JP2018063354A - Method of manufacturing semiconductor optical amplifier module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a semiconductor optical amplifier module with which it is possible to suppress a change in the optical intensity of signal light after amplification that arises from the polarization dependency of a semiconductor optical amplifier in a semiconductor optical amplifier module in which an isolator is arranged between an input-side optical fiber and the semiconductor optical amplifier.SOLUTION: The method includes: a step S3 for connecting an input-side optical fiber 11 to a signal light source 30 that generates non-polarized light as signal light, and connecting an output-side optical fiber 12 to an optical power meter 31 that measures the optical intensity of signal light after amplification that is outputted from an SOA chip 10 or spontaneous emission light; and steps S6, S7 for causing the signal light from the signal light source 30 to be transmitted by the input-side optical fiber 11, and fixing, while the signal light is inputted to the SOA chip 10, one end of the input-side optical fiber 11 at a position where the optical intensity of the signal light after amplification that is measured by the optical power meter 31 becomes maximum.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a method for manufacturing a semiconductor optical amplifier module, and more particularly to a method for manufacturing a semiconductor optical amplifier module having an isolator.

  Conventionally, optical fiber amplifiers and semiconductor optical amplifiers (SOA) are mainly known as optical amplifiers that directly amplify light without converting it into an electrical signal. In particular, the SOA has an advantage of being small and capable of amplifying light over a wide wavelength band (for example, see Non-Patent Document 1).

  An optical module including such an SOA (hereinafter referred to as “SOA module”), for example, amplifies signal light input via an input side optical fiber in a state where a drive current is supplied, and outputs an output side optical fiber. The SOA chip and the lens that are output from are fixed on the same substrate on the electronic cooling element (Peltier element). Further, an isolator is disposed between the SOA chip and the input side and output side optical fibers.

  For the SOA module as described above, it is necessary to align an optical fiber at the time of manufacture and to perform an environmental test such as a temperature cycle test when the manufacture is completed. In any case, whether or not the optical coupling rate between the input side and output side optical fibers and the SOA chip is in a good state is determined by measuring the light intensity of the light output from the SOA module. be able to.

  For the output side optical fiber, a power meter for measuring the light intensity is connected to the end opposite to the side facing the SOA chip, and alignment is performed while measuring the light intensity of the spontaneous emission light emitted by the SOA chip itself. Is possible.

  However, the spontaneous emission light emitted by the SOA chip itself is blocked by the isolator and does not enter the input side optical fiber. Therefore, for the input side optical fiber, signal light is input from the end opposite to the side facing the SOA chip, and the light intensity of the signal light amplified through the SOA chip and output from the output side optical fiber is measured. While aligning.

Atsushi Yamada, Toshinobu Otsubo, Akihiko Asai, Katsunori Shinone, Shinichi Onuki, Masaru Hamada, “Semiconductor Optical Amplifier”, Anritsu Technical, Anritsu Corporation, March 1994, No. 67, p. 22-27

  However, in general, the polarization state of light transmitted through the optical fiber changes with changes in the environment (external force, temperature, pressure). For example, the polarization state changes even if the operator moves the optical fiber unexpectedly during alignment. When the polarization state changes on the input side optical fiber side, even if the SOA chip has a slight polarization dependency, the light intensity of the amplified signal light also changes.

  The solid line in the graph of FIG. 5 indicates the optical coupling loss between the SOA chip and the input side optical fiber when there is no change in the polarization state of the signal light in the input side optical fiber. Here, the case where the amount of axial deviation between the optical axis of the SOA chip and the optical axis of the input side optical fiber is 0 (zero) is 0 dB. The arrow in the figure indicates that the optical intensity of the signal light output from the output side optical fiber changes due to the change in the polarization state of the signal light in the input side optical fiber, resulting in an apparent optical coupling loss. For example, it represents a change of about 1 dB. Therefore, when there is a change in the polarization state, it is impossible to accurately estimate the actual axis deviation amount from the value of the (apparent) optical coupling loss.

  Thus, in the conventional SOA module as disclosed in Non-Patent Document 1, the optical coupling rate between the original optical fiber and the SOA chip is reflected by the change in the polarization state of the signal light in the optical fiber. There is a problem that the measured light intensity cannot be measured accurately.

  The present invention has been made to solve such a conventional problem, and in a semiconductor optical amplifier module in which an isolator is disposed between an input side optical fiber and a semiconductor optical amplifier, the periphery of the input side optical fiber is provided. To provide a method of manufacturing a semiconductor optical amplifier module capable of suppressing a change in optical intensity of amplified signal light due to polarization dependence of a semiconductor optical amplifier even when the environment of the semiconductor optical amplifier changes With the goal.

  In order to solve the above problems, a method of manufacturing a semiconductor optical amplifier module according to claim 1 of the present invention includes a semiconductor optical amplifier that amplifies input signal light, and an input side that inputs the signal light to the semiconductor optical amplifier. An optical fiber, an output-side optical fiber that transmits the amplified signal light or spontaneous emission light output from the semiconductor optical amplifier to the outside, and the signal light output from one end side of the input-side optical fiber. An input side lens for condensing toward the light incident end face of the semiconductor optical amplifier, and the amplified signal light or spontaneous emission light output from the light emitting end face of the semiconductor optical amplifier on one end side of the output side optical fiber An output side lens that condenses the light toward the input side, and an eye that is disposed between one end side of the input side optical fiber and the input side lens and blocks light from the semiconductor optical amplifier to the input side optical fiber. A semiconductor optical amplifier module comprising: a driving current supply step of starting supply of a driving current to the semiconductor optical amplifier to generate spontaneous emission light from the semiconductor optical amplifier; and the input One end side of the side optical fiber is provisionally disposed at a position where it is optically coupled to the light incident end face of the semiconductor optical amplifier via the isolator and the input side lens, and one end side of the output side optical fiber is placed on the output side. An optical fiber provisional arrangement step of temporarily arranging at a position where it is optically coupled to the light emitting end face of the semiconductor optical amplifier via a side lens; and a signal light source for generating non-polarized light as the signal light. And measuring the light intensity of the amplified signal light or spontaneous emission light output from the light emitting end face of the semiconductor optical amplifier. Connecting the other end of the output-side optical fiber to an apparatus; and transmitting the signal light from the signal light source from the other end to the one-end side of the input-side optical fiber, and the signal light is transmitted to the semiconductor An input side optical fiber position that fixes one end side of the input side optical fiber at a position where the light intensity of the amplified signal light measured by the light intensity measuring device is maximized while being input to the optical amplifier And a fixing step.

  As described above, the method of manufacturing a semiconductor optical amplifier module according to the present invention includes a semiconductor optical amplifier module in which an isolator is disposed between the input side optical fiber and the semiconductor optical amplifier. Wave signal light is input to perform alignment. With this configuration, even when the environment around the input-side optical fiber changes, the input-side optical fiber suppresses the change in the light intensity of the amplified signal light due to the polarization dependence of the semiconductor optical amplifier. Therefore, stable alignment can be performed.

  In the method for manufacturing a semiconductor optical amplifier module according to claim 2 of the present invention, the position at which the light intensity of the spontaneous emission light measured by the light intensity measuring device is maximized before the input side optical fiber position fixing step. And an output side optical fiber position fixing step of fixing one end side of the output side optical fiber.

  With this configuration, the manufacturing method of the semiconductor optical amplifier module according to the present invention can perform alignment using the spontaneous emission light emitted from the semiconductor optical amplifier for the output side optical fiber.

  The method of manufacturing a semiconductor optical amplifier module according to claim 3 of the present invention further includes a lens position fixing step of fixing the positions of the input side lens and the output side lens before the optical fiber temporary placement step. It is.

  With this configuration, the method for manufacturing a semiconductor optical amplifier module according to the present invention allows the input side lens and the output side lens, which have been adjusted in the lens position adjustment process described later, to be placed between the signal light source and the light intensity measuring device on the input side. The optical fiber and the output side optical fiber can be fixed without being arranged.

  According to a fourth aspect of the present invention, there is provided a method for manufacturing a semiconductor optical amplifier module, wherein the input side lens and the output side are generated using spontaneous emission light generated from the semiconductor optical amplifier before the lens position fixing step. A lens position adjusting step for adjusting the position of the lens, wherein the lens position adjusting step measures the light intensity of spontaneously emitted light generated from the semiconductor optical amplifier that has passed through the slit with the light intensity measuring device; A configuration in which the positions of the input side lens and the output side lens are adjusted by checking the positional fluctuation of the input side lens and the output side lens based on the fluctuation of the light intensity measured by the light intensity measuring device. is there.

  With this configuration, the manufacturing method of the semiconductor optical amplifier module according to the present invention allows the input side lens and the output side to be output in a state where the input side optical fiber and the output side optical fiber are not disposed between the signal light source and the light intensity measuring device. The position of the side lens can be optimized.

  The present invention provides a semiconductor optical amplifier module in which an isolator is disposed between an input-side optical fiber and a semiconductor optical amplifier. Even when the environment around the input-side optical fiber changes, the polarization dependence of the semiconductor optical amplifier The present invention provides a method for manufacturing a semiconductor optical amplifier module capable of suppressing a change in light intensity of amplified signal light due to the characteristics.

It is a side view which shows the structure of the SOA module in embodiment of this invention. It is a top view which shows the structure of the SOA module in embodiment of this invention. It is the schematic which shows the structure for aligning of the SOA module in embodiment of this invention. 3 is a flowchart illustrating a method for manufacturing an SOA module according to an embodiment of the present invention. It is a graph which shows the relationship between the optical coupling loss of the conventional SOA module, and the amount of axial deviation from an optical axis.

  Embodiments of a method for manufacturing a semiconductor optical amplifier module according to the present invention will be described below with reference to the drawings. In addition, the dimensional ratio of each structure on each drawing does not necessarily correspond with the actual dimensional ratio.

  First, the configuration of the semiconductor optical amplifier module in the embodiment of the present invention will be described.

  As shown in FIGS. 1 and 2, a butterfly-type SOA module 1 includes an SOA chip 10 as a semiconductor optical amplifier that amplifies input signal light, and an input-side optical fiber 11 that inputs signal light to the SOA chip 10. And an output side optical fiber 12 that transmits the amplified signal light or spontaneous emission light output from the SOA chip 10 to the outside. Here, as the input side optical fiber 11 and the output side optical fiber 12, a single mode optical fiber can be used.

  As the SOA chip 10, it is preferable to use a chip capable of optical amplification with a gain difference between polarizations of 1 dB or less over a wide gain band in a wavelength band for optical communication.

  Further, the SOA module 1 includes an input side lens 13 that condenses the signal light output from one end side of the input side optical fiber 11 toward the light incident end face 10a of the SOA chip 10, and a light emitting end face 10b of the SOA chip 10. The output side lens 14 which condenses the amplified signal light or spontaneous emission light output from the optical fiber 12 toward one end side of the output side optical fiber 12 and a substrate 15 are mainly provided.

  The SOA chip 10, the input side lens 13, the output side lens 14, and the substrate 15 are stored in a rectangular parallelepiped package (housing) 16 having a hollow inside. The input side optical fiber 11 is connected to a wall surface 16 a on the back side of the package 16. Further, the output side optical fiber 12 is connected to a wall surface 16 b on the front side of the package 16, and guides the light condensed by the output side lens 14 to the outside of the package 16.

  1 and 2 show a configuration in which each of the input side lens 13 and the output side lens 14 is composed of a single lens, these lenses may have a configuration of a two-lens system.

  As shown in FIG. 2, a plurality of terminals 17 to / from which signals for controlling the operation of the SOA module 1 are input / output are attached to both side walls 16c and 16d of the package 16 at predetermined intervals. These terminals 17 are soldered to a pattern on an arbitrary printed board. For example, out of the plurality of terminals 17, for example, two terminals 17 a and 17 b are electrode terminals for supplying a drive current to the SOA chip 10.

  Further, a flange portion 18 is provided at a lower front end portion and a lower rear end portion of the package 16, and an attachment hole 19 for screwing the SOA module 1 to an arbitrary heat radiating plate is provided in the flange portion 18.

  As shown in FIG. 1, a Peltier element 20 is fixed to the upper surface of the bottom wall 16 e in the package 16. The substrate 15 is fixed on the Peltier element 20.

