JP2004347716A - Waveguide type optical device and method for monitoring output light - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simply monitor various types of information such as the intensity of a plurality of light waves utilized in optical communication in a multichannel multiband optical communication technique utilizing WDM (Wavelength Division Multiplexing). <P>SOLUTION: A waveguide type optical device is provided with: a waveguide substrate with a plurality of optical waveguides formed thereon; and an optical fiber array disposed adjacent to the waveguide substrate and having a plurality of optical fibers to derive optical waves guided through the optical waveguides to the outside. At least one optical waveguide out of the plurality of optical waveguides is not connected to the optical fiber and kept open, and is made to emit light on the basis of an on/off signal. An end face of the optical fiber array on the side opposite to the waveguide substrate is inclined upward or downward. The emitted light is reflected upward or downward at the end face of the optical fiber array and is taken out to the outside for the purpose of monitoring the intensity of the emitted light. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a waveguide-type optical element and a method for monitoring output light that can be suitably used in a multi-band optical communication technology using a wavelength division multiplexing (WDM) method.
[0002]
[Prior art]
In a multi-channel multi-band optical communication technology using WDM, predetermined optical information is superimposed on each of a plurality of lightwaves, and the plurality of lightwaves are transmitted through corresponding optical fibers. The transmission of information is realized. In such a multi-channel multi-band optical communication technology, the plurality of light waves are guided through a multi-channel optical modulation element in order to appropriately extract a plurality of pieces of optical information superimposed on the plurality of light waves as signal light. Waves are turned on and off as appropriate.
[0003]
On the other hand, in the above-described multi-channel multi-band optical communication technology, it is necessary to keep the intensity of the plurality of light waves substantially constant. Therefore, it is required to monitor the intensities of the plurality of light waves.
[0004]
Conventionally, the intensity of light waves is monitored by introducing a plurality of light waves into the multi-channel light modulation element and then performing a predetermined on / off control as disclosed in, for example, JP-A-2000-180803. After extracting only the light wave as the signal light, the measurement is performed by monitoring the intensity of the signal light.
[0005]
[Problems to be solved by the invention]
However, the signal light has target optical information superimposed thereon, and if an attempt is made to monitor the intensity of the signal light, a complicated electric circuit for monitoring the intensity is required. Further, in actual optical communication, noise from the electric circuit is superimposed on the signal light, and good optical communication may not be performed.
[0006]
An object of the present invention is to easily monitor various information such as the intensity of a plurality of light waves used for optical communication in a multi-channel multi-band optical communication technology using WDM.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides:
An optical fiber array having a waveguide substrate on which a plurality of optical waveguides are formed, and a plurality of optical fibers provided to be adjacent to the waveguide substrate and for guiding a light wave guided in the optical waveguide to the outside With
At least one of the plurality of optical waveguides is opened without being connected to the optical fiber, and emits radiated light based on an ON signal or an OFF signal,
The end face of the optical fiber array facing the waveguide substrate is inclined downward or upward, and the emitted light is reflected upward or downward at the end face of the optical fiber array, and is taken out. The present invention relates to a waveguide-type optical element (first waveguide-type optical element) characterized in that:
[0008]
Also, the present invention
An optical fiber array having a waveguide substrate on which a plurality of optical waveguides are formed, and a plurality of optical fibers provided to be adjacent to the waveguide substrate and for guiding a light wave guided in the optical waveguide to the outside With
At least one of the plurality of optical waveguides is opened without being connected to the optical fiber, and emits radiated light based on an ON signal or an OFF signal,
A slit is provided inside the optical fiber array, and the emitted light is reflected downward or upward by the slit, and is taken out to the outside. Optical element).
[0009]
Further, the present invention provides
An optical fiber array having a waveguide substrate on which a plurality of optical waveguides are formed, and a plurality of optical fibers provided to be adjacent to the waveguide substrate and for guiding a light wave guided in the optical waveguide to the outside With
At least one of the plurality of optical waveguides is opened without being connected to the optical fiber, and emits radiated light based on an ON signal or an OFF signal,
The optical fiber array includes a first optical fiber fixing member having a refractive index n1 and a second optical fiber fixing member having a refractive index n2, and the radiated light includes the first optical fiber fixing member, Propagation between the second optical fiber fixing member and the refractive index difference between the refractive index n1 of the first optical fiber fixing member and the refractive index n2 of the second optical fiber fixing member is performed. The present invention relates to a waveguide-type optical element (third waveguide-type optical element) characterized in that it is bent downward or upward to be taken out.
