JPH09236724A - Optical multiplexer/demultiplexer and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the adjustment of the optical axis of a diffraction grating against an optical fiber and to improve the accuracy of wavelength separation and to reduce the transmission loss by preventing a deviation of the optical axis after the adjustment thereof in an optical mutiplexer/demultiplexer. SOLUTION: An input optical fiber 1 and output optical fibers 21, 22, 23, whose end faces 20 are obliquely ground, are fixed to a graded index lens 3, a first transparent body 81 having a convex sphericality 81a is adhered and fixed to the graded index lens 3, a second transparent body 71 having a recessed spherical surface 71a is adhered and fixed to the diffraction grating 5. The optical axis is adjusted at a state in which the convex sphericality 81a is adhered to the recessed sherical surface 71a via a resin cured by the ultraviolet rays, then the first transparent body 81 is firmly fixed to the second transparent body 71 by irradiating the adhered surface with ultraviolet rays.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wavelength division multiplexing transmission system in optical communication, an optical multiplexer / demultiplexer used in the apparatus, and a manufacturing method thereof.

[0002]

2. Description of the Related Art In optical communication, a wavelength division multiplexing optical transmission system for transmitting multi-channel signals through a single fiber is known. The wavelength division multiplexing optical transmission system is that the signal of each channel is wavelength-multiplexed by the optical multiplexer with the light of different wavelengths, transmitted from the transmitting side to the receiving side with one fiber, and the receiving side multiplexes with the optical demultiplexer. The transmitted light is separated and regenerated for each wavelength. Generally, an interference film filter, a diffraction grating, an optical waveguide, etc. are used as a wavelength separation element of an optical multiplexer / demultiplexer. In particular, for high-density wavelength-division multiplex transmission in which transmission signal light is wavelength-multiplexed at intervals of several nanometers, a diffraction grating with high resolution is used and is combined with an optical fiber, a lens or the like to form an optical multiplexer / demultiplexer.

An example of an optical multiplexer / demultiplexer conventionally used in the wavelength division multiplexing optical transmission system (a cross section of the central portion) will be described with reference to FIG. In FIG. 12, 1 is an input optical fiber, 21, 22, 23 is an output optical fiber, 3 is a gradient index lens, 5 is a diffraction grating, 7 is a prism-shaped transparent body, 4 and 6 are adhesive layers, 7a and Reference numerals 3a denote end faces of the transparent body 7 and the refractive index lens 3, respectively. When used as an optical demultiplexer, as shown in FIG. 12, for example, signals of three channels are wavelength-multiplexed with different wavelengths λ1, λ2, and λ3 and transmitted through the input optical fiber 1. The wavelength-multiplexed light is converted into parallel light by the refractive index lens 3 and is incident on the diffraction grating 5 via the prism-shaped transparent body 7. The diffraction grating 5 separates (diffracts) the incident light in different directions according to the wavelengths λ1, λ2, and λ3, and reflects it. Through the transparent body 7 and the refractive index lens 3, output optical fibers 21, 22, and 23 are provided in the diffraction directions corresponding to the respective wavelengths λ1, λ2, and λ3, and the wavelength-separated wavelengths λ1, λ2, and λ3 are provided. Light of different output optical fibers 21, 22, 23
Is transmitted inside. On the other hand, when used as an optical multiplexer,
Wavelength multiplexing is performed by the reverse principle.

When manufacturing the above-mentioned conventional optical multiplexer / demultiplexer, the diffraction grating 5 is fixed to the transparent body 7 at a predetermined inclination angle by the adhesive layer 6 in advance, and the input optical fiber 1 and the output optical fibers 21, 22, 22 are provided. Refractive index distribution lens 3 in which 23 is arranged
Is prepared, and after the optical axis is adjusted, the end faces 7a and 3a are fixed via the adhesive layer 4. As a result, it is possible to obtain an optical multiplexer / demultiplexer in which each optical component is integrated.

[0005]

In an optical multiplexer / demultiplexer using a diffraction grating, the direction of light dispersion by the diffraction grating 5 and the arrangement of the optical fibers must match. Therefore, in the above conventional optical multiplexer / demultiplexer, the rotation direction of the diffraction grating 5 (see FIG.
2), the tilt direction (direction of arrow B in FIG. 12), the rotation direction in the plane of the grating (direction of arrow C in FIG. 12), and stabilize the diffraction grating 5 at that position. However, there was a problem that it had to be fixed.

An optical multiplexer / demultiplexer using a diffraction grating has a very high resolution, but conversely, a slight shift in the optical axis or a setting error causes an increase in loss, or wavelengths at which multiplexing and demultiplexing are performed. Will be misaligned. Therefore, as in the above-mentioned conventional example, the refractive index distribution lens 3 has optical fibers 1, 21, 22,
23 and the diffraction grating 5 are attached to each other, or each component is adjusted and bonded on a flat base. In this case, since the position and angle of each component are adjusted between the flat end faces, the end faces 7a and 3a contact each other in an oblique state,
The problem is that scratches are likely to occur on the light passage surface. In order to prevent the occurrence of scratches on the light passage surface, it is necessary to provide a gap between the end faces of each other for the adjustment work. However, even after the adjustment, it is not possible to fix the transparent body 7 and the gradient index lens 3 in a state where they are in complete contact,
There is a problem that the layer thickness of the adhesive layer 4 becomes non-uniform and it is difficult to obtain stability over time after fixing.

The present invention has been made to solve the above-mentioned problems of the conventional optical multiplexer / demultiplexer, and an object thereof is to provide an optical multiplexer / demultiplexer which can be easily assembled, adjusted and fixed, and a manufacturing method thereof. To do.

[0008]

To achieve the above object, a first optical multiplexer / demultiplexer according to the present invention comprises a plurality of optical fibers for inputting and outputting a wavelength division multiplexed optical signal and a plurality of optical signals having different wavelengths. And a diffraction grating for separating the wavelength-multiplexed optical signal transmitted by the optical fiber into optical signals of respective wavelengths or wavelength-multiplexing a plurality of optical signals, and the diffraction grating for the optical signals input and output by the optical fiber. Of the refractive index distribution lens for collimating the first and the second transparent body provided on the grating surface of the diffraction grating and having a concave or concave substantially spherical surface on the side of the refractive index distribution lens; A second spherical surface provided on the diffraction grating side and having a convex or concave substantially spherical surface that is in close contact with the concave or convex substantially spherical surface of the first transparent body.
And a transparent body.

A second optical multiplexer / demultiplexer of the present invention is a plurality of optical fibers for inputting / outputting a wavelength-multiplexed optical signal and a plurality of optical signals having different wavelengths, and a wavelength-multiplexer transmitted by the optical fiber. A diffraction grating for separating an optical signal into optical signals of respective wavelengths or wavelength-multiplexing a plurality of optical signals, and a surface on the side of the diffraction grating is a convex or concave substantially spherical surface, which is input and output by the optical fiber. A refractive index distribution lens for collimating an optical signal to the diffraction grating, and a surface on the side of the refractive index distribution lens, which is provided on the grating surface of the diffraction grating, is the convex or concave substantially spherical surface of the refractive index distribution lens. The transparent body is a concave or convex substantially spherical surface that is in close contact with the transparent body.

Further, the third optical multiplexer / demultiplexer of the present invention has a plurality of optical fibers for inputting and outputting a wavelength division multiplexed optical signal and a plurality of optical signals having different wavelengths, and a diffraction grating is formed on one end face thereof. A diffraction element that separates the wavelength-multiplexed optical signal transmitted by the optical fiber into optical signals of respective wavelengths or wavelength-multiplexes a plurality of optical signals, and the other end surface is a concave or convex substantially spherical surface. A gradient index lens for collimating an optical signal input and output by an optical fiber to the diffractive element, and a refractive index distribution lens provided on the diffractive element side of the diffractive element, and closely attached to the concave or convex substantially spherical surface of the diffractive element. And a transparent body having a convex or concave substantially spherical surface.

The fourth optical multiplexer / demultiplexer of the present invention has a plurality of optical fibers for inputting / outputting a wavelength-multiplexed optical signal and a plurality of optical signals having different wavelengths, and a diffraction grating formed on one end face thereof. A diffraction element that separates the wavelength-multiplexed optical signal transmitted by the optical fiber into optical signals of respective wavelengths or wavelength-multiplexes a plurality of optical signals, and the other end surface is a concave or convex substantially spherical surface. The end surface on the side of the diffractive element is a convex or concave substantially spherical surface in close contact with the concave or convex substantially spherical surface of the diffractive element, and a refractive index for collimating an optical signal input / output by the optical fiber to the diffractive element. And a distribution lens.

In the first to fourth optical multiplexers / demultiplexers,
It is preferable that the concave substantially spherical surface and the convex substantially spherical surface have the same radius of curvature. Further, it is preferable to polish or cut the end face of the optical fiber and the end face of the gradient index lens in contact with the end face of the optical fiber obliquely with respect to the optical axis.

In the first optical multiplexer / demultiplexer, it is preferable that the first optical multiplexer / demultiplexer further comprises a housing having an internal space capable of accommodating at least the diffraction grating and the second transparent body so as not to contact the inner wall thereof. The second optical multiplexer / demultiplexer preferably includes a housing having an internal space that can house at least the diffraction grating and the transparent body so as not to contact the inner wall thereof. Further, in the third or fourth optical multiplexer / demultiplexer, it is preferable to include a housing having an internal space capable of accommodating at least the diffraction element so as not to contact the inner wall thereof.

On the other hand, the first method of manufacturing an optical multiplexer / demultiplexer according to the present invention includes a plurality of optical fibers for inputting and outputting a wavelength-division-multiplexed optical signal and a plurality of optical signals having different wavelengths, and the optical fibers for transmission. And a diffraction grating for separating the wavelength-multiplexed optical signal into optical signals of respective wavelengths or wavelength-multiplexing a plurality of optical signals, and a refractive index distribution lens for collimating the optical signals input / output by the optical fiber to the diffraction grating. A method of manufacturing an optical multiplexer / demultiplexer comprising: providing a first transparent body having a concave or convex substantially spherical surface on a side of the gradient index lens on a grating surface of the diffraction grating, A second transparent body having a convex or concave substantially spherical surface that is in close contact with the concave or convex substantially spherical surface of the first transparent body is provided on the diffraction grating side of the factor distribution lens, and the concave substantially spherical surface and the UV-cured tree between convex spherical surfaces Filling the performs optical axis adjustment in close contact with each other, after the optical axis adjustment ends to fix the ultraviolet rays irradiated to the contact portion of the substantially spherical and convex substantially spherical surface of the concave.

A second method of manufacturing an optical multiplexer / demultiplexer according to the present invention includes a plurality of optical fibers for inputting / outputting a wavelength-multiplexed optical signal and a plurality of optical signals having different wavelengths, and the optical fibers for transmission. And a diffraction grating for separating the wavelength-multiplexed optical signal into optical signals of respective wavelengths or wavelength-multiplexing a plurality of optical signals, and a refractive index distribution lens for collimating the optical signals input / output by the optical fiber to the diffraction grating. In the method of manufacturing an optical multiplexer / demultiplexer, the surface of the gradient index lens on the side of the diffraction grating is formed into a convex or concave substantially spherical surface, and the refractive index distribution is formed on the grating surface of the diffraction grating. A lens-side surface is provided with a transparent body that is a concave or convex substantially spherical surface that comes into close contact with the convex or concave substantially spherical surface of the gradient index lens, and between the concave substantially spherical surface and the convex substantially spherical surface. Filled with UV curable resin, Perform optical axis adjustment in close contact you are, after optical axis adjustment ends to fix the ultraviolet rays irradiated to the contact portion of the substantially spherical and convex substantially spherical surface of the concave.

The third method of manufacturing an optical multiplexer / demultiplexer according to the present invention includes a plurality of optical fibers for inputting and outputting a wavelength division multiplexed optical signal and a plurality of optical signals having different wavelengths, and the optical fibers transmitting the optical signals. And a diffractive element that separates the wavelength-multiplexed optical signal into optical signals of respective wavelengths or wavelength-multiplexes a plurality of optical signals, and a refractive index distribution lens that collimates the optical signals input and output by the optical fiber to the diffractive element. In the method of manufacturing an optical multiplexer / demultiplexer, the diffraction grating is formed on one end face of the diffraction element, and the other end face forms a concave or convex substantially spherical surface, and On the diffractive element side, a transparent body having a convex or concave substantially spherical surface that adheres to the concave or convex substantially spherical surface of the diffractive element is provided, and ultraviolet curing is performed between the concave substantially spherical surface and the convex substantially spherical surface. Fill the resin and Perform optical axis adjustment in wearing condition, after the optical axis adjustment ends to fix the ultraviolet rays irradiated to the contact portion of the substantially spherical and convex substantially spherical surface of the concave.

Further, a fourth method of manufacturing an optical multiplexer / demultiplexer according to the present invention is provided with a plurality of optical fibers for inputting and outputting a wavelength division multiplexed optical signal and a plurality of optical signals having different wavelengths, and the optical fibers for transmission. And a diffractive element that separates the wavelength-multiplexed optical signal into optical signals of respective wavelengths or wavelength-multiplexes a plurality of optical signals, and a refractive index distribution lens that collimates the optical signals input and output by the optical fiber to the diffractive element In the method of manufacturing an optical multiplexer / demultiplexer, the diffraction grating is formed on one end face of the diffraction element, and the other end face forms a concave or convex substantially spherical surface, and The end face on the side of the diffractive element is formed into a convex or concave substantially spherical surface that adheres to the concave or convex substantially spherical surface of the diffractive element, and an ultraviolet curable resin is provided between the concave substantially spherical surface and the convex substantially spherical surface. Filled and stick to each other State perform optical axis adjustment, after the optical axis adjustment ends to fix the ultraviolet rays irradiated to the contact portion of the substantially spherical and convex substantially spherical surface of the concave.

In the first method of manufacturing the optical multiplexer / demultiplexer, it is preferable that the first and second transparent bodies are formed by pressing with a die having an opposite phase of its shape. Further, in the above-mentioned second method of manufacturing the optical multiplexer / demultiplexer, it is preferable that the transparent body is formed by press working with a mold having an opposite phase of its shape. In the third or fourth optical multiplexer / demultiplexer manufacturing method, it is preferable that the diffractive element is formed by pressing with a mold having an opposite phase of its shape.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) A first embodiment of the optical multiplexer / demultiplexer and the manufacturing method thereof according to the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is a cross-sectional view showing a configuration example of a first embodiment of an optical multiplexer / demultiplexer of the present invention, and FIG. 2 is a process diagram showing a method of manufacturing the optical multiplexer / demultiplexer. Further, FIG. 3 is a cross-sectional view showing another configuration example of the first embodiment.

