JP2010145767A - Optical module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical module which partially changes the property of a transparent resin and whose cost is made low, which shortens adjustment time for adjusting an optical axis and time for assembling it and which enhances optical coupling efficiency. <P>SOLUTION: In the optical module, a semiconductor laser and an optical waveguide are optically coupled to each other. The optical module includes: a transparent resin arranged at least in one end of the optical waveguide; and a core part provided in the transparent resin, the core part being formed by changing the property of the transparent resin by irradiating it with light having a specific wavelength corresponding to an optical path, wherein the transparent resin and the semiconductor laser are arranged away from each other. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical module.

An optical module using a semiconductor laser and an optical fiber has been developed for optical signal transmission, for example. Various methods have been proposed in the past for optically coupling outgoing light output from a semiconductor laser to an optical fiber in an optical module. For example, a method of condensing outgoing light using a condensing means such as a lens and optically coupling it to an optical fiber, a method of bringing an end face of an optical fiber close to the outgoing end face of a semiconductor laser, and the like have been proposed.

As a method using a condensing means, in Patent Document 1, an LD assembly is configured by mounting a semiconductor laser array and a lens array on a metal block, and the LD assembly is accommodated and sealed in a package having a window on the side wall. A semiconductor laser module is proposed in which an optical fiber array attached to the outside of an LD and an LD assembly are optically coupled, and a metal block is laser welded to the inner side surface of the side wall of the package. ing.
JP-A-6-308358

However, in the method using the condensing means as described above, it is necessary to align the semiconductor laser, the condensing means, and the optical fiber with the respective optical axes at the same time.

Therefore, the present inventor optically couples the light generated by the semiconductor laser to the end of the optical waveguide without using a lens, and partially couples the light between the semiconductor laser and the optical waveguide. The transparent resin is disposed on the surface, and the transparent resin is partially altered to form an optical waveguide for guiding the emitted light of the semiconductor laser to the optical waveguide, thereby reducing the cost and adjusting time for adjusting the optical axis. An object of the present invention is to provide an optical module that can shorten the assembly time and increase the optical coupling efficiency.

An optical module according to a first aspect of the present invention is an optical module in which a semiconductor laser and an optical waveguide are optically coupled, and includes a transparent resin disposed at at least one end of the optical waveguide, and the transparent resin And a core portion formed by applying light of a specific wavelength corresponding to an optical path, wherein the transparent resin and the semiconductor laser are arranged separately.

The optical module according to a second aspect of the present invention is characterized in that the core portion has a tapered shape so that the optical waveguide side becomes thinner.

The optical module according to a third aspect of the present invention is characterized in that an isolator is disposed at one end of the transparent resin opposite to the optical waveguide.

The optical module according to a fourth aspect of the present invention is characterized in that an isolator is disposed between the transparent resin and the optical waveguide.

An optical module according to a fifth aspect of the present invention is disposed on the optical path of the optical waveguide, and reflects a light reflecting part that reflects light coming from the opposite side of the semiconductor laser, and a ferrule disposed on the outer periphery of the optical waveguide. And the ferrule is formed with a passage port through which the light reflected from the light reflecting portion passes.

The optical module according to a sixth aspect of the present invention is characterized in that the light reflecting portion is formed on the end face of the optical waveguide by vapor deposition.

In the optical module according to the seventh aspect of the present invention, the passage has a two-stage structure of an outer hole formed outside the ferrule and an inner hole formed smaller than the outer hole. Features.

The optical module according to an eighth aspect of the present invention is characterized in that the ferrule is disposed so as to cover more than half of the outer periphery of the optical waveguide.

As described above, according to the present invention, the transparent resin is disposed in a part between the semiconductor laser and the optical waveguide, and the transparent resin is partially altered to guide the emitted light of the semiconductor laser to the optical fiber. By forming the optical waveguide, the adjustment time for adjusting the optical axis and the assembly time can be shortened and the optical coupling efficiency can be increased.

An embodiment of the present invention will be described with reference to the drawings. In addition, the embodiment described below is for explanation, and does not limit the scope of the present invention. Accordingly, those skilled in the art can employ embodiments in which each or all of these elements are replaced by equivalents thereof, and these embodiments are also included in the scope of the present invention.
In addition, about each component which has the same function, the same code | symbol is attached | subjected and shown for simplification of illustration and description.

An optical module according to a first embodiment of the present invention will be described below with reference to FIGS. 1 to 3 are sectional views of the optical module. Hereinafter, an optical fiber will be described as an example of the optical waveguide.

