JP2004212775A - High polymer optical waveguide element and manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical waveguide element that enables an optical waveguide to be joined to an optical component to be connected such as an optical fiber without aligning, so that the connection is made possible with low loss, and to provide the manufacturing method of the element. <P>SOLUTION: The manufacturing method of the high polymer optical waveguide element is characterized in that a laser beam having a wavelength λ1 is made incident to a solution in which a photosensitizer for absorbing and decomposing light having the wavelength λ1 is mixed in a photosetting resin, thereby hardening the optical path of the laser beam to form the core, and then the entirety is hardened by irradiating it with photosetting light to form a clad. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a polymer optical waveguide, and more particularly to a method for manufacturing an optical waveguide such as an optical integrated circuit, an optical interconnection, or an optical component, which is inexpensive and has low connection loss.
[0002]
[Prior art]
In recent years, when connecting an optical fiber to an optical waveguide or when connecting a laser diode to an optical fiber or an optical waveguide, laser welding, fixing with an adhesive, mode field matching using a lens system, and the like have been performed. When the optical fiber or the optical waveguide is made of a polymer, laser welding or the like cannot be used. Therefore, the optical fiber or the optical waveguide is mainly fixed using an ultraviolet-curable adhesive. In this case, alignment takes a long time in mounting the optical fiber and the optical waveguide, and a connection loss becomes large due to a cause of axis deviation or the like. In the case of a laser diode, an optical fiber, and an optical waveguide, a lens system is used, so that the cost is extremely high. There is a method in which a spot size conversion function is provided to the optical waveguide portion in the laser diode to perform mode field matching, but the laser diode itself becomes very expensive. For this reason, an optical waveguide that can be connected to an optical component without any adjustment is desired.
[0003]
A self-formed optical waveguide using two resins having different refractive indexes has been proposed (Patent Document 1: Japanese Patent Application Laid-Open No. H11-326660). A method has been reported in which a resin having a high refractive index is hardened more by applying argon laser light or UV to form a core. However, in this case, the materials of the core and the clad are limited, and the optical waveguide can be formed only by a specific laser beam. The ability to form an optical waveguide with an arbitrary laser beam enables light to be transmitted as it is with the light formed by the optical waveguide. It is possible to achieve the difficult alignment without centering, and to develop a wide range of other applications. However, a method for achieving this has not yet been proposed.
[0004]
[Patent Document 1] Japanese Patent Application Laid-Open No. H11-326660
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION An object of the present invention is to provide an optical waveguide device and a method for manufacturing the same, in which a connected optical component such as an optical fiber and an optical waveguide are joined without any alignment, thereby enabling low-loss connection.
[0006]
[Means for Solving the Problems]
The present inventor has conducted extensive studies, and as a result, irradiates a laser light into a solution obtained by mixing a photosensitizer in a photocurable resin, and forms the core and the clad while suppressing the spread of the solution propagation light. The present invention was found to be solved, and the present invention was completed.
[0007]
That is, the present invention relates to a method in which a laser beam having a wavelength of λ1 is incident on a solution in which a photosensitizer that absorbs and decomposes light having a wavelength of λ1 is mixed in a photocurable resin, thereby curing an optical path of the laser beam. And then irradiating the entire surface with light for photocuring and curing to form a clad, thereby forming a polymer optical waveguide device.
[0008]
Further, the present invention relates to an optical waveguide device having a polymer core and a clad, wherein the concentration in the clad of the photosensitizer that absorbs and decomposes the laser light of wavelength λ1 is higher than the concentration in the core. A polymer optical waveguide device characterized in that:
[0009]
In the present invention, it is preferable that the absorption peak wavelength of the photosensitizer is on the longer wavelength side than the light wavelength λ2 to be propagated by the optical waveguide device. Further, the photosensitizer is preferably a dye. As a result, the difference in the refractive index between the core portion after the photosensitizer has been decomposed and the clad that has not been decomposed is sufficient for confining light.
[0010]
Here, the polymer optical waveguide element may be one in which a light receiving element, a light emitting element, an optical fiber, or an optical waveguide is joined to the polymer optical waveguide.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described in detail. Examples of the photocurable resin include various materials such as a UV curable resin and a visible light curable resin, and epoxy, acrylic, and urethane. As the photosensitizer, various materials such as a dye and a visible light polymerization initiator can be considered.
[0012]
The maximum value and the minimum value of the refractive index dispersion curve change depending on the content of the photosensitizer used here. The dispersion curve of the refractive index of the photosensitizer is shown in FIG. It can be seen that the refractive index decreases as the amount of the photosensitizer increases on the shorter wavelength side of the absorption peak of the photosensitizer, and increases as the amount of the photosensitizer increases on the longer wavelength side.
[0013]
FIG. 1 shows a method for manufacturing an optical waveguide according to the present invention. A container 2 is filled with a solution 2 in which a photocurable resin and a photosensitizer are mixed (FIGS. 1A and 1B). An optical fiber 3 is inserted into the solution 2 (FIG. 1C), and a laser beam 4 matched or slightly shifted from the absorption peak of the photosensitizer is irradiated through the optical fiber 3 (FIG. 1D). The part irradiated with the laser beam 4 is cured. Since the photosensitizer is decomposed and has a higher refractive index than the uncured portion in the cured portion 5, the laser beam is confined (FIG. 1 (e)), and a substantially linear resin cured portion is obtained. Thereafter, the whole is cured by the UV light 6 (FIG. 1F). When the photosensitizer is a dye, the hardened portion 5 by the laser beam is less colored by the dye than the surroundings.
[0014]
According to FIG. 2, it can be seen that on the shorter wavelength side than the absorption peak, the refractive index decreases as the amount of the photosensitizer increases. Therefore, it is understood that the refractive index of the laser hardened portion becomes higher than that of the surroundings, and functions as an optical waveguide. Thus, the core 7 and the clad 8 are formed, and the polymer optical waveguide device in which the optical fibers are joined is obtained (FIG. 1 (g)).
[0015]
On the other hand, on the long wavelength side, the refractive index increases as the amount of the photosensitizer increases, so that the refractive index of the laser-cured portion becomes lower than that of the surroundings and does not become an optical waveguide. In this way, an optical waveguide that can be connected to the optical fiber without any alignment can be formed. By using a laser diode on the shorter wavelength side than the absorption peak wavelength of the photosensitizer, an optical waveguide directly coupled to the laser diode can be formed.
[0016]
Subsequently, the present invention will be described in more detail with reference to Examples. It is clear that an unlimited number of optical waveguides of the present invention can be obtained by using various photocurable resins and photosensitizers. Therefore, the present invention is not limited to these examples.
[0017]
(Example)
A commercially available acrylate UV curing agent was mixed with a dye of rhodamine 6G dissolved in ethanol as a photosensitizer. This solution was filled in a container 13, and a multimode optical fiber having a core diameter of 50 microns was inserted into the solution. Next, 532 nm all-solid-state laser light (1 mW) was passed through an optical fiber and incident on the solution. At this time, curing along the laser beam was observed. When one hour or more had elapsed from the irradiation with the laser beam, it was found that the cured portion had decolored due to the dye. Thereafter, the whole was irradiated with UV light to cure the whole. Thus, an optical waveguide can be manufactured. When the light of an argon laser 514.5 nm was incident on the 532 nm laser beam hardened portion, it was found that the argon laser beam propagated in the hardened portion. On the other hand, when helium-neon laser 632.8 nm light was incident on the 532-nm laser light cured portion, it was confirmed that the helium-neon laser light was leaking from the cured portion. Thereby, it was confirmed that the optical waveguide was formed on the shorter wavelength side than the absorption peak.
[0018]
[Effects of the present invention]
According to the method for producing a polymer optical waveguide according to the present invention, a polymer optical waveguide having low connection loss with an optical component such as an optical fiber can be realized.
[Brief description of the drawings]
FIG. 1 shows an example of a process for producing a polymer optical waveguide of the present invention. FIG. 2 shows a dispersion curve of the refractive index of a dye.
1: container, 2: solution, 3: optical fiber, 4: laser light 5: cured part, 6: UV light, 7: core, 8: clad

Claims (4)

    A core is formed while irradiating a laser beam having a wavelength of λ1 into a solution in which a photosensitizer that absorbs and decomposes light having a wavelength of λ1 in a photocurable resin is mixed to cure the optical path of the laser beam, and then A method for manufacturing a polymer optical waveguide device, comprising irradiating light for light curing on the entire surface and curing the light to form a clad.     2. The method according to claim 1, wherein the absorption peak wavelength of the photosensitizer is longer than the light wavelength [lambda] 2 to be propagated by the optical waveguide device.     The method according to claim 1, wherein the photosensitizer is a dye.     An optical waveguide device comprising a polymer core and a clad, wherein a concentration of a photosensitizer that absorbs and decomposes laser light having a wavelength of λ1 in the clad is larger than that in the core. Polymer optical waveguide device.

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