The optical multiplexer / demultiplexer shown in FIG. 1 has an input optical fiber 1 and, for example, three output optical fibers 21, 22, 23.
A gradient index lens 3 that plays the role of a collimator lens, and a first transparent lens 81a that is provided on one end 3a side of the gradient index lens 3 and has one convex surface (a convex spherical surface) 81a. A body 81, a second transparent body 71 having a concave substantially spherical surface (hereinafter referred to as a concave spherical surface) 71a facing the convex spherical surface 81a, and a plane linear diffraction grating (hereinafter referred to as a diffraction grating).
5 and the adhesive layer 6 for fixing the second transparent body 71 and the diffraction grating 5 to each other.

Of the two end faces 3a, 3b of the gradient index lens 3, at least the input / output optical fibers 1, 22, 22, 2 are provided.
The end surface 3b on the 3 side is polished obliquely with respect to the optical axis.
Further, the convex spherical surface 81a of the first transparent body 81 and the concave spherical surface 71a of the second transparent body 71 have substantially the same radius of curvature. The end faces 20 of the input optical fiber 1 and the output optical fibers 21, 22, 23 are also obliquely polished and fixed to 3 on the gradient index lens. The first transparent body 81 is closely fixed to one end 3a of the refractive index lens 3, and the first transparent body 81 and the second transparent body 71 are adjusted in a state where the convex spherical surface 81a and the concave spherical surface 71a are in close contact with each other. It has been fixed.

Next, the operation when the optical multiplexer / demultiplexer having the above-mentioned configuration is used as an optical demultiplexer will be described. The operation when used as an optical multiplexer may be considered by reversing the traveling direction of light. For example, three-channel signals are wavelength-multiplexed with lights having different wavelengths λ1, λ2, and λ3, and the signals are transmitted through the input optical fiber 1. The wavelength-multiplexed light becomes parallel light by the gradient index lens 3 and enters the diffraction grating 5 via the first transparent body 81 and the second transparent body 71. The diffraction grating 5 separates (diffracts) the incident light in different directions according to the wavelengths λ1, λ2, and λ3, and reflects it. The diffracted lights of the respective wavelengths λ1, λ2, λ3 are returned to the second light again.
Is collected by the gradient index lens 3 via the transparent body 71 and the first transparent body 81 of the output optical fibers 21 and 2, respectively.
Wavelengths λ1, λ2, λ separated by wavelength
The three lights are different output optical fibers 21, 22,
It transmits in 23.

Next, FIG. 2 shows a method of manufacturing the optical multiplexer / demultiplexer according to the first embodiment. As shown in (a) of FIG.
The input optical fiber 1, the output optical fibers 21, 22, and 23, the gradient index lens 3, the diffraction grating 5, the first transparent body 81, and the second transparent body 71 which are molded in a predetermined shape in advance are prepared. In particular, the first transparent body 81 and the second transparent body 71 are formed by pressing an optical material such as glass by using a mold having an inverse shape thereof. Next, (b)
First, the diffraction grating 5 and the second transparent body 71 are bonded and fixed by the adhesive layer 6 as shown in FIG. Further, the first transparent body 81, the input optical fiber 1, and the output optical fibers 21, 22, 23
Are arranged at both ends of the gradient index lens 3 and fixed. In this step, no particular strict optical axis adjustment is required except that the output optical fibers 21, 22, 23 are linearly arranged and fixed together with the input optical fiber 1 near the optical axis of the gradient index lens 3.

Next, as shown in (c), the concave spherical surface 71a of the second transparent body 71 and the convex spherical surface 81a of the first transparent body 81.
In the state in which the ultraviolet curable resin having lubricity is applied between and, the optical axes are adjusted by abutting the second transparent body 71 and the first transparent body 81 against each other while applying a force to press them against each other. At this time, since the concave spherical surface 71a and the convex spherical surface 81a have substantially the same radius of curvature, the end surfaces thereof are in close contact with each other. Therefore, with respect to the diffraction grating 5, a wavelength dispersion direction (direction of arrow A in the drawing), a tilt direction (direction of arrow B in the drawing), and a rotation direction in the grating plane (direction of arrow C in the drawing).
Even when the three axes are adjusted, the second transparent body 71 and the first transparent body 81 are always in close contact with each other. In this way, the optical axes of the signal lights of the wavelengths λ1, λ2, and λ3 from the input optical fiber 1 are wavelength-separated by the diffraction grating 5 and are coupled to the output optical fibers 21, 22, and 23, respectively. After the optical axis is adjusted, the contact portion between the concave spherical surface 71a and the convex spherical surface 81a is irradiated with ultraviolet rays to cure the ultraviolet curable resin and bond the first transparent body 81 and the second transparent body 71.

Next, another example of the configuration of the first embodiment is shown in FIG. The optical multiplexer / demultiplexer shown in FIG. 3 is different from the optical multiplexer / demultiplexer shown in FIG. 1 in that the surfaces 81a and 71a of the first transparent body 81 and the second transparent body 71, which are in close contact with each other, have opposite concavities and convexities. There are some differences. It goes without saying that the same effect can be obtained even if the concavities and convexities of the surfaces 81a and 71a that are in close contact with each other are reversed.

(Second Embodiment) Next, a second embodiment of the optical multiplexer / demultiplexer and the manufacturing method thereof according to the present invention will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 4 is a cross-sectional view showing a structural example of the second embodiment of the optical multiplexer / demultiplexer of the present invention, and FIG. 5 is a process drawing showing the manufacturing method thereof. Further, FIG. 6 is a cross-sectional view showing another configuration example of the second embodiment.

The optical multiplexer / demultiplexer shown in FIG. 4 has an input optical fiber 1 and, for example, three output optical fibers 21, 22, 23.
And a substantially spherical surface with one convex surface (hereinafter referred to as a convex spherical surface) 31a
And a transparent body 71 having a refractive index distribution lens 31 serving as a collimating lens, a concave substantially spherical surface (hereinafter, referred to as a concave spherical surface) 71a facing the convex spherical surface 31a of the refractive index distribution lens 31, and a diffraction grating. 5 and an adhesive layer 6 for fixing the transparent body 71 and the diffraction grating 5 and the like.

The end surface 31b of the gradient index lens 31 is polished obliquely with respect to the optical axis. The radius of curvature of the convex spherical surface 31a of the gradient index lens 31 and the radius of curvature of the concave spherical surface 71a of the transparent body 71 are substantially equal. The end faces 20 of the input optical fiber 1 and the output optical fibers 21, 22, 23 are also obliquely polished and fixed to 31 on the gradient index lens. The refractive index lens 31 and the transparent body 71 are adjusted and fixed in a state where the convex spherical surface 31a and the concave spherical surface 71a are in close contact with each other. In particular, the gradient index lens 3 having the convex spherical surface 31a
Reference numeral 1 denotes an optical component that is easily available as a “front spherical gradient index lens” having a convex end surface in a process such as polishing. The concave spherical surface 71a of the transparent body 71 is formed according to the radius of curvature of the convex spherical surface 31a. By setting the curvatures to be equal, it is possible to realize a stable and compact optical multiplexer / demultiplexer that does not require the transparent body 82 as compared with the first embodiment and has a small number of components.

