JPS61172106A - Production of optical waveguide - Google Patents

Abstract

PURPOSE:To form an optical waveguide with a less joint loss to an optical fiber by pattern-exposing and sensitizing a photosensitive resin so as to form a curing agent which has a rectangular sectional shape and becomes the core of the core layer of the optical waveguide, coating a homogeneous photosensitive resin and executing exposing and sensitizing steps with respect to all sides. CONSTITUTION:A transparent film 7 is put on a glass substrate 6, and thereon a spacer 8 is placed and filled with the photosensitive resin 9, on which a transparent film 10 is put as a cover to interrupt air. On the film 10 a mask 11 is placed in a desired shape, and the pattern exposure is executed by an incident light beam 12. No-exposed part is removed by etching. The sectional shape of the curing agent 5 for becoming the core of the core layer obtained in such a way is rectangular. The homogeneous photosensitive resin is dropped and coated on a side surface 5a in the axial direction of the curing agent 5, exposed in this state and cured, thereby obtaining the peripheral part 13 of the core layer. Said steps are applied to other three sides 5b, 5c and 5d to form the peripheral parts 14, 15 and 16 of the core layer.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for manufacturing an optical waveguide using a photosensitive resin.

[Background technology]

Conventionally, when producing an optical waveguide using a photosensitive resin, one as shown in FIG. 1 has been produced.

First, a substrate 1 is coated with a cuturad layer 2, a resin (core layer) 3 exposed to light with a mask pattern of a desired shape is placed on top of the substrate 1, and the surface thereof is further covered with layers of cladding and cladding to form an optical waveguide. It is made into a block by embedding it with embedding resin 4 or the like. The core layer 3 was conventionally formed by exposing it to light as shown in Fig. 2 and then processing and cleaning it, so the cross section perpendicular to the optical axis of the optical waveguide had a rectangular shape. was. When creating an optical waveguide using the optical waveguide created in this way and considering connecting it to an optical fiber,
Disadvantages include an increase in connection loss due to differences in cross-sectional shapes and a reduction in the transmission distance of the optical fiber.

[Purpose of the invention]

The present invention has been made to improve the above points, and its purpose is to provide a method for manufacturing an optical waveguide with less coupling loss with an optical fiber caused by differences in cross-sectional shape. It is in.

[Disclosure of the invention]

The present invention will be explained below based on the drawings shown as examples. First, as shown in FIG. 2, a cured product 6 that is to become the nucleus of the core layer is prepared. Transparent film 7 on glass substrate 6
, and place spacer 8 (hollow frame) on top of the film 7.
and fill it with photosensitive resin 9. A transparent film IO is placed on the photosensitive resin 9 as a cover,
Cut the air quickly. A mask U having a desired shape is placed on the film 1G, and pattern exposure is performed using irradiation light 4. The unexposed areas are removed by etching (cleaning). The cross-sectional shape of the cured product 5, which is to become the nucleus of the core layer obtained by V-filtering, is rectangular, and the pattern width of the mask U and the spacer 8
It changes depending on the thickness tK and the exposure conditions. Therefore, the width of the above pattern.

By selecting the thickness and exposure conditions, the cross-sectional shape can be changed from rectangular to square. Further, the size of the square is a square inscribed in the circular cross section of the core of the optical fiber to be used and connected.

Next, as shown in FIG. 3, a photosensitive resin of the same quality as the cured product 5 is dropped and coated on the axial side surface 5a of the cured product 5, which is to become the core of the core layer. Due to surface tension, the resin fills the gap between the side surface 5a of the cured product 5 and the circle 5' circumscribing the cured product 5.

The resin is exposed to light during this downward motion to harden it, forming a peripheral portion of the core layer. The above process is also performed for the other three sides 5b, 5c, 5d, and the peripheral parts 14, 15, 16 of the core layer are
form.

In this manner, a core layer 17 having a substantially circular cross-sectional shape is obtained. The circular core layer 17 is formed into blocks by conventional paper cutting and Cuturad layer formation, whereby an optical waveguide with less coupling loss due to the difference in cross-sectional shape with the optical fiber can be obtained.

The viscosity of the resin is adjusted by changing the formulation of the material itself and the salinity of the exposure atmosphere so that the cross-sectional shape of the core layer υ approaches a circle as much as possible.

〔Effect of the invention〕

As described above, according to the present invention, in the method for manufacturing a light traveling waveguide using a photosensitive resin, the photosensitive resin is subjected to pattern exposure,
When exposed to light, a cured product having a rectangular cross-sectional shape and serving as the core of the core layer of the optical waveguide is formed, and a photosensitive resin of the same quality as the photosensitive resin is applied to the axial side surface of the cured product. By exposing and sensitizing the above-mentioned process to all sides in the length direction of the cured product, an optical waveguide with a substantially circular cross-sectional shape can be obtained. We were able to provide a method for fabricating a leading waveguide with low coupling loss.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a conventional optical waveguide, FIG. 2 is a cross-sectional view showing a method for producing a cured material that is the core of the core layer of an optical waveguide according to an embodiment of the present invention, and FIG. 3 is a perspective view of a conventional optical waveguide. FIG. 3 is a cross-sectional view showing a method for manufacturing a peripheral portion of a core layer according to an example. 5... Cured product, 9... Fan-lighting resin, 13, 14
, 15, 16...periphery of the core layer.

Claims (1)

[Claims] (1) In a method for producing an optical waveguide using a photosensitive resin, the photosensitive resin is pattern-exposed and exposed to light to form a cured product having a rectangular cross-sectional shape and serving as the core of the core layer of the optical waveguide;
A photosensitive resin of the same quality as the above photosensitive resin is applied to the axial side surface of the cured product, exposed and exposed, and the above process is carried out on all sides of the cured product in the length direction, so that the cross-sectional shape becomes approximately circular. 1. A method for manufacturing an optical waveguide, characterized in that: