JPH01136106A - Organic light guide - Google Patents

Abstract

PURPOSE:To decrease a light propagation loss by applying a compsn. consisting of a specific compd. and photoinitiator on a base, then forming a light guide by a photolithographic method. CONSTITUTION:The compsn. contg. the bromine compd. expressed by formula I, the polystyrene compd. contg. the repeating unit expressed by formula II and the photoinitiator is formed to a film shape on a base having the refractive index lower than the refractive index of the polymer of said compsn. and thereafter, the light guide is formed by the photolithographic method. In formula I, X denotes CH2, C(CH3)2, CH=CH, O or SO2; R denotes CH3 or H; R1 denotes COCH=CH2, COC(CH3)=CH2 or H: R2 denotes COCH=CH2 or COC(CH3)=CH2; n+m denotes integer in the range of 0-4. In formula II, Y denotes H, CH3, CH=CH2, OCH3 or Cl. The small light propagation loss and the high refractive index are thereby obtd. and the light loss in an optical branching/coupling part is decreased.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to an organic guided waveguide using photoresist as an optical transmission path.As an application field of the 0-wire organic optical waveguide, it is applicable to optical components for optical communication. Yes, it is commonly used in optical branching couplers, star couplers, optical accessors, etc.

[Conventional technology and its problems]

Various materials have been proposed for organic guiding waveguides using photoresists, but they suffer from large phototransmission and loss.
It has been difficult to be used in optical branching and coupling devices due to problems such as a low refractive index, a narrow range of support selections, insufficient lithography properties, and large optical loss at the optical branching and coupling portion.

[Means for solving problems]

The present invention was made as a result of intensive research to overcome the above problems, and its purpose is to reduce optical propagation loss, have a high refractive index, and reduce optical loss at the optical branching/coupling section. The objective is to provide a small organic guiding waveguide.

The present invention provides a bromine compound represented by the following general formula (A), in which X is C4, C(CH,), CH-CH, C1 or), and a compound represented by the following general formula (B). A composition containing a polystyrene compound containing a repeating unit and a photoinitiator is formed into a film on a support having a refractive index lower than that of a polymer of the composition, and then shaped by a photolithography method. This relates to an organic guiding waveguide characterized by:

In the brominated compound represented by the above general formula (A) in the present invention, at least one of 8 and 8 is an acroyl group or a methacryloyl group, and such a reactive group participates in polymerization. Moreover, n+m is in the range of 0 to 4, preferably in the range of 2 to 4.

To explain the bromide of the present invention by giving specific examples, the following bromides (1) to (9) may be mentioned.The bromide of the present invention can be used as a single compound, but if necessary, It is also possible to use a mixture of a plurality of brominated compounds represented by the general formula (A>).

In the polystyrene compound containing the repeating unit represented by the general formula (B) in the present invention, Y is H, CH3, C
Hco CHL10C Aki, or CX.

Y is CH-CH! In the case of , such reactive groups participate in the polymerization. Y may be bonded to any position on the aromatic ring,
It is not particularly limited.

The polystyrene compound in the present invention has the general formula (B)
Although it is possible to use a single repeating unit represented by formula (B), it is also possible to use a repeating unit composed of multiple types of repeating units represented by general formula (B).

Furthermore, as a repeating unit of the polystyrene compound of the present invention, a copolymer into which a vinyl monomer such as butadiene or acrylonitrile is partially introduced can be used, if necessary.

The polystyrene compound of the present invention will be explained by giving specific examples. Multi-substituted styrene copolymers, such as divinylbenzene linear copolymers, styrene-p-methylstyrene copolymers, and p-chlorostyrene-p-methoxystyrene copolymers, styrene-
Examples include styrenic copolymers such as butadiene copolymers and styrene-acrylonitrile copolymers.

The molecular weight of the polystyrene compound of the present invention is not particularly limited, but is preferably from 1,000 to 1,000,000.

In the composition of the present invention, there are many possible combinations of the bromide and the polystyrene compound, but there are naturally appropriate combinations based on compatibility and the like. Especially the general formula (
A composition consisting of a combination of a bromide and polystyrene represented by C) has excellent compatibility, processability, polymerizability, and optical properties.

In the composition of the present invention, the optimum composition ratio of the bromide and the polystyrene compound is naturally determined depending on their physical properties and usage form, but the preferred composition ratio is:
Boristyrene compound-10 to 90: 90 to 10, more preferably 30 to 70: 70 to
The range is 30.