Next, FIG. 5 shows a method of manufacturing the optical multiplexer / demultiplexer according to the second embodiment. As shown in FIG.
An input optical fiber 1, an output optical fiber 21, 22, 23, a gradient index lens 31, which are formed in a predetermined shape in advance,
The diffraction grating 5 and the transparent body 71 are prepared. In particular, the transparent body 71 is formed by pressing an optical material such as glass by using a mold having an inverse shape. Next, as shown in (b), the diffraction grating 5 and the transparent body 71 are first bonded and fixed by the adhesive layer 6. Further, the input optical fiber 1 and the output optical fibers 21, 22, 23 are arranged on the end surface 31b side of the gradient index lens 31 and fixed. In this step, no particular strict optical axis adjustment is required except that the output optical fibers 21, 22, and 23 are linearly arranged and fixed together with the input optical fiber 1 near the optical axis of the gradient index lens 31.

Next, as shown in (c), a UV-curable resin having lubricity is applied between the concave spherical surface 71a of the transparent body 71 and the convex spherical surface 31a of the gradient index lens 31,
The optical axis is adjusted by abutting the transparent body 71 and the gradient index lens 31 against each other while applying a force to press them against each other. At this time, since the concave spherical surface 71a and the convex spherical surface 31a have substantially the same radius of curvature, the end surfaces thereof are in close contact with each other. Therefore, with respect to the diffraction grating 5, there are three wavelength dispersion directions (direction of arrow A in the figure), tilting directions (direction of arrow B in the figure), and rotation directions in the grating plane (direction of arrow C in the figure). Even when the axis is adjusted, the transparent body 71 and the gradient index lens 3 are always used.
1 is in a state of close contact. In this way, the signal lights of the wavelengths λ1, λ2, and λ3 from the input optical fiber 1 are wavelength-separated by the diffraction grating 5, and the output optical fiber 2
The optical axis is adjusted so as to be coupled to 1, 22, 23. After adjusting the optical axis, ultraviolet rays are irradiated to the contact portion between the concave spherical surface 71a and the convex spherical surface 31a to cure the ultraviolet curable resin, and the gradient index lens 31 and the transparent body 71 are bonded.

Next, another configuration example of the second embodiment is shown in FIG. Compared with the optical multiplexer / demultiplexer shown in FIG. 4, the optical multiplexer / demultiplexer shown in FIG. 6 has a gradient index lens 31 and a transparent body 7.
The difference is that the concavities and convexities of the surfaces 31a and 71a that are in close contact with each other are opposite. In this way, the surfaces 31a and 7 which are in close contact with each other are
It goes without saying that the same effect can be obtained by reversing the unevenness of 1a.

(Third Embodiment) Next, a third embodiment of the optical multiplexer / demultiplexer and the manufacturing method thereof according to the present invention will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 7 is a sectional view showing a configuration example of the third embodiment of the optical multiplexer / demultiplexer of the present invention, and FIG. 8 is a sectional view showing another configuration example of the third embodiment.

The optical multiplexer / demultiplexer shown in FIG. 7 has an input optical fiber 1 and, for example, three output optical fibers 21, 22, 23.
And a refractive index distribution lens 3 which plays a role of a collimating lens, and a transparent body 81 which is provided on one end 3a side of the refractive index distribution lens 3 and has one convex surface (a convex spherical surface) 81a. A diffractive element 50 having a concave substantially spherical surface (hereinafter, referred to as a concave spherical surface) 50a facing the convex spherical surface 81a at one end and a diffraction grating 51 and a reflective film 52 at the other end is configured.

Of the both end faces 3a, 3b of the gradient index lens 3, at least the input / output optical fibers 1, 12, 22, 2
The end surface 3b on the 3 side is polished obliquely with respect to the optical axis.
The radius of curvature of the convex spherical surface 81a of the transparent body 81 and the radius of curvature of the concave spherical surface 50a of the diffraction element 50 are substantially equal. The end faces 20 of the input optical fiber 1 and the output optical fibers 21, 22, 23 are also obliquely polished and fixed to 3 on the gradient index lens. The transparent body 81 is closely fixed to the one end 3a of the refractive index lens 3, and the transparent body 81 and the diffractive element 50 are adjusted and fixed so that the convex spherical surface 81a and the concave spherical surface 50a are in close contact with each other.

Next, a method of manufacturing the optical multiplexer / demultiplexer according to the third embodiment will be described (the drawing is omitted because it is clear from the first embodiment shown in FIG. 2). Similar to the first embodiment shown in FIG. 2, the input optical fiber 1 and the output optical fibers 21, 22 and 22, which have been molded into a predetermined shape in advance.
23, gradient index lens 3, diffractive element 50, and transparent body 8
Have 1 ready. In particular, the diffractive element 50 and the transparent body 81
It is preferable to mold an optical material such as glass by pressing using a mold having the opposite shape. next,
Input optical fiber 1 and output optical fibers 21, 22, 23
Is arranged on the end face 3b side of the gradient index lens 3 and fixed. In this step, no particular strict optical axis adjustment is required except that the output optical fibers 21, 22, 23 are linearly arranged and fixed together with the input optical fiber 1 near the optical axis of the gradient index lens 3.

Further, a force for pressing the diffractive element 50 and the transparent body 81 against each other in a state where a UV-curable resin having lubricity is applied between the concave spherical surface 50a of the diffractive element 50 and the convex spherical surface 81a of the transparent body 81. The optical axis is adjusted by abutting them while adding. At this time, the concave spherical surface 50a and the convex spherical surface 8
Since the radii of curvature of the substantially spherical shape of 1a are equal, the end faces of each la are in close contact with each other. Therefore, with respect to the diffraction grating 51, a wavelength dispersion direction (direction of arrow A in FIG. 7), a tilt direction (direction of arrow B in FIG. 7), and a rotation direction in the grating plane (direction of arrow C in FIG. 7). ) Even when adjusting the three axes, the diffraction element 5 is always
0 and the transparent body 81 are in close contact with each other. In this way, the signal axes of the wavelengths λ1, λ2, and λ3 from the input optical fiber 1 are wavelength-separated by the diffraction grating 51, and the optical axes are adjusted so as to be coupled to the output optical fibers 21, 22, and 23, respectively. After adjusting the optical axis, ultraviolet rays are applied to the contact portion between the concave spherical surface 50a and the convex spherical surface 81a to cure the ultraviolet curable resin and bond the diffractive element 50 and the transparent body 81.

Next, another configuration example of the third embodiment is shown in FIG. The optical multiplexer / demultiplexer shown in FIG. 8 is different from the optical multiplexer / demultiplexer shown in FIG. 7 in that the surfaces 50a and 81a of the diffractive element 50 and the transparent body 81, which are in close contact with each other, have opposite concavities and convexities. It goes without saying that similar effects can be obtained even if the concavities and convexities of the surfaces 50a and 81a that are in close contact with each other are reversed.

(Fourth Embodiment) Next, a fourth embodiment of the optical multiplexer / demultiplexer and the manufacturing method thereof according to the present invention will be described with reference to FIGS.
This will be described with reference to FIG. FIG. 9 is a sectional view showing a configuration example of the fourth embodiment of the optical multiplexer / demultiplexer of the present invention.
[Fig. 8] is a cross-sectional view showing another configuration example of the fourth embodiment.