The optical module 100 of FIG. 1 is mainly configured as a transmitter. An optical fiber 102 is disposed inside a ferrule 101, and an optical transmission module 106 is disposed so that light is incident on a core portion 102b of the optical fiber 102. Yes. The optical transmission module 106 has a substrate 109 disposed therein, and an optical element 108 is mounted on the substrate 109. Then, the optical transmission module 106 causes the optical element 108 to emit light by passing an electric current through the optical element 108, and condenses the emitted light by the condensing lens 107 arranged at the emission part of the optical transmission module. ing.

A transparent resin 103 is disposed on one end side of the optical fiber 102, and the transparent resin 103 is altered so that a portion corresponding to the optical path has a taber shape as the core portion 104. An isolator 105 that blocks the return light is disposed between the transparent resin 103 and the optical transmission module 106. The transparent resin 103 and the optical transmission module 106 are arranged at a certain distance.

The transparent resin 103 and the core part 104 are made of the same material, and the refractive index of the transparent resin 103 is changed by irradiating, for example, light having a wavelength of 1.27 μm to the part to be changed into the core part as an optical path. The core portion 104 is formed.

By changing the refractive index in this way, light emitted from the optical transmission module can be confined in the core portion 104, and the optical coupling efficiency between the optical transmission module 106 and the optical fiber 102 can be improved. . Furthermore, since it can be manufactured by simply irradiating light after disposing a transparent resin at the end of the optical fiber, the manufacturing cost can be reduced.

Since the transparent resin 103 and the optical transmission module 106 are arranged at a certain distance, the condensing lens 107 arranged at the emission part of the optical transmission module 106 is not in direct contact with the transparent resin 103. On the other hand, if the condensing lens 107 and the transparent resin 103 are in direct contact with each other, the refractive index of the space and the transparent resin 103 is different, so that the shape of the condensing lens 107 is also adapted to the transparent resin 103. Therefore, the condenser lens 107 that has been conventionally used cannot be used.

Accordingly, since the transparent resin 103 and the optical transmission module 106 are arranged at a certain distance, the conventional optical transmission module 106 having the condensing lens 107 can be used, so that the cost can be reduced. It becomes possible.

  Next, the optical module 100 shown in FIG. 2 is different from FIG. 1 in that the isolator 105 is in contact with the transparent resin 103. At this time, the isolator 105 can be bonded and fixed by providing the transparent resin 103 or the core portion 104 itself with an adhesive function.

  By making the isolator 105 in contact with the transparent resin 103 in this way, the manufacturing process of fixing the isolator 105 can be simplified, and high optical coupling efficiency between the optical transmission module 106 and the optical fiber 102 can be realized. Become.

Next, the optical module 100 shown in FIG. 3 is different from FIGS. 1 and 2 in that the isolator 105 is disposed between the optical fiber 102 and the transparent resin 103. At this time, the isolator 105 can be bonded and fixed by providing the transparent resin 103 or the core portion 104 itself with an adhesive function.

By arranging the isolator 105 between the optical fiber 102 and the transparent resin 103 in this way, the manufacturing process of fixing the isolator 105 is simplified, and high optical coupling efficiency between the optical transmission module 106 and the optical fiber 102 is realized. It becomes possible.

Moreover, about the optical module of FIGS. 1-3 mentioned above, the reflected light in the connection point of the optical fiber 102 and the core part 104 can also be suppressed by forming the end surface of the side which arrange | positions the transparent resin 103 diagonally. Is possible.

An optical module according to the second embodiment of the present invention will be described below with reference to FIGS. 4 to 6 are cross-sectional views of the optical module.

The optical module 200 of FIG. 4 is mainly configured as a transceiver, and an end portion where the transparent resin 103 of the optical fiber 102 is disposed between the transparent resin 103 of the optical module 100 and the isolator 105 described in FIG. Is provided with an optical filter 205 for reflecting the received light coming from the opposite end. The reception light reflected by the optical filter 205 is received by the optical reception module 206 via the condenser lens 207.

The optical module 300 in FIG. 5 has a transceiver configuration as in FIG.
That is, the optical filter 205 is disposed between the optical fiber 102 and the optical fiber 302 disposed inside the ferrule 101. A pass opening 301 through which the received light reflected by the optical filter 205 passes is formed in the ferrule 101. The passage port 301 can be formed by polishing the ferrule 101 or the like. As the material of the ferrule, alumina or glass excellent in workability is preferable.