  The SOA chip 10 is fixed on the substrate 15 via the submount 21. Further, a lens holder 22 a for holding the input side lens 13 and a lens holder 22 b for holding the output side lens 14 are fixed on the substrate 15. The lens holders 22a and 22b are made of a metal such as stainless steel.

  A cylindrical opening 23 a for guiding signal light from the input side optical fiber 11 to the SOA chip 10 is formed on the wall surface 16 a of the package 16. Similarly, a cylindrical opening 23b for guiding the amplified signal light emitted from the SOA chip 10 to the outside is formed on the wall surface 16b of the package 16.

  In the cylindrical opening 23a, an isolator 24 disposed between one end side of the input side optical fiber 11 and the input side lens 13 and blocking light from the SOA chip 10 to the input side optical fiber 11, and a window Glass 25a is stored. On the other hand, a window glass 25b is stored in the cylindrical opening 23b.

  An output isolator for blocking light from the output side optical fiber 12 to the SOA chip 10 may be further disposed between one end side of the output side optical fiber 12 and the output side lens 14.

  A cylindrical ferrule 26 a is attached to the distal end portion of the input side optical fiber 11. The cylindrical ferrule 26a is fixed to the wall surface 16a of the package 16 by a sleeve 27a. Further, a cylindrical cover 28 a surrounding the entire ferrule 26 a and a part of the input side optical fiber 11 is fixed to the wall surface 16 a of the package 16.

  Similarly, a cylindrical ferrule 26b attached to the distal end portion of the output side optical fiber 12 is fixed to the wall surface 16b of the package 16 by a sleeve 27b. Further, a cylindrical cover 28 b surrounding the entire ferrule 26 b and a part of the output side optical fiber 12 is fixed to the wall surface 16 b of the package 16.

  Here, the covers 28a and 28b are connected and fixed to the wall surfaces 16a and 16b of the package 16 by welding, respectively. The ferrules 26a and 26b are fixed in the sleeves 27a and 27b by welding, respectively. Since the package 16, the sleeves 27a and 27b, and the covers 28a and 28b are connected by welding, each is made of a metal material such as stainless steel (SUS).

  Hereinafter, a method for manufacturing the SOA module 1 configured as described above will be described with reference to FIGS.

  First, the SOA chip 10 is fixed in the package 16, and the input side lens 13 and the output side lens 14 are temporarily arranged (step S1).

  Next, supply of drive current to the SOA chip 10 is started (step S2: drive current supply step). As a result, spontaneous emission light is generated from the SOA chip 10.

  Next, the positions of the input side lens 13 and the output side lens 14 are adjusted. The position adjustment of the input side lens 13 and the output side lens 14 is performed by confirming the fluctuation of the light intensity of the spontaneous emission light from the SOA chip 10 measured by the light receiving sensor of the optical power meter 31 and measuring with the optical power meter 31. The positions of the input side lens 13 and the output side lens 14 are adjusted in the package 16 so that the obtained light intensity becomes an optimum value (step S3: lens position adjustment step).

  When the diameter of the light receiving sensor of the optical power meter 31 is larger than the fluctuation amount of the position of the input side lens 13 and the output side lens 14, a member having a slit is installed in the immediate vicinity of the light receiving sensor of the optical power meter 31. The light intensity of spontaneously emitted light generated from the SOA chip 10 that has passed through the slit is measured. By extracting a part of spontaneously emitted light generated from the SOA chip 10 and measuring the light intensity, the amount of light received by the optical power meter 31 (that is, the position of the input side lens 13 and the output side lens 14 is changed). Thus, it is possible to check the fluctuation of the light intensity of the spontaneous emission light measured by the optical power meter 31, and the position adjustment of the input side lens 13 and the output side lens 14 can be performed with high accuracy.

  Thereafter, the positions of the input side lens 13 and the output side lens 14 are fixed. Further, another member such as an isolator is disposed in the package 16 (step S4: lens position fixing step).