[0010]
The present inventors have conducted intensive studies to achieve the above object. As a result, in multi-channel multi-band optical communication technology, instead of using signal light from a waveguide-type optical element such as an optical modulation element to monitor various information such as intensity of a light wave used for communication, The present inventors have conceived of using radiated light generated when the waveguide type optical element is turned on or off and the signal light is not output for monitoring various information.
[0011]
Then, according to the first waveguide type optical element of the present invention, the end face of the optical fiber array constituting the optical element facing the waveguide substrate is inclined downward or upward, whereby the radiation is achieved. Light becomes reflected upward or downward at the end face of the optical fiber array. Therefore, the emitted light can be easily taken out of the first waveguide type optical element, and various information such as intensity can be easily monitored.
[0012]
Further, according to the second waveguide type optical element of the present invention, by providing a slit inside the optical fiber array constituting this optical element, the emitted light is reflected downward or upward by the slit. . Therefore, the emitted light can be easily taken out of the second waveguide type optical element, and various information such as intensity can be easily monitored.
[0013]
Further, according to the third waveguide type optical element of the present invention, the optical fiber array constituting this optical element is fixed to a first optical fiber fixing member having a refractive index n1 and a second optical fiber fixing member having a refractive index n2. And a member for transmitting the radiated light between the first optical fiber fixing member and the second optical fiber fixing member. At this time, the radiated light is bent downward or upward due to a refractive index difference between the refractive index n1 of the first optical fiber fixing member and the refractive index n2 of the second optical fiber fixing member. Therefore, it can be easily taken out of the third waveguide type optical element. As a result, various information such as intensity can be easily monitored.
[0014]
Thus, according to the present invention, instead of directly monitoring a light wave used as a signal light, instead of using a radiation light obtained when the light wave is turned on / off using a waveguide type optical element, It monitors various information of light waves. Therefore, it is not necessary to provide a complicated electric circuit or the like, and good optical transmission, that is, good optical communication can be realized without noise or the like caused by the electric circuit being superimposed on the signal light.
[0015]
Hereinafter, an output monitoring method using the above-described waveguide optical element, and details and other features of the present invention will be described in embodiments of the present invention described below.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a plan view showing a light modulation element as an example of the waveguide type optical element of the present invention, and FIG. 2 is a side view showing an output side optical fiber array of the light modulation element shown in FIG. FIG. 3 is a cross-sectional view of the output-side optical fiber array shown in FIG. 2 taken along line AA.
[0017]
The optical modulation element 10 shown in FIG. 1 has a waveguide substrate 11, an incident side optical fiber array 12, and an exit side optical fiber array 22. Eight sets of Mach-Zehnder type optical waveguides 13-1 to 13-8 are provided on the waveguide substrate 11, and modulation electrodes 14-1 to 14-8 are provided for each optical waveguide. Further, the branch optical waveguides constituting the optical waveguides 13-1 to 13-8 are combined on the emission side of the optical modulation element 10 to form X couplers 17-1 to 17-8, and subsequently, the signal light The optical waveguides 15-1 to 15-8 for extraction are provided, and the optical waveguides 16-1 to 16-8 for extraction of radiation light having the other end open.
[0018]
The incident side optical fiber array 12 has eight optical fibers 12-1 to 12-8, which are connected to the optical waveguides 13-1 to 13-8, respectively. The emission-side optical fiber array 22 has eight optical fibers 22-1 to 22-8, which are connected to optical waveguides 15-1 to 15-8 for extracting signal light, respectively. Thereby, the light modulation element 10 functions as an eight-channel light modulation element.
[0019]
As shown in FIG. 2, the output-side optical fiber array 22 has a fixing member 23, and its output-side end face 23A is inclined downward. As shown in FIG. 3, the fixing member 23 of the emission-side optical fiber array 22 has an uneven shape, and the optical fibers 22-1 to 22-8 are embedded and fixed in recesses of the fixing member 23. . Although not shown, also in the incident side optical fiber array 12, the fixing member may be formed in an uneven shape, and the optical fibers 12-1 to 12-8 may be embedded and fixed in the concave portion of the fixing member. it can.
[0020]
In the optical modulation device 10 shown in FIG. 1, for example, when a light wave in which predetermined optical information is superimposed on the optical fiber 12-1 in the incident optical fiber array 12, is introduced from the optical fiber 12-1 to the optical waveguide. On / off control is performed by receiving the modulation signal from the modulation electrode 14-1 introduced into the modulation electrode 13-1.