The optical multiplexer / demultiplexer shown in FIG. 9 has an input optical fiber 1 and, for example, three output optical fibers 21, 22, 23.
And a substantially spherical surface with one convex surface (hereinafter referred to as a convex spherical surface) 31a
And the gradient index lens 31 serving as a collimating lens, and the convex spherical surface 31 of the gradient index lens 31 at one end.
Concave spherical surface (hereinafter referred to as concave spherical surface) 50 facing a.
It is composed of a diffractive element 50 having a and having a diffraction grating 51 and a reflective film 52 at the other end.

The end surface 31b of the gradient index lens 31 is polished obliquely with respect to the optical axis. Further, the convex spherical surface 31a of the gradient index lens 31 and the concave spherical surface 50a of the diffractive element 50 have substantially the same radius of curvature. The end faces 20 of the input optical fiber 1 and the output optical fibers 21, 22, 23 are also obliquely polished and fixed to 31 on the gradient index lens. The refractive index lens 31 and the diffractive element 50 are adjusted and fixed such that the convex spherical surface 31a and the concave spherical surface 50a are in close contact with each other.

Next, a method of manufacturing the optical multiplexer / demultiplexer according to the fourth embodiment will be described (the drawing is omitted because it is clear from the second embodiment shown in FIG. 5). Similar to the second embodiment shown in FIG. 5, the input optical fiber 1 and the output optical fibers 21, 22 and 22, which are molded in a predetermined shape in advance.
23, the gradient index lens 31, and the diffraction element 50 are prepared. In particular, it is preferable that the diffractive element 50 be formed by pressing an optical material such as glass by using a mold having an inverse shape. Next, the input optical fiber 1 and the output optical fibers 21, 22, 23 are arranged on the end face 31b side of the gradient index lens 31 and fixed. In this step, no particular strict optical axis adjustment is required except that the output optical fibers 21, 22, and 23 are linearly arranged and fixed together with the input optical fiber 1 near the optical axis of the gradient index lens 31.

Further, the diffractive element 50 and the gradient index lens 31 are mutually attached in a state in which a UV curable resin having lubricity is applied between the concave spherical surface 50a of the diffractive element 50 and the convex spherical surface 31a of the gradient index lens 31. The optical axis is adjusted by abutting the two while applying a pressing force. At this time, since the concave spherical surface 50a and the convex spherical surface 31a have substantially the same radius of curvature, the end surfaces thereof are in close contact with each other. Therefore, with respect to the diffraction grating 51, the wavelength dispersion direction (direction of arrow A in FIG. 9), the tilt direction (direction of arrow B in FIG. 9), and the rotation direction in the grating plane (direction of arrow C in FIG. 9). Even when the three axes are adjusted, the diffractive element 50 and the gradient index lens 31 are always in close contact with each other. In this way, the input optical fiber 1
The respective signal lights of wavelengths λ1, λ2, and λ3 from are separated into wavelengths by the diffraction grating 51, and output optical fibers 21 and 2, respectively.
The optical axis is adjusted so that the optical axis is coupled to the optical axes 2 and 23. After the optical axis adjustment, the contact portion between the concave spherical surface 50a and the convex spherical surface 31a is irradiated with ultraviolet rays to cure the ultraviolet curable resin, and the diffractive element 50 and the gradient index lens 31 are bonded. With such a configuration, the number of optical components other than the optical fibers 1, 21 to 23 can be reduced to a minimum of two. Further, since the diffractive element 50 is a component with little manufacturing variation, it is possible to obtain an optical multiplexer / demultiplexer with more stable characteristics.

Next, another configuration example of the fourth embodiment is shown in FIG. The optical multiplexer / demultiplexer shown in FIG. 10 is different from the optical multiplexer / demultiplexer shown in FIG. 9 in that the surfaces 50a and 31a of the diffractive element 50 and the gradient index lens 31, which are in close contact with each other, have opposite concavities and convexities. . In this way, the surfaces 50 that are in close contact with each other
It goes without saying that the same effect can be obtained even if the concavities and convexities of a and 31a are reversed.

(Fifth Embodiment) Next, a fifth embodiment of the optical multiplexer / demultiplexer of the present invention will be described with reference to FIG. FIG. 11 is a sectional view showing a configuration example of the fourth embodiment of the optical multiplexer / demultiplexer of the present invention. As shown in FIG. 11, the lens barrel 9 is provided outside the gradient index lens 3 and the first transparent body 81.
Is provided. Further, the cover 10 is provided so as to enclose the inner wall of the cover 10 without coming into contact with the first transparent body 72 and the diffraction grating 5. The cover 10 and the lens barrel 9 are fixed by a contact portion 11 and packaged. With such a configuration, the stress at the time of packaging is not directly applied to the diffraction grating 5 and its surrounding portion, which are the portions that most affect the characteristics, and the optical multiplexer / demultiplexer due to the deformation of the fixed portion caused by laser welding or the like. It is possible to reduce the influence on the optical characteristics of, and to make a stable module configuration.
The method of fixing each part is as follows: the cover 10 and the lens barrel 9
The most preferable method is laser welding, but fixing by soldering or adhesion is also possible.

In each of the above embodiments, the transparent body 71, 81, the gradient index lens 31,
Although the diffractive element 50 and the like are adhered, as a fixing method, the transparent bodies 71 and 81, the gradient index lens 31 and the diffractive element 50
It is also possible to use a method in which a side surface portion through which light does not pass is plated with metal, and laser welding or soldering is performed after adjusting the optical axis. With either method, the optical axis adjustment work can be performed smoothly, and since there is no optical axis deviation even when fixed, wavelength setting accuracy is high, transmission loss is small, and each optical component is in close contact with each other. It is possible to obtain a compact optical multiplexer / demultiplexer with stable characteristics by the integrated optical system.

Further, the refractive index distribution lenses 3 and 31 can be omitted by using a curved diffraction grating, a plane curved diffraction grating, a concave diffraction grating or the like instead of the flat diffraction gratings 5 and 51. In these cases, a lens for collimation is not required, the number of parts constituting the optical multiplexer / demultiplexer is reduced, the configuration is further simplified, and the entire optical multiplexer / demultiplexer can be downsized. Needless to say, a transparent adhesive having a matching refractive index is used for bonding the optical components. When a glass-based material is used, the reflectance can be set to -40 dB or less if the difference in the refractive index between adjacent portions is 0.03 or less in the relative refractive index difference.

Further, the diffraction gratings 5, 51 are provided near the centers of curvature of the transparent bodies 71 or the convex spherical surfaces 71a, 50a of the diffraction element 50.
By arranging the center of the diffraction grating, the incident light can be always incident on the effective central portions of the diffraction gratings 5 and 51 when the optical axis is adjusted. Therefore, it is possible to obtain the effect that the incident light does not deviate from the diffraction gratings 5 and 51 even if the optical axis is tilted by adjusting the optical axis.