  Next, one end side of the input side optical fiber 11 is temporarily arranged at a position where it is optically coupled to the light incident end face 10 a of the SOA chip 10 via the isolator 24 and the input side lens 13. Further, one end side of the output side optical fiber 12 is temporarily arranged at a position where it is optically coupled to the light emitting end face 10b of the SOA chip 10 via the output side lens 14 (step S5: optical fiber temporary arrangement step).

  Next, the other end of the input side optical fiber 11 is connected to a signal light source 30 that generates non-polarized light as signal light. For example, the signal light source 30 can be an SOA that generates non-polarized spontaneous emission light. In this case, the configuration of the signal light source can be simplified. Alternatively, the signal light source 30 may include a light emitting element such as a semiconductor laser or a super luminescent diode and a depolarizer that converts the polarization state of the light output from the light emitting element into non-polarized light. Good. For example, when a super luminescent diode is used as the light emitting element and a panda fiber is used as the depolarizer, there is an advantage that the length of the panda fiber necessary for depolarization is about 10 μm. Further, the other end side of the output side optical fiber 12 is connected to the optical power meter 31 that measures the light intensity of the amplified signal light or spontaneous emission light output from the light emitting end face 10b of the SOA chip 10 (step S6). .

  Other examples of the signal light source 30 include a light emitting diode (LED) and an optical fiber amplifier in which excitation light is incident but no signal light is incident. Alternatively, the signal light source 30 may have a configuration in which the polarization planes of the stimulated emission light generated from the two LD light sources are orthogonal to each other by a polarizer, and two lights having the orthogonal polarization planes are combined and output by a polarization coupler. .

  In the state where the drive current is supplied to the SOA chip 10, spontaneous emission light is generated from the SOA chip 10. However, since the isolator 24 is disposed on the input side of the SOA chip 10, the spontaneous emission light is input. The light does not enter the side optical fiber 11 and enters only the output side optical fiber 12.

  Next, one end side of the output side optical fiber 12 is fixed at a position where the light intensity of the spontaneous emission light measured by the optical power meter 31 becomes maximum (step S7: output side optical fiber position fixing step). That is, the output-side optical fiber 12 having the ferrule 26b attached to the tip is aligned with the SOA chip 10 so that the optical coupling rate between the SOA chip 10 and the output-side optical fiber 12 is maximized. In this state, the sleeve 27b and the ferrule 26b are fixed by welding.

  Next, the signal light from the signal light source 30 is input from the other end side of the input side optical fiber 11 and transmitted toward the one end side (step S8: input side optical fiber position fixing step). As a result, the signal light passes through the isolator 24, is amplified by the SOA chip 10, and then enters the output-side optical fiber 12.

  Next, with the signal light being input to the SOA chip 10, one end side of the input side optical fiber 11 is fixed at a position where the light intensity of the amplified signal light measured by the optical power meter 31 is maximized. (Step S9: Input side optical fiber position fixing step). That is, the input side optical fiber 11 with the ferrule 26a attached to the tip is aligned with the SOA chip 10 so that the optical coupling rate between the SOA chip 10 and the input side optical fiber 11 is maximized. In this state, the sleeve 27a and the ferrule 26a are fixed by welding.

  Next, the covers 28a and 28b are welded and fixed to the wall surfaces 16a and 16b of the package 16, respectively, and module sealing or the like is performed to complete the SOA module 1 of the present embodiment.

  Note that the fixing of the input side lens 13 and the output side lens 14 performed in step S4 may be performed after the fixing of the output side optical fiber 12 in step S7 or the fixing of the input side optical fiber 11 in step S9.

  As described above, the method for manufacturing the SOA module 1 according to the present embodiment is performed on the SOA module 1 in which the isolator 24 is disposed between the input side optical fiber 11 and the SOA chip 10. . According to the manufacturing method of this embodiment, even when the environment around the input side optical fiber 11 is changed by inputting non-polarized signal light to the input side optical fiber 11, the polarization of the SOA chip 10 is changed. It is possible to perform stable alignment with respect to the input side optical fiber 11 by suppressing a change in the light intensity of the amplified signal light due to the wave dependency.

  Moreover, the manufacturing method of the SOA module 1 according to the present embodiment can perform alignment using the spontaneous emission light emitted from the SOA chip 10 for the output side optical fiber 12.