Furthermore, the optical filter 205 is desirably formed by vapor deposition on the end face of the end portion of the optical fiber 102 or the optical fiber 302. Since the optical fiber with the optical filter 205 deposited on the end face is simply inserted into the ferrule 101, the manufacturing process can be simplified easily.

By arranging the optical filter 205 between the optical fiber 102 and the optical fiber 302 in this way, the manufacturing process of fixing the optical filter 205 is simplified, and high optical coupling efficiency between the optical transmission module 106 and the optical fiber 302 is increased. High optical coupling efficiency between the optical receiving module 206 and the optical fiber 102 can be realized while realizing it.

Next, the optical module 300 of FIG. 6 is different from FIG. 5 in that the passage port 401 has a two-stage structure. A transparent resin 403 is disposed in a portion of the passage port 401 having a two-stage structure that is in contact with the portion of the optical fiber 102.
In addition, the optical fiber 302 can have a high confinement effect by using a bending fiber that is resistant to bending.

As described above, since the passage opening 401 has a two-stage structure, the outer peripheral portion of the two-stage structure is cut roughly and broadly, and only the immediate vicinity of the optical fiber 102 is cut with high accuracy, thereby simplifying the manufacturing process. In addition, by disposing the transparent resin 403 in a portion in contact with the optical fiber 102, it is possible to realize high optical coupling efficiency between the optical receiving module 206 and the optical fiber 102 by the lens effect of the transparent resin 403. .

The structure of the passage openings 301 and 401 in FIGS. 5 and 6 described above will be described with reference to FIGS. 7A is a cross-sectional view of the ferrule 101 of FIG. 5 as viewed from the longitudinal direction, and FIG. 7B is a cross-sectional view of the AA ′ portion of FIG. 7A. 8A is a cross-sectional view of the ferrule 101 of FIG. 6 viewed from the longitudinal direction, and FIG. 8B is a cross-sectional view of the BB ′ portion of FIG. 8A.

7B to FIG. 5 is formed so that the ferrule 101 covers more than half of the outer periphery of the optical fiber 102.
8B to 6 are formed so that the ferrule 101 covers more than half of the outer periphery of the optical fiber 102, and the passage port 401 is formed in a two-stage structure.
Thus, since the ferrule 101 is formed so as to cover more than half of the outer periphery of the optical fiber 102, the optical fiber 102 is dropped from the ferrule 101 even in the manufacturing process after the optical fiber 102 is inserted into the ferrule 101. Can be prevented.

Next, the manufacturing method of the optical fiber which has arrange | positioned the transparent resin of the optical module of this invention is demonstrated below using FIG.

In FIG. 9A, first, a connector 500 in which an optical fiber 502 is disposed inside a ferrule 501 is prepared. Then, the transparent resin 503 prepared in advance is applied to the end surface of the connector 500 by the resin coating device 510. Note that a silicone resin was used as the transparent resin 503.

In FIG. 9B, the transparent resin 503 applied to the end surface of the connector 500 is cured. About the conditions to harden | cure, what is suitable for the transparent resin 503 to be used is used. As one condition for curing the silicone resin, the silicone resin was cured by leaving it in an atmosphere of 150 ° C. for 1 hour.

In FIG. 9C, the laser light source 520 is used to irradiate light having a wavelength of 1.27 μm toward the transparent resin 503 cured in FIG. 9B. At this time, a portion that is irradiated with light having a wavelength of 1.27 μm is transformed into the core portion 504, whereby an optical path is formed. About the conditions to change in quality, it implements on the conditions suitable for the transparent resin 503 to be used. In addition, as conditions for changing the quality of the core portion 504, the light output of the laser light source 520 was set to 10 mW, and the transparent resin 503 was irradiated for 8 hours.

By irradiating light under such conditions, the crosslink density of Si in the silicone resin is increased, and the refractive index of the portion irradiated with light is changed to form an optical waveguide. The adjustment of the optical axis when forming the core portion 504 can be easily realized by fixing the connector 500 using a split sleeve (not shown).

Next, another method for manufacturing an optical fiber in which a transparent resin is arranged will be described with reference to FIG. Note that FIGS. 10A and 10B are the same steps as FIGS. 9A and 9B, and a description thereof will be omitted.

10C, a laser light source 520 is used to irradiate light having a wavelength of 1.27 μm from the opposite end surface of the connector 500 on which the transparent resin 503 cured in FIG. 10B is disposed. At this time, a portion that is irradiated with light having a wavelength of 1.27 μm is transformed into the core portion 504, whereby an optical path is formed. Regarding the condition for alteration, as the condition for altering the core portion 504, the light output of the laser light source 520 was set to 10 mW, and the transparent resin 503 was irradiated for 12 hours.