It is preferable that the photoinitiator in the present invention is substantially transparent to the light propagating through the organic guiding waveguide.Visible light or near-infrared light is often used as the light to propagate, and the photoinitiator As such, those that absorb or are sensitive to ultraviolet light or near ultraviolet light are allowed to pass through. Such photoinitiators include:
For example, benzoin methyl ether, benzoin isobutyl ether, dimethoxyphenylacetophenone, benzophenone, Michler's ketone, methylthioxanthone, 1-phenyl-1,2-propanedione-2-.

Examples include, but are not limited to, -(ethoxycarbonyl)oxime, and the most preferred light source for the photolithographic method using such a photoinitiator is a mercury lamp.

The appropriate content of the photoinitiator in the composition of the present invention depends on the absorption coefficient of the photoinitiator, polymerization efficiency, thickness of the organic guiding waveguide, etc., but is preferably in the range of 0.1 to 10% by weight, and A range of 1 to 5% by weight is preferred.

The composition of the present invention comprises a bromide of general formula (A), a bromide of general formula (A),
Although the polystyrene compound and photoinitiator of B) are the main components, it is preferable to add various additives as necessary. Examples of additives include, but are not limited to, sensitizers, stabilizers, thermal polymerization initiators, plasticizers, and colorants.

In the present invention, a composition consisting of the compounds of general formulas (A) and (B) and a photoinitiator is coated on a support having a refractive index lower than that of a polymerized product of the composition, and then formed by a photolithographic method. The present invention relates to an organic optical waveguide.

The support used in the present invention may be any material as long as it has a refractive index lower than that of the polymer of the composition.Since the refractive index of the polymer is approximately in the range of 1.57 to 1.63, approximately 1. 5
It is fine if it is 7 or less. If the support bed has absorption at the wavelength of the light propagating through the organic guide waveguide, the light propagation loss will increase, so it is preferable that the support bed be as transparent as possible. Polymer materials such as terephthalate, polyvinyl chloride, polyethylene, poly7crylonitrile, polyvinyl alcohol, polymethyl methacrylate, polyoxymethylene, polypropylene, polymethylpentene, silicone resin, polyvinylidene fluoride, polytetrafluoroethylene, etc.
Glass materials such as soda glass, Pyrex glass, Vycor glass, quartz glass, quartz, ADP, RDP
There are other single crystal materials such as It is also possible to treat the surface of the support for the purpose of improving adhesion to the organic guiding waveguide. Examples of such treatments include corona discharge treatment of the above-mentioned polymeric material and silane coupling treatment of the above-mentioned glass material.

The shape of the support used in the present invention is not particularly limited, and various shapes can be used. The thickness of the support is preferably approximately 10I! - or above is sufficient, and it is also possible to laminate with other materials for the purpose of maintaining the shape of the support.

In the present invention, the method of applying the composition to the support is not particularly limited, and commonly used coating methods can be applied. Examples of such coating methods include a spin code method, a bar code method, a roll coat method, a dipping method, and the like.

The present invention relates to an organic guiding waveguide formed from the composition by photolithography.

The photolithography method in the present invention refers to exposing a composition on a support to light such as ultraviolet rays through a photomask having a desired shape pattern, or exposing the composition to light such as an electron beam in a desired pattern. After exposing the exposed area to light, the unexposed area is washed away using the difference in solubility in a developing solution between the exposed area and the unexposed area, and a guiding waveguide having a desired shape pattern is obtained. In order to reduce oxygen that inhibits the polymerization of the composition, it is also possible to adopt methods such as carrying out the reaction in an inert atmosphere or adhering a sheet with low oxygen permeability to the composition.

The above-mentioned developer is not particularly limited as long as the solubility of the composition in the exposed area to the polymer is lower than the solubility in the unexposed area of the composition. Although the type of developer used naturally depends on the composition of the composition, organic developers are generally suitable for this purpose. Examples of preferred developers include methyl ethyl ketone, 1.1.
Examples include 1-trichloroethane, toluene, and tetrahydrofuran.

The present invention relates to an organic guide waveguide formed by photolithography.

In the organic optical waveguide of the present invention, the polymer of the composition in the exposed area is used as the core part, and the support is used as the cladding part. It is also possible to form a landing portion by coating the organic guiding waveguide on the support with a material having a lower refractive index than the organic guiding waveguide by coating or the like.

Although the shape of the organic guide waveguide in the present invention is not particularly limited, there is an optimum thickness depending on the mode of light to be propagated. In the case of single mode, the thickness is approximately 1 to 10 μm, and in the case of multimode, it is approximately 2
It is 0 to 1.000 p■.

Further, an organic guiding waveguide having an arbitrary shape can be formed depending on the pattern shape of the photomask and the shape of the irradiation beam.