  In addition, in the method for manufacturing the SOA module 1 according to the present embodiment, the input side lens 13 and the input side optical fiber 11 and the output side optical fiber 12 are not disposed between the signal light source 30 and the optical power meter 31. In addition, the position of the output side lens 14 can be optimized.

  In addition, in the method for manufacturing the SOA module 1 according to the present embodiment, the input side lens 13 and the output side lens 14 that have been adjusted in the lens position adjustment step are input between the signal light source 30 and the optical power meter 31. The fiber 11 and the output side optical fiber 12 can be fixed without being arranged.

1 SOA module (semiconductor optical amplifier module)
10 SOA chip (semiconductor optical amplifier)
DESCRIPTION OF SYMBOLS 10a Light incident end surface 10b Light output end surface 11 Input side optical fiber 12 Output side optical fiber 13 Input side lens 14 Output side lens 17, 17a, 17b Terminal 24 Isolator 30 Signal light source 31 Optical power meter (light intensity measuring device)

Claims (4)

A semiconductor optical amplifier (10) for amplifying the input signal light;
An input side optical fiber (11) for inputting the signal light to the semiconductor optical amplifier;
An output side optical fiber (12) for transmitting the amplified signal light or spontaneous emission light output from the semiconductor optical amplifier to the outside;
An input side lens (13) for condensing the signal light output from one end side of the input side optical fiber toward the light incident end face (10a) of the semiconductor optical amplifier;
An output side lens (14) for condensing the amplified signal light or spontaneous emission light output from the light emitting end face (10b) of the semiconductor optical amplifier toward one end side of the output side optical fiber;
A semiconductor optical amplifier module (1), comprising: an isolator (24) disposed between one end side of the input side optical fiber and the input side lens and blocking light from the semiconductor optical amplifier to the input side optical fiber. ) Manufacturing method,
A drive current supply step (S2) for starting supply of drive current to the semiconductor optical amplifier to generate spontaneous emission light from the semiconductor optical amplifier;
One end side of the input side optical fiber is temporarily disposed at a position where it is optically coupled to the light incident end surface of the semiconductor optical amplifier via the isolator and the input side lens, and one end side of the output side optical fiber is Temporary optical fiber placement step (S5) for temporary placement at a position optically coupled to the light emitting end face of the semiconductor optical amplifier via the output side lens;
The amplified signal output from the light emitting end face of the semiconductor optical amplifier while connecting the other end of the input-side optical fiber to a signal light source (30) that generates unpolarized light as the signal light Connecting the other end of the output side optical fiber to a light intensity measuring device (31) for measuring the light intensity of light or spontaneous emission light (S6);
The signal light from the signal light source is transmitted from the other end side of the input side optical fiber toward the one end side, and measured by the light intensity measuring device in a state where the signal light is input to the semiconductor optical amplifier. And an input side optical fiber position fixing step (S8, S9) for fixing one end side of the input side optical fiber at a position where the light intensity of the amplified signal light is maximized. Manufacturing method of optical amplifier module.   Before the input side optical fiber position fixing step, the output side optical fiber position fixing for fixing one end side of the output side optical fiber at a position where the light intensity of the spontaneous emission light measured by the light intensity measuring device is maximized. The method of manufacturing a semiconductor optical amplifier module according to claim 1, further comprising a step (S7).   3. The semiconductor according to claim 1, further comprising a lens position fixing step (S <b> 4) for fixing the positions of the input side lens and the output side lens before the optical fiber provisional placement step. Manufacturing method of optical amplifier module. Before the lens position fixing step, further includes a lens position adjusting step (S3) for adjusting the positions of the input side lens and the output side lens using spontaneous emission light generated from the semiconductor optical amplifier,
In the lens position adjusting step, the light intensity of the spontaneous emission light generated from the semiconductor optical amplifier that has passed through the slit is measured by the light intensity measuring device, and based on the fluctuation of the light intensity measured by the light intensity measuring device. The position of the input side lens and the output side lens is adjusted by confirming position fluctuations of the input side lens and the output side lens, according to any one of claims 1 to 3. The manufacturing method of the semiconductor optical amplifier module of description.

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