[0048]

As described above, according to the first optical multiplexer / demultiplexer of the present invention, a plurality of optical fibers for inputting and outputting a wavelength-multiplexed optical signal and a plurality of optical signals having different wavelengths are transmitted by the optical fibers. Diffraction grating that separates the wavelength-multiplexed optical signal into optical signals of respective wavelengths or wavelength-multiplexes a plurality of optical signals, and a refractive index distribution lens that collimates the optical signals input and output by the optical fiber to the diffraction grating, A first transparent body provided on the grating surface of the diffraction grating and having a concave or concave substantially spherical surface on the side of the gradient index lens, and a first transparent body provided on the diffraction grating side of the gradient index lens. And a second transparent body having a convex or concave substantially spherical surface that comes into close contact with the concave or convex substantially spherical surface. Therefore, an optical axis adjustment mechanism is formed in the optical system between the optical fiber and the diffraction grating by a spherical bearing composed of a concave substantially spherical surface and a convex substantially spherical surface, so that the optical axis can be adjusted very easily. You can Further, when adjusting the optical axis, the concave or convex substantially spherical surfaces of the first and second transparent bodies are always in close contact with each other, so that the positional relationship of each optical component is stable, and each engineering component, especially the first and second The fixing of the second transparent body becomes easy. Further, during the fixing work, since each part is hard to move, the axis of the diffraction grating once adjusted does not shift, the wavelength setting accuracy becomes high, and the transmission loss becomes small.

The second optical multiplexer / demultiplexer of the present invention comprises a plurality of optical fibers for inputting / outputting a wavelength-multiplexed optical signal and a plurality of optical signals having different wavelengths, and a wavelength-multiplexed optical signal transmitted by the optical fiber. A diffraction grating for separating signals into optical signals of respective wavelengths or wavelength-multiplexing a plurality of optical signals, and a surface on the side of the diffraction grating is a convex or concave substantially spherical surface, and an optical signal input / output by an optical fiber is A refractive index distribution lens that collimates the diffraction grating, and a concave or convex shape provided on the grating surface of the diffraction grating and having a surface on the refractive index distribution lens side in close contact with the convex or concave substantially spherical surface of the refractive index distribution lens. And a transparent body that is a spherical surface. That is, the gradient index lens is the first
Since it also serves as the first transparent body in the optical multiplexer / demultiplexer, only one transparent body is required. In addition to the effect of the first optical multiplexer / demultiplexer,
This has the effect of reducing the number of parts.

In the third optical multiplexer / demultiplexer of the present invention, a plurality of optical fibers for inputting and outputting the wavelength division multiplexed optical signal and a plurality of optical signals having different wavelengths and a diffraction grating are formed on one end face. , The other end surface is a concave or convex substantially spherical surface, and a diffractive element for separating the wavelength-multiplexed optical signal transmitted by the optical fiber into optical signals of respective wavelengths or wavelength-multiplexing a plurality of optical signals, and an optical fiber A refractive index distribution lens that collimates an optical signal input and output by a diffractive element, and a convex or concave shape that is provided on the diffractive element side of the refractive index distribution lens and adheres to a concave or convex substantially spherical surface of the diffractive element. And a transparent body having a spherical surface. That is, since the second transparent body and the diffraction grating in the first optical multiplexer / demultiplexer are integrated, only one transparent body is required. In addition to the effect of the first optical multiplexer / demultiplexer, the number of parts is increased. Has the effect of being less.

Further, the fourth optical multiplexer / demultiplexer of the present invention has a plurality of optical fibers for inputting and outputting a wavelength division multiplexed optical signal and a plurality of optical signals having different wavelengths, and a diffraction grating formed on one end face thereof. A diffractive element for separating the wavelength-multiplexed optical signal transmitted by the optical fiber into optical signals of respective wavelengths or for wavelength-multiplexing a plurality of optical signals, the other end face being a concave or convex substantially spherical surface The end face on the side is a convex or concave substantially spherical surface that closely adheres to the concave or convex substantially spherical surface of the diffraction element,
A refractive index distribution lens for collimating an optical signal input / output by an optical fiber to a diffractive element. That is,
The gradient index lens is the first in the first optical multiplexer / demultiplexer.
The second transparent body and the diffraction grating are integrated, and the transparent body is unnecessary, and in addition to the effects of the first to third optical multiplexers / demultiplexers, the number of parts is further reduced. Has the effect.

Further, by providing a housing having an internal space capable of accommodating at least the diffraction grating and the transparent body or the diffraction element supporting the diffraction grating so as not to contact the inner wall of the diffraction grating, it is the portion that most affects the characteristics. Since stress during packaging is not directly applied to the diffraction grating and its surroundings, it is possible to reduce the influence on the optical characteristics of the optical multiplexer / demultiplexer due to the deformation of the fixed part caused by laser welding etc., and a stable module It can be configured.

On the other hand, in the first method of manufacturing an optical multiplexer / demultiplexer according to the present invention, a plurality of optical fibers for inputting and outputting a wavelength division multiplexed optical signal and a plurality of optical signals having different wavelengths are transmitted through the optical fibers. It is provided with a diffraction grating for separating a wavelength-multiplexed optical signal into optical signals of respective wavelengths or for wavelength-multiplexing a plurality of optical signals, and a refractive index distribution lens for collimating an optical signal input / output by an optical fiber to the diffraction grating. A method of manufacturing an optical multiplexer / demultiplexer, comprising: providing a first transparent body having a concave or convex substantially spherical surface on the grating surface of the diffraction grating on the grating surface of the diffraction grating; A second transparent body having a convex or concave substantially spherical surface that closely adheres to the concave or convex substantially spherical surface of the first transparent body is provided on the side, and ultraviolet curing is performed between the concave and convex substantially spherical surfaces. Adjust the optical axis with resin filled and in close contact with each other Conducted after optical axis adjustment ends, fixed by irradiating ultraviolet rays to the contact portion of the substantially spherical and convex substantially spherical concave. Therefore, except for arranging the optical fibers linearly and arranging and fixing them near the optical axis of the gradient index lens, no special strict optical axis adjustment is required. In addition, a UV-curable resin having lubricity is applied between the concave substantially spherical surface of the second transparent body and the convex substantially spherical surface of the first transparent body, and the second transparent body and the first transparent body
The optical axes can be adjusted very easily by abutting the two transparent bodies while applying a force to push them against each other. Further, when adjusting the optical axis, the concave or convex substantially spherical surfaces of the first and second transparent bodies are always in close contact with each other, so that the positional relationship of each optical component is stable, and each engineering component, especially the first and second The fixing of the second transparent body becomes easy. Further, during the fixing work, since the respective parts are difficult to move, the axis of the diffraction grating once adjusted does not shift, the wavelength setting accuracy of the obtained optical multiplexer / demultiplexer becomes high, and the transmission loss becomes small.

In the second method of manufacturing an optical multiplexer / demultiplexer of the present invention, a plurality of optical fibers for inputting and outputting a wavelength division multiplexed optical signal and a plurality of optical signals having different wavelengths are transmitted through the optical fibers. It is provided with a diffraction grating for separating a wavelength-multiplexed optical signal into optical signals of respective wavelengths or for wavelength-multiplexing a plurality of optical signals, and a refractive index distribution lens for collimating an optical signal input / output by an optical fiber to the diffraction grating. A method for manufacturing an optical multiplexer / demultiplexer, wherein the surface of the gradient index lens on the side of the diffraction grating is molded into a convex or concave substantially spherical surface, and the surface on the side of the gradient index lens has a refractive index on the grating surface of the diffraction grating. Provide a transparent body that is a concave or convex substantially spherical surface that closely adheres to the convex or concave substantially spherical surface of the distribution lens, fill the space between the concave substantially spherical surface and the convex substantially spherical surface with an ultraviolet curable resin, and adhere to each other. Adjust the optical axis in the state After the completion, ultraviolet is irradiated to the contact portion of the substantially spherical and convex substantially spherical concave fixing. That is, since the gradient index lens also serves as the first transparent body in the first optical multiplexer / demultiplexer, the step of joining the first transparent body and the gradient index lens is unnecessary, and the first optical multiplexer / demultiplexer is used. In addition to the effect of the manufacturing method of (1), it has an effect of reducing the number of parts joining steps.