By irradiating light under such conditions, the crosslink density of Si in the silicone resin is increased, and the refractive index of the portion irradiated with light is changed to form an optical waveguide. Further, since the core portion 504 formed in this way has a diameter substantially the same as the core diameter of the optical fiber 502, the reflected light at the connection point between the optical fiber 502 and the core portion 504 is suppressed. It is also possible.

The irradiation conditions of the emitted light from the laser light source 520 described above include at least the wavelength of the emitted light and the irradiation time of the emitted light. In addition, the wavelength of the emitted light and the ambient temperature are adjusted so that the wavelength in the wavelength region including at least the wavelength region that activates oxygen in the atmosphere including at least oxygen molecules.

This is because the oxygen in the atmosphere is activated by the energy of the emitted light when the wavelength of the emitted light from the laser light source 520 is a wavelength region in which oxygen is in a singlet excited state (a wavelength region of 1.2687 μm or less). That is, this is because the triplet excited state is changed to the singlet excited state and reacts with a methyl resin silicone resin having a methyl group in the side chain.

That is, in a silicone resin, oxygen is activated (from a triplet state to a singlet state), and in some cases, a radical reaction occurs to cut a low molecular side chain such as a methyl group and polymerize the main chain. It is.

FIG. 11 is a view for explaining the alteration mechanism of a methyl resin-based silicone resin.
As shown in FIG. 11, when an emitted light having a wavelength satisfying a wavelength region of 1.2687 μm or less is output from a laser light source 520 to a methyl resin silicone resin (state 1) having a methyl group in a side chain in an oxygen atmosphere. The side chain which is a methyl group is cut and bonded to oxygen in a singlet excited state (state 2), and the main chain is polymerized (state 3).
Further, the transparent resin 503 is not limited to the silicone resin, and can be applied to other resins as long as the refractive index of the resin is changed by light irradiation.

It is sectional drawing of the optical module of basic embodiment of this invention. It is sectional drawing of the optical module of embodiment of the modification of FIG. It is sectional drawing of the optical module of embodiment of the modification of FIG. It is sectional drawing of the optical module of basic embodiment of this invention. It is sectional drawing of the optical module of embodiment of the modification of FIG. It is sectional drawing of the optical module of embodiment of the modification of FIG. It is sectional drawing of the ferrule shown in FIG. It is sectional drawing of the ferrule shown in FIG. It is the manufacturing method of the optical fiber which has arrange | positioned the transparent resin of embodiment of this invention. It is the manufacturing method of the optical fiber which has arrange | positioned the transparent resin of embodiment of this invention. It is a figure for demonstrating the alteration mechanism of a methylresin type silicone tree seed | species.

Explanation of symbols

100, 200, 300, 400 Optical module 500 Connector
101, 501 Ferrule 102, 302, 502 Optical fiber 103, 403, 503 Transparent resin 104, 504 Core part 105 Isolator 106 Optical transmission module 107, 207 Condensing lens 108 Optical element 109 Substrate 205, 305 Optical filter 206 Optical reception module 301 401 passage

Claims (8)

An optical module in which a semiconductor laser and an optical waveguide are optically coupled,
A transparent resin disposed on at least one end of the optical waveguide;
The transparent resin comprises a core portion formed by applying light of a specific wavelength corresponding to the optical path,
The optical module, wherein the transparent resin and the semiconductor laser are arranged separately. The optical module according to claim 1, wherein the core portion has a tapered shape so that the optical waveguide side becomes narrower. The optical module according to claim 1, wherein an isolator is disposed at the other end of the transparent resin. The optical module according to claim 1, wherein an isolator is disposed between the transparent resin and the optical waveguide. A light reflecting portion that is disposed on the optical path of the optical waveguide and reflects light coming from the opposite side of the semiconductor laser;
A ferrule disposed on the outer periphery of the optical waveguide,
5. The optical module according to claim 1, wherein the ferrule is formed with a passage port through which light reflected from the light reflecting portion passes. The optical module according to claim 5, wherein the light reflecting portion is formed by vapor deposition on an end face of the optical waveguide. The said passage port has a two-stage structure of an outer hole formed outside the ferrule and an inner hole formed smaller than the outer hole. Optical module.   The optical module according to claim 5, wherein the ferrule is disposed so as to cover at least half of the outer periphery of the optical waveguide.

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