Examples of shapes include straight lines, curves, Y-branches, multi-branches, 8-shapes, and the like.

〔Example〕

Next, examples will be shown.

Example 1 To a solution of 70 parts by weight of bromide (1), 30 parts of polystyrene, and 100 parts of methyl ethyl ketone, 2 parts of dimethoxyphenylacetophenone as a photoinitiator was added and mixed well. The above solution was barcoded onto a PMl'lA plate with a thickness of 1-1, and then dried by heating at 70°C to obtain a coating film with a thickness of about 100 μm. UV rays of 300a+J/c11 were irradiated from a high-pressure mercury lamp through a polyethylene terephthalate mask with a linear pattern, and the temperature was 300℃ at 70℃.
After heating for 0 minutes, it was developed with methyl ethyl ketone to obtain a leading waveguide having a thickness of 100 μm, a width of 100 μm, and a length of 10 cm. A He-Ne laser beam is input from the end face of the leading waveguide, and the light is rotated &! When I measured the loss, it was 0.2 dB/
It showed a good value of ca+.

Example 2 To a solution of 50 parts of bromide (2), 50 parts of polystyrene, and 110 parts of O-xylene, 2 parts of dimethoxyphenylacetophenone was added as a photoinitiator and mixed well.

The above solution was spin-coded onto a silane coupling-treated glass plate having a thickness of 11III at a rotational speed of 1500 rpm, and then dried by heating at 70° C. to obtain a coating film with a thickness of about 50 μm. After irradiating ultraviolet rays of 600 mJ/aJ from a high-pressure mercury lamp in a nitrogen atmosphere through a Cr quartz mask having a Y-branch pattern and heating at 70° C. for 10 minutes, 1.1.
1-) Developed with dichloroethane to obtain an optical waveguide having a thickness of 50μ, a line width of 50μ, a length of 5C, and a branching angle of 2θ-2°. Semiconductor laser light with a wavelength of 0.85 .mu.- was input from the end face of the optical waveguide and the amount of light from the output end was measured, and the branching loss was 3 dB.

Example 3 30 parts of bromide +9), poly(p-methylstyrene)
To a solution of 70 parts of dimethylformamide, 250 parts of dimethylformamide, and 250 parts of 0-xylene, 2 parts of benzoin methyl ether as a photoinitiator was added and mixed well. After applying thermosetting fluorine-containing resin to a thickness of 50 μm, it was heated and cured to a thickness of 1.
The above solution was barcoded onto a polyethylene terephthalate film of 00 μUo, and then dried by heating at 70° C. to obtain a coating film with a thickness of about 50 pH. PET with linear pattern
Ultraviolet rays from a high-pressure mercury lamp are transmitted through a mask made of
After being irradiated with 0O/- and heated at 70°C for 15 minutes, it was developed with methyl ethyl ketone to give a thickness of 50 μm and a width of 100 μ-
1 A leading wavepath of length 10c+w was obtained. When a He-Ne laser beam was incident on the end face of the optical waveguide and the optical propagation loss was measured, it was found to be 0.5 dB/am.

Examples 4 to 9 The same method as in Example 1 was carried out, except that the bromide (1) and polystyrene of Example 1 were changed to the compositions shown in Table 1, and the ultraviolet rays were irradiated with the amount of light shown in Table 1. A leading wavepath was created. Table 1 shows the optical propagation loss due to the He-Ne laser beam.

Table 1 Patent applicant: Asahi Kasei Industries, Ltd. Representative Patent Attorney Toru Hoshino

Claims (2)

[Claims] (1) A bromine compound represented by the general formula (A) below, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (A) [In the formula, X is CH_2, C(CH_3)_2, CH=CH
, O, or SO_2; R is CH_3 or H; R_1 is C
OCH=CH_2COC(CH_3)=CH_2 or H
;R_2 is COCH=CH_2 or COC(CH_3)
=CH_2; n+m represents an integer of 0 to 4. ] And the repeating unit represented by the following general formula (B) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (B) [In the formula, Y is H, CH_3, CH=CH_2, OCH_
3 or Cl. ] A composition containing a polystyrene compound and a photoinitiator is formed into a film on a support having a refractive index lower than that of a polymer of the composition, and then shaped by a photolithography method. organic optical waveguide. (2) Brominated compound is a compound represented by the general formula (C) below, and there are ▲mathematical formulas, chemical formulas, tables, etc.▼(C) [In the formula, R' is COCH=CH_2 or ▲mathematical formulas, chemical formulas,
There are tables etc. Represents ▼. ] The organic optical waveguide according to claim 1, wherein the polystyrene compound is polystyrene.