In the third method of manufacturing an optical multiplexer / demultiplexer according to the present invention, a plurality of optical fibers for inputting and outputting a wavelength division multiplexed optical signal and a plurality of optical signals having different wavelengths are transmitted through the optical fibers. A diffractive element for separating a wavelength-multiplexed optical signal into optical signals of respective wavelengths or wavelength-multiplexing a plurality of optical signals, and a refractive index distribution lens for collimating an optical signal input / output by an optical fiber to the diffractive element A method of manufacturing an optical multiplexer / demultiplexer, wherein a diffraction grating is formed on one end face of a diffractive element, and the other end face forms a concave or convex substantially spherical surface, and the diffractive element is provided on the diffractive element side of the gradient index lens. Provide a transparent body having a convex or concave substantially spherical surface that closely adheres to the concave or convex substantially spherical surface, and fill the ultraviolet curable resin between the concave substantially spherical surface and the convex substantially spherical surface, and in a state of closely contacting each other. Adjust the optical axis and finish the optical axis adjustment. After, fixed by irradiating ultraviolet rays to the contact portion of the substantially spherical and convex substantially spherical concave. That is, since the second transparent body and the diffraction grating in the first optical multiplexer / demultiplexer are integrated, the step of joining the second transparent body and the diffraction grating is unnecessary, and the first optical multiplexer / demultiplexer is used. In addition to the effect of the manufacturing method of (1), it has an effect of reducing the number of parts joining steps.

In the fourth method of manufacturing an optical multiplexer / demultiplexer according to the present invention, a plurality of optical fibers for inputting and outputting a wavelength division multiplexed optical signal and a plurality of optical signals having different wavelengths are transmitted through the optical fibers. A diffractive element for separating a wavelength-multiplexed optical signal into optical signals of respective wavelengths or wavelength-multiplexing a plurality of optical signals, and a refractive index distribution lens for collimating an optical signal input / output by an optical fiber to the diffractive element A method of manufacturing an optical multiplexer / demultiplexer, in which a diffraction grating is formed on one end face of a diffraction element, the other end face forms a concave or convex substantially spherical surface, and the end face on the diffraction element side is a concave or Formed into a convex or concave substantially spherical surface that is in close contact with the convex substantially spherical surface, filling the ultraviolet curable resin between the concave substantially spherical surface and the convex substantially spherical surface, and adjusting the optical axis in a state of being in close contact with each other, After the optical axis adjustment,
Ultraviolet rays are radiated and fixed on the contact portion between the concave and convex spherical surfaces. That is, since the refractive index distribution lens also serves as the first transparent body in the first optical multiplexer / demultiplexer, and the second transparent body and the diffraction grating are integrated, the first transparent body and the refractive index distribution lens. It becomes unnecessary to perform the step of joining the two and the step of joining the second transparent body and the diffraction grating, and in addition to the effect of the manufacturing method of the first to third optical multiplexers / demultiplexers, the step of joining the parts is further reduced. Have an effect.

In the method of manufacturing each of the above optical multiplexers / demultiplexers,
By forming the (first and second) transparent body and the diffraction grating by press working with a mold having an opposite phase of the shape, the manufacturing process of each part can be simplified and the manufacturing cost can be reduced. .

[Brief description of drawings]

FIG. 1 is a sectional view showing a configuration example of a first embodiment of an optical multiplexer / demultiplexer of the present invention.

FIG. 2 is a process diagram showing a method for manufacturing the optical multiplexer / demultiplexer shown in FIG.

FIG. 3 is a cross-sectional view showing another configuration example of the optical multiplexer / demultiplexer according to the first embodiment.

FIG. 4 is a sectional view showing a configuration example of a second embodiment of the optical multiplexer / demultiplexer of the present invention.

5A to 5C are process diagrams showing a manufacturing method of the optical multiplexer / demultiplexer shown in FIG.

FIG. 6 is a cross-sectional view showing another configuration example of the optical multiplexer / demultiplexer according to the second embodiment.

FIG. 7 is a sectional view showing a configuration example of a third embodiment of the optical multiplexer / demultiplexer of the present invention.

FIG. 8 is a sectional view showing another configuration example of the optical multiplexer / demultiplexer according to the third embodiment.

FIG. 9 is a sectional view showing a configuration example of a fourth embodiment of the optical multiplexer / demultiplexer of the present invention.

FIG. 10 is a cross-sectional view showing another configuration example of the optical multiplexer / demultiplexer according to the fourth embodiment.

FIG. 11 is a sectional view showing a configuration example of a fifth embodiment of the optical multiplexer / demultiplexer of the present invention.

FIG. 12 is a sectional view showing a configuration of a conventional optical multiplexer / demultiplexer.

[Explanation of symbols]

 1: Input optical fiber 3: Refractive index distribution lens 4: Adhesive layer 5: Diffraction grating 6: Adhesive layer 9: Lens barrel 10: Cover 11: Contact part 21: Output optical fiber 22: Output optical fiber 23: Output optical fiber 31 : Refractive index distribution lens 31a: Convex or concave substantially spherical surface 50: Diffraction element 71: First transparent body 71a: Convex or concave substantially spherical surface 81: Second transparent body 81a: Convex or concave substantially spherical surface

Claims (16)