[0021]
Specifically, when extracting the lightwave as signal light, the lightwave is introduced into the light guide 13-1 without giving any modulation signal from the modulation electrode 14-1 to the lightwave. It is extracted to the outside through the signal light extraction optical waveguide 15-1. On the other hand, when the light wave is cut off without being taken out as a signal light, the light wave is introduced into the optical waveguide 13-1, and a predetermined modulation signal is applied to one of the branched light waves from the modulation electrode 14-1. Applied to cause phase modulation. Then, in the X-coupler 17-1, the one lightwave that has undergone phase modulation and the other lightwave that has not undergone phase modulation are superimposed and cancel each other.
[0022]
In this example, based on the driving state of the light modulation element 10, the above-described modulation signal is applied, the signal light is extinguished, the ON state is set, and the signal light is extracted without applying the modulation signal, the OFF state is set. And However, based on the extraction state of the signal light, the case where the signal light is extinguished may be set to the off state, and the case where the signal light is extracted without applying the modulation signal may be set to the on state.
[0023]
When the light modulator 10 is in the ON state and the light wave incident on the optical fiber 13-1 is extinguished, the radiated light E is generated in the X coupler 17-1. The radiated light E reaches the boundary surface with the optical fiber array 22 by being guided in the radiated light extraction optical waveguide 16-1 having the other end opened. After that, the radiated light E is guided in the convex portion of the fixing member 23 of the optical fiber array 22 and reaches the emission side end face 23A. Since the emission-side end face 23A is inclined downward, the radiated light E is reflected downward by the emission-side end face 23A and is extracted outside.
[0024]
Therefore, if a predetermined measuring instrument or the like is arranged below the optical fiber array 22, predetermined information can be obtained from the emitted light E. For example, if a photodetector is used as the measuring device, the intensity of the radiated light E can be measured.
[0025]
Since the synchrotron light E has inherited all the information of the disappeared light wave, for example, by measuring the intensity of the synchrotron light E, the intensity of the light wave is indirectly measured, and the intensity is known. Will be able to do it. As a result, by monitoring various information such as the intensity of the emitted light E, it becomes possible to monitor various information such as the intensity of the light wave.
[0026]
In the above description, only the light wave introduced into the optical fiber 12-1 has been described, but the same operation is performed on the light waves introduced into the other optical fibers 12-2 to 12-8. The emitted light can be obtained, and various information such as the intensity of the light wave can be monitored by monitoring the information such as the intensity of the emitted light.
[0027]
Further, although the emission-side end face 23A of the fixing member 23 of the emission-side optical fiber array 22 is inclined downward, it may be inclined upward. In this case, the emitted light is reflected upward. Therefore, in this case, a predetermined measuring instrument or the like is arranged above the optical fiber array 22 to monitor various information such as the intensity of the emitted light.
[0028]
As described above, according to the light modulation device 10 shown in FIG. 1, instead of directly monitoring the light wave used as the signal light, the radiation light obtained when the light wave is turned on / off using the light modulation device 10 is controlled. Is used to monitor various information of the light wave. Therefore, it is not necessary to provide a complicated electric circuit or the like for monitoring various information such as the intensity of the light wave, and noise and the like caused by the electric circuit are not superimposed on the signal light, thereby achieving good optical transmission. That is, good optical communication can be realized.
[0029]
FIG. 4 is a configuration diagram showing another example of the waveguide type optical element of the present invention. The waveguide type optical element of this example has the same configuration as the waveguide type optical element shown in FIG. 1 except for the configuration of the emission side optical fiber array. Therefore, FIG. 4 shows only the configuration of the output side optical fiber array.
[0030]
In the output side optical fiber array 32 shown in FIG. 4, a slit 35 is provided at substantially the same level as the optical fiber 22-1 inside the fixing member 33. The fixing member 33 also has an uneven shape as shown in FIG. 3, and the optical fibers 22-1 to 22-8 are embedded and fixed in the recesses of the fixing member 33.
[0031]
In this example, for example, the radiated light E emitted from the X coupler 17-1 of the optical waveguide 13-1 is guided in the radiated light extraction optical fiber 16-1, and furthermore, the emission side optical fiber array 32 The light guides the inside of the convex portion of the fixing member 33 to reach the slit 35. Since the slit 35 is inclined downward, the radiated light E is reflected downward and is extracted to the outside.
[0032]
Therefore, if a predetermined measuring device or the like is arranged below the optical fiber array 32, predetermined information, that is, information on the light wave, can be obtained from the emitted light E. For example, if a photodetector is used as the measuring device, the intensity of the emitted light E, that is, the intensity of the light wave can be measured.
[0033]
Also in this example, it is possible to obtain radiated light by performing the same operation on the light waves introduced into the other optical fibers 12-2 to 12-8. By monitoring, various information such as the intensity of the light wave can be monitored. Further, the slit 35 provided inside the fixing member 33 of the emission-side optical fiber array 32 can be inclined upward above the optical fiber 22-1.
