon peak of the liquid crystal etalon 12 is the same as the etalon peak of the liquid crystal etalon 12 when the control data 70 is created. In this case, the phase of the peak wavelength of the laser beam output from the laser module 100b can be controlled in a band narrower than the etalon peak period of the rocker etalon 31 without being affected by the outside air temperature.

  In the laser module 100b according to the present embodiment, the temperature of the liquid crystal etalon 12 and the temperature of the rocker etalon 31 can be individually controlled by using the temperature control devices 40a and 40b. Therefore, the wavelength of the etalon peak of the liquid crystal etalon 12 and the wavelength of the etalon peak of the rocker etalon 31 can be individually controlled.

  The effects of the present invention can be obtained if the liquid crystal etalon 12 and the thermistor 43 are mounted on the temperature control device 40a and the rocker etalon 31 and the thermistor 44 are mounted on the temperature control device 40b. Therefore, it is not limited to which temperature control device other members are mounted.

  In the present embodiment, the temperature control device 40a corresponds to the first temperature control device, the temperature control device 40b corresponds to the second temperature control device, the thermistor 43 corresponds to the first temperature detection unit, and the thermistor 44 corresponds to a second temperature detection unit.

It is a schematic diagram which shows the whole structure of the laser apparatus based on 1st Example. It is a perspective view which shows the positional relationship of a liquid crystal etalon and a thermistor. It is a figure explaining control data. It is a figure explaining other recording media in which control data is stored. It is a figure explaining control data. It is a figure which shows control data. It is a figure which shows control data. It is a schematic diagram which shows the whole structure of the laser module which concerns on 3rd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 External resonance type laser 11 Semiconductor optical amplifier 12 Liquid crystal etalon 12a Wire 13 Mirror 16 Phase adjuster 20 Power monitor part 21, 32 Photodetector 30 Wavelength locker part 31 Rocker etalon 40, 40a, 40b Temperature control device 41, 42, 43, 44 Thermistor 50 Control unit 60 Base 70, 70a, 70b, 70c Control data 71 Recording medium 100, 100a Laser module

Claims (7)

An external resonant laser comprising a first etalon having a periodic wavelength peak in transmission characteristics, the wavelength peak being changed by an applied electrical signal;
A second etalon having a periodic wavelength peak in transmission characteristics and transmitting light output from the external resonant laser;
A temperature control device for controlling the temperature of the first etalon and the temperature of the second etalon;
A first temperature detector provided apart from the temperature control device and detecting a temperature of the first etalon or a temperature substantially equal to the temperature of the first etalon;
A second temperature detector for detecting the temperature of the second etalon;
A light intensity detection means for detecting the intensity of the output light of the external resonant laser ,
The laser module, wherein the second temperature detection unit is mounted on a temperature control device on which the second etalon is mounted. The laser module according to claim 1, wherein the first etalon and the second etalon are mounted on the temperature control device. The first etalon includes a liquid crystal,
3. The laser module according to claim 1 , wherein the liquid crystal has a refractive index that changes when an electric signal is applied thereto. An external resonant laser having a first etalon having a periodic wavelength peak in transmission characteristics, and the wavelength peak being changed by a given electrical signal, and having a periodic wavelength peak in transmission characteristics, and the external A second etalon that transmits light output from the resonant laser; a temperature control device that controls the temperature of the first etalon and the temperature of the second etalon; and a temperature control device that is spaced apart from the temperature control device. A first temperature detection unit that detects a temperature of the first etalon or a temperature substantially equal to a temperature of the first etalon, and a second temperature detection unit that detects the temperature of the second etalon. The relative relationship between the temperature change of the first etalon and the fluctuation amount of the periodic wavelength peak of the first etalon is known , and the first etalon, the second etalon, and the first etalon 2 Degree detecting unit is a control method for a laser module that is mounted on the temperature control device on,
The temperature control device so that the temperature detected by the first temperature detection unit is equal to the temperature of the first etalon when the external resonant laser outputs light of a desired wavelength at a predetermined outside air temperature. A first step in which
A second step in which an electrical signal applied to the first etalon is applied to the first etalon in a state where the external resonant laser at a predetermined outside temperature outputs light of a desired wavelength;
A third step in which an electrical signal applied to the first etalon is controlled so that a peak wavelength of output light of the external resonant laser becomes a desired wavelength;
The temperature controller detects the temperature of the second etalon when the external resonant laser outputs light of a desired wavelength at a predetermined outside air temperature. A fourth step to be controlled;
The relative change between the temperature change amount of the first etalon and the electric signal value applied to the first etalon so as to cancel the change in the periodic wavelength peak of the first etalon that occurs in the fourth step. And a fifth step of controlling an electric signal applied to the first etalon based on the relationship. The first etalon includes a liquid crystal,
5. The method of controlling a laser module according to claim 4 , wherein the liquid crystal has a refractive index that changes when an electric signal is applied thereto. 5. The laser module control method according to claim 4, wherein the first and second steps are performed at an outside air temperature different from the predetermined outside air temperature. 5. The laser module control method according to claim 4 , wherein the third to fifth steps are performed at an outside air temperature different from the predetermined outside air temperature.

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