[Claims] 1. A plurality of optical fibers for inputting and outputting a wavelength-multiplexed optical signal and a plurality of optical signals having different wavelengths, and a wavelength-multiplexed optical signal transmitted by the optical fiber is separated into optical signals of respective wavelengths. Alternatively, a diffraction grating that wavelength-multiplexes a plurality of optical signals, a refractive index distribution lens that collimates the optical signals input and output by the optical fiber to the diffraction grating, and the refractive index provided on the grating surface of the diffraction grating A first transparent body having a concave or concave substantially spherical surface on the side of the distribution lens; and a concave or convex substantially spherical surface of the first transparent body provided on the diffraction grating side of the gradient index lens. An optical multiplexer / demultiplexer comprising a second transparent body having a convex or concave substantially spherical surface that is in close contact with the second transparent body. 2. A plurality of optical fibers for inputting and outputting a wavelength multiplexed optical signal and a plurality of optical signals having different wavelengths, and a wavelength multiplexed optical signal transmitted by the optical fiber is separated into optical signals of respective wavelengths. Or, a diffraction grating for wavelength-multiplexing a plurality of optical signals, the surface on the diffraction grating side is a convex or concave substantially spherical surface, and a refractive index distribution for collimating the optical signal input / output by the optical fiber to the diffraction grating. A lens and a transparent surface provided on the grating surface of the diffraction grating, the surface on the side of the gradient index lens being a concave or convex substantially spherical surface that is in close contact with the convex or concave substantially spherical surface of the gradient index lens. An optical multiplexer / demultiplexer having a body. 3. A plurality of optical fibers for inputting / outputting a wavelength-multiplexed optical signal and a plurality of optical signals having different wavelengths, and a diffraction grating formed on one end face, and the other end face being a concave or convex substantially spherical surface. A diffractive element that separates the wavelength-multiplexed optical signal transmitted by the optical fiber into optical signals of respective wavelengths or wavelength-multiplexes a plurality of optical signals; and A refractive index distribution lens that collimates the element, and a transparent body that is provided on the diffraction element side of the refractive index distribution lens and has a convex or concave substantially spherical surface that is in close contact with the concave or convex substantially spherical surface of the diffraction element. And an optical multiplexer / demultiplexer. 4. A plurality of optical fibers for inputting / outputting a wavelength-multiplexed optical signal and a plurality of optical signals having different wavelengths, and a diffraction grating formed on one end face, and the other end face being a concave or convex substantially spherical surface. And a diffractive element that separates the wavelength-multiplexed optical signal transmitted by the optical fiber into optical signals of respective wavelengths or wavelength-multiplexes a plurality of optical signals, and the end face on the side of the diffractive element is the concave shape of the diffractive element. Alternatively, an optical multiplexer / demultiplexer having a convex or concave substantially spherical surface that is in close contact with the convex substantially spherical surface, and including a gradient index lens that collimates the optical signal input and output by the optical fiber to the diffraction element. 5. The optical multiplexer / demultiplexer according to claim 1, wherein the concave substantially spherical surface and the convex substantially spherical surface have the same radius of curvature. 6. The optical coupling / decoupling device according to claim 1, wherein the optical fiber end surface and the end surface of the gradient index lens contacting the optical fiber end surface are polished or cut obliquely with respect to the optical axis. Wave instrument. 7. The optical multiplexer / demultiplexer according to claim 1, further comprising a housing having an internal space capable of accommodating at least the diffraction grating and the second transparent body so as not to contact an inner wall thereof. 8. The optical multiplexer / demultiplexer according to claim 2, further comprising a housing having an internal space capable of accommodating at least the diffraction grating and the transparent body so as not to contact an inner wall thereof. 9. The optical multiplexer / demultiplexer according to claim 3, further comprising a housing having an internal space capable of accommodating at least the diffraction element so as not to contact the inner wall thereof. 10. A plurality of optical fibers for inputting / outputting a wavelength-multiplexed optical signal and a plurality of optical signals having different wavelengths, and a wavelength-multiplexed optical signal transmitted by the optical fiber is separated into optical signals of respective wavelengths. Alternatively, there is provided a method of manufacturing an optical multiplexer / demultiplexer, comprising: a diffraction grating that wavelength-multiplexes a plurality of optical signals; and a refractive index distribution lens that collimates the optical signals input and output by the optical fiber to the diffraction grating, A first transparent body having a concave or convex substantially spherical surface on the side of the gradient index lens is provided on the grating surface of the diffraction grating, and the first transparent body is provided on the diffraction grating side of the gradient index lens. Provide a second transparent body having a convex or concave substantially spherical surface that closely adheres to the concave or convex substantially spherical surface, and fill an ultraviolet curable resin between the concave substantially spherical surface and the convex substantially spherical surface, Optical axis adjustment in close contact with each other Conducted after optical axis adjustment ends, the method for manufacturing an optical demultiplexer for fixing the UV is irradiated to the contact portion of the substantially spherical and convex substantially spherical surface of the concave. 11. A plurality of optical fibers for inputting and outputting a WDM optical signal and a plurality of optical signals having different wavelengths, and a WDM optical signal transmitted by the optical fiber is separated into optical signals of respective wavelengths. Alternatively, there is provided a method of manufacturing an optical multiplexer / demultiplexer, comprising: a diffraction grating that wavelength-multiplexes a plurality of optical signals; and a refractive index distribution lens that collimates the optical signals input and output by the optical fiber to the diffraction grating, The surface of the refractive index distribution lens on the side of the diffraction grating is molded into a convex or concave substantially spherical surface, and the surface on the side of the refractive index distribution lens on the grating surface of the diffraction grating is the convex or the surface of the refractive index distribution lens. Provide a transparent body that is a concave or convex substantially spherical surface that is in close contact with the concave substantially spherical surface, fill the space between the concave substantially spherical surface and the convex substantially spherical surface with an ultraviolet curable resin, and keep the optical axis in close contact with each other. Adjust the optical axis Sei After completion, the method for manufacturing an optical demultiplexer for fixing the UV is irradiated to the contact portion of the substantially spherical and convex substantially spherical surface of the concave. 12. A plurality of optical fibers for inputting and outputting a WDM optical signal and a plurality of optical signals having different wavelengths, and a WDM optical signal transmitted by the optical fiber is separated into optical signals of respective wavelengths. Alternatively, a method of manufacturing an optical multiplexer / demultiplexer comprising a diffractive element that wavelength-multiplexes a plurality of optical signals, and a refractive index distribution lens that collimates an optical signal input and output by the optical fiber to the diffractive element, A diffraction grating is formed on one end surface of the diffractive element, and the other end surface forms a concave or convex substantially spherical surface, and the concave or convex substantially concave surface of the diffractive element is provided on the diffractive element side of the gradient index lens. Provide a transparent body having a convex or concave substantially spherical surface that adheres closely to the spherical surface, fill the UV curable resin between the concave substantially spherical surface and the convex substantially spherical surface, and adjust the optical axis in a state of being in close contact with each other. , Optical axis adjustment end After, a method of manufacturing an optical demultiplexer for fixing the UV is irradiated to the contact portion of the substantially spherical and convex substantially spherical surface of the concave. 13. A plurality of optical fibers for inputting and outputting a WDM optical signal and a plurality of optical signals having different wavelengths, and a WDM optical signal transmitted by the optical fiber is separated into optical signals of respective wavelengths. Alternatively, a method of manufacturing an optical multiplexer / demultiplexer comprising a diffractive element that wavelength-multiplexes a plurality of optical signals, and a refractive index distribution lens that collimates an optical signal input and output by the optical fiber to the diffractive element, A diffraction grating is formed on one end surface of the diffractive element, and the other end surface forms a concave or convex substantially spherical surface, and the end surface on the side of the diffractive element is brought into close contact with the concave or convex substantially spherical surface of the diffractive element. Formed into a convex or concave substantially spherical surface, filling an ultraviolet curing resin between the concave substantially spherical surface and the convex substantially spherical surface,
A method of manufacturing an optical multiplexer / demultiplexer in which optical axes are adjusted in a state of being in close contact with each other, and after the optical axis adjustment is completed, ultraviolet rays are applied to and fixed to the contact portions of the concave substantially spherical surface and the convex substantially spherical surface. 14. The method of manufacturing an optical multiplexer / demultiplexer according to claim 10, wherein the first and second transparent bodies are formed by press working with a mold having a phase opposite to that of the first and second transparent bodies. 15. The method of manufacturing an optical multiplexer / demultiplexer according to claim 11, wherein the transparent body is formed by press working with a die having a phase opposite to that of the transparent body. 16. The diffractive element is formed by pressing with a mold having an opposite phase of its shape.
Or the manufacturing method of the optical multiplexer / demultiplexer according to 13.