[0034]
FIG. 5 is a configuration diagram showing another example of the waveguide type optical element of the present invention. The waveguide type optical element of this example has the same configuration as the waveguide type optical element shown in FIG. 1 except for the configuration of the emission side optical fiber array. Therefore, FIG. 5 shows only the configuration of the emission-side optical fiber array.
[0035]
In the output side optical fiber array 42 shown in FIG. 5, the fixing member 43 is connected to the lower refractive index portion 43-1 (refractive index n1) provided above the optical fiber 22-1 and the lower side of the optical fiber 22-1. Is provided with a high refractive index portion 43-2 (refractive index n2). The fixing member 43 also has an uneven shape as shown in FIG. 3, and the optical fibers 22-1 to 22-8 are embedded and fixed in the recesses of the fixing member 43.
[0036]
In this example, for example, the radiated light E emitted from the X coupler 17-1 of the optical waveguide 13-1 is guided in the radiated light extraction optical fiber 16-1, and further, the outgoing side optical fiber array 42 Is guided between the low refractive index portion 43-1 and the high refractive index portion 43-2 of the fixing member 43 of FIG. At this time, since the relationship of n1 <n2 holds, the emitted light E is bent downward toward the high refractive index side, that is, toward the high refractive index portion 43-2. Next, the radiated light E propagates through the high refractive index portion 43-2, reaches the emission side end surface 43A inclined downward, is reflected downward, and is extracted outside.
[0037]
Therefore, if a predetermined measuring device or the like is arranged below the optical fiber array 42, predetermined information, that is, information on the light wave, can be obtained from the emitted light E. For example, if a photodetector is used as the measuring device, the intensity of the emitted light E, that is, the intensity of the light wave can be measured.
[0038]
Also in this example, it is possible to obtain radiated light by performing the same operation on the light waves introduced into the other optical fibers 12-2 to 12-8. By monitoring, various information such as the intensity of the light wave can be monitored. Further, the optical fiber 12-1 may be composed of a high refractive index portion on the upper side, and the optical fiber 12-1 may be composed of a low refractive index portion on the lower side. In this case, the emitted light E bends upward toward the high refractive index portion. Further, the exit side end face 43A can be inclined upward.
[0039]
In the example shown in FIG. 5, the emission-side end face of the fixing member 43 is inclined, but the radiation light E bent toward the high-refractive-index portion 43-2 is directly provided without such an inclination. The light may be guided and taken out from the lower surface of the fixing member 43.
[0040]
As described above, the present invention has been described in detail based on the embodiments of the present invention with specific examples. However, the present invention is not limited to the above description, and any modifications or changes may be made without departing from the scope of the present invention. Changes are possible. For example, in the above specific example, the case of a light modulation element has been described as a specific example of the waveguide type optical element, but the present invention can also be used for other optical elements such as an attenuator.
[0041]
【The invention's effect】
As described in detail above, according to the present invention, in a multi-channel multi-band optical communication technology using WDM, various information such as the intensity of a plurality of light waves used for optical communication can be easily monitored. Become like
[Brief description of the drawings]
FIG. 1 is a plan view showing a light modulation device as an example of a waveguide optical device of the present invention.
FIG. 2 is a side view showing an optical fiber array on an output side of the light modulation device shown in FIG.
3 is a cross-sectional view of the output-side optical fiber array shown in FIG. 2 taken along line AA.
FIG. 4 is a configuration diagram showing another example of the waveguide type optical element of the present invention.
FIG. 5 is a configuration diagram showing another example of the waveguide type optical element of the present invention.
[Explanation of symbols]
Reference Signs List 10 optical modulation element 11 waveguide substrate 12 incident side optical fiber array 12-1 to 12-8 optical fiber 13-1 to 13-8 optical waveguide 14-1 to 14-8 modulation electrode 15-1 to 15-8 signal Optical fibers 16-1 to 16-8 for extracting light Optical fibers 17-1 to 17-8 for extracting emitted light X couplers 22, 32, 42 Output-side optical fiber arrays 22-1 to 22-8 Optical fibers 23, 33, 43 Fixing member 35 Slit 43-1 Low refractive index portion (of fixing member) 43-2 High refractive index portion (of fixing member)

Claims (11)

An optical fiber array having a waveguide substrate on which a plurality of optical waveguides are formed, and a plurality of optical fibers provided adjacent to the waveguide substrate and for guiding light waves guided through the optical waveguide to the outside With
At least one of the plurality of optical waveguides is opened without being connected to the optical fiber, and emits radiated light based on an ON signal or an OFF signal,
The end face of the optical fiber array facing the waveguide substrate is inclined downward or upward, and the emitted light is reflected upward or downward at the end face of the optical fiber array, and is taken out. A waveguide-type optical element, characterized in that: An optical fiber array having a waveguide substrate on which a plurality of optical waveguides are formed, and a plurality of optical fibers provided adjacent to the waveguide substrate and for guiding light waves guided through the optical waveguide to the outside With
At least one of the plurality of optical waveguides is opened without being connected to the optical fiber, and emits radiated light based on an ON signal or an OFF signal,
A waveguide type optical element, wherein a slit is provided inside the optical fiber array, and the emitted light is reflected downward or upward by the slit, and is taken out to the outside. An optical fiber array having a waveguide substrate on which a plurality of optical waveguides are formed, and a plurality of optical fibers provided adjacent to the waveguide substrate and for guiding light waves guided through the optical waveguide to the outside With
At least one of the plurality of optical waveguides is opened without being connected to the optical fiber, and emits radiated light based on an ON signal or an OFF signal,
The optical fiber array includes a first optical fiber fixing member having a refractive index n1 and a second optical fiber fixing member having a refractive index n2, and the radiated light includes the first optical fiber fixing member, Propagation between the second optical fiber fixing member and the refractive index difference between the refractive index n1 of the first optical fiber fixing member and the refractive index n2 of the second optical fiber fixing member is performed. A waveguide-type optical element characterized by being bent downward or upward to be taken out. An end face of the optical fiber array facing the waveguide substrate is inclined downward or upward, and the radiation light bent downward or upward is reflected upward or downward at the end face of the optical fiber array. 4. The waveguide type optical element according to claim 3, wherein the waveguide type optical element is taken out. The waveguide type optical element according to claim 1, wherein a modulation electrode is provided on the waveguide substrate, and functions as a light modulation element. The waveguide type optical element according to claim 1, wherein the emitted light is used to monitor an intensity of an optical signal guided through the plurality of optical waveguides. An optical fiber array having a waveguide substrate on which a plurality of optical waveguides are formed, and a plurality of optical fibers provided adjacent to the waveguide substrate and for guiding light waves guided through the optical waveguide to the outside A method for monitoring output light in a waveguide optical element comprising:
At least one of the plurality of optical waveguides is opened without being connected to the optical fiber, and a step of emitting radiation based on an ON signal or an OFF signal,
The end face of the optical fiber array facing the waveguide substrate is inclined downward or upward, and the radiated light is reflected upward or downward at the end face of the optical fiber array, and the output light is reflected. Taking out to monitor the intensity;
A method for monitoring output light, comprising: An optical fiber array having a waveguide substrate on which a plurality of optical waveguides are formed, and a plurality of optical fibers provided adjacent to the waveguide substrate and for guiding light waves guided through the optical waveguide to the outside A method for monitoring output light in a waveguide optical element comprising:
At least one of the plurality of optical waveguides is opened without being connected to the optical fiber, and a step of emitting radiation based on an ON signal or an OFF signal,
Providing a slit inside the optical fiber array, reflecting the emitted light downward or upward by the slit, and taking it out to monitor the intensity of the output light,
A method for monitoring output light, comprising: An optical fiber array having a waveguide substrate on which a plurality of optical waveguides are formed, and a plurality of optical fibers provided adjacent to the waveguide substrate and for guiding light waves guided through the optical waveguide to the outside A method for monitoring output light in a waveguide optical element comprising:
At least one of the plurality of optical waveguides is opened without being connected to the optical fiber, and a step of emitting radiation based on an ON signal or an OFF signal,
The optical fiber array is composed of a first optical fiber fixing member having a refractive index n1 and a second optical fiber fixing member having a refractive index n2, and the emitted light is emitted from the first optical fiber fixing member. Propagating between the second optical fiber fixing member and the refractive index difference between the refractive index n1 of the first optical fiber fixing member and the refractive index n2 of the second optical fiber fixing member. Wherein the output light is bent downward or upward to be taken out to monitor the intensity of the output light. An end surface of the optical fiber array facing the waveguide substrate is inclined downward or upward, and the radiation light bent downward or upward is reflected upward or downward at the end surface of the optical fiber array. The method for monitoring output light according to claim 9, wherein the output light is taken out to monitor the intensity of the output light. The method for monitoring output light according to any one of claims 7 to 10, wherein a modulation electrode is provided on the waveguide substrate, and the waveguide-type optical element functions as a light modulation element. .

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