JP2001324641A - Connecting parts for optical fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide connecting parts which lessens the optical transmission loss in connecting of an optical fiber and an optical fiber or a semiconductor device and is simple and convenient. SOLUTION: The connecting parts of structures which are mounted at the front end of the optical fibers, have the same external diameter as the external diameter of these front ends and have supporting bodies on their outer peripheries and internally have pliable light transparent body parts are provided. The structures are preferably composed of the light transparent body larger than the cores of the optical fibers and the supporting bodies of the same size as the size of sleeves or ferrules or the supporting bodies in common use as the sleeves or ferrules of the optical fibers in the function and the light transparent body arranged at their end faces. The light transparent bodies are preferably a silicone resin, acrylic resin, epoxy resin, thermoplastic elastomer resin and at least one kind selected from the derivatives of these resins which are preferably 1.35 to 1.55 in refractive index and JIS (type A) <=50 deg. in hardness.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical connecting part of an optical transmission body represented by an optical fiber, and relates to a practical technique for reducing a loss during optical transmission.

[0002]

2. Description of the Related Art The transmission efficiency of an optical transmission line using an optical fiber is greatly affected by the connection loss at the optical connection between the optical fibers in the optical transmission line or between the optical fiber and the optical semiconductor device. The causes of connection loss in these connections include those related to optical fiber positioning, axis misalignment, axis inclination, and gaps between optical fiber end faces, and those related to optical fiber end faces, such as inclination, roughness, and undulation. is there.

In order to effectively eliminate these causes, it is necessary to increase the precision of the connecting device with a complicated structure or to perform advanced polishing treatment on the end face of the optical fiber. These greatly increase costs when connecting optical fibers, and are a major obstacle to widespread use of optical communication systems for information transfer. In order to spread the optical communication system to offices and homes, it is important to be able to easily connect the optical communication system at the same cost as conventional electric wiring, for example.

[0004] Examples of the optical semiconductor device include a light emitting diode, a semiconductor laser, and a photodiode. In general, optical semiconductor devices are designed with high accuracy and are often fixed to the main body of communication equipment. Therefore, it is considered practical to take measures to reduce connection loss on the optical fiber side.

[0005] The present inventors have proposed a connection structure (JP-A-10-111429) in which a flexible light transmitting body is sandwiched between optical connection portions in order to reduce connection loss which is a problem in optical communication. The present inventors have made further studies and found that mounting a simple flexible light transmitting body component at the tip of an optical fiber would enhance the practicality. According to the present invention, anyone can easily and surely make an optical connection with little loss in an office or a general home.

[0006]

SUMMARY OF THE INVENTION The present invention proposes a simple method for reducing optical transmission loss when connecting an optical fiber to an optical fiber or an optical semiconductor device.

[0007]

SUMMARY OF THE INVENTION The present invention aims at reducing optical transmission loss by mounting a simple flexible light transmitting part at the tip of an optical fiber.

The present invention relates to a component for connecting an optical fiber to an optical fiber or an optical semiconductor device. The optical fiber has the same outer diameter as the optical fiber tip and is supported on the outer periphery and has a flexible light inside. It is a connecting component having a structure having a transparent body.

Preferably, the structure of the connecting part is disc-shaped, the light transmitting portion is larger than the core of the optical fiber, and the support is the same size as the sleeve or ferrule. Alternatively, it is preferable that the support has a function of a sleeve or a ferrule of the optical fiber, and a light transmitting body larger than the core of the optical fiber is attached to an end face thereof.

The light transmitting body preferably has a refractive index of 1.35 to 1.55 and a hardness of JIS (A type).
It is preferably at least one selected from a silicone resin, an acrylic resin, an epoxy resin, a thermoplastic elastomer resin and a derivative of these resins having a temperature of 50 degrees or less.

[0011] The connecting part for an optical communication system of the present invention is attached to the tip of an optical fiber. A person attaches and detaches the optical fiber by himself / herself to the connection device, and there is an advantage that a complicated connection is not required and a conventional connection device can be used.

The shape of the connecting part is preferably a disk shape or a cylindrical shape, and can be easily attached to the optical fiber anytime and anywhere. The part has a support on the outside, a flexible light transmitting body on the center of the disk or on the end face of the cylinder. The light transmitting body transmits the signal light to another optical fiber or optical semiconductor device without blocking the signal light larger than the core of the optical fiber.

Examples of the optical fiber include products made by manufacturers such as Shin-Etsu Chemical Co., Ltd. made of quartz, Toray Co., Ltd. made of polymethyl methacrylate resin, and Asahi Glass made of fluorine resin. Examples of the optical semiconductor device include products of domestic manufacturers such as Matsushita Electric Industrial and Hamamatsu Photonics, and products of foreign manufacturers such as Hewlett-Packard and Samsung.

It is preferable that the refractive index of the light transmitting body and the refractive index of the optical fiber are substantially the same, that is, 1.35 to 1.55. If this difference is too large, optical transmission loss due to reflection or the like is caused. still,
The maximum refractive index of the optical fiber is 1.55 made of polymethyl methacrylate resin, and the minimum is 1.35 made of fluororesin.

The light transmitting body is required to be flexible, and its hardness is preferably not more than 50 degrees in JIS (A type).
It is preferably 60 degrees or less in IS (D type). If it is too hard, the adhesion at the time of connection will be insufficient and a gap will be created, resulting in a loss during optical transmission. Suitable resins include silicones, acrylics, epoxies, elastomers, and derivatives thereof. Commercial products can be selected from product catalogs such as Shin-Etsu Chemical, Toagosei, Nippon Kayaku.

FIG. 1 shows an example of a connection component according to the present invention. (1) is a cross-sectional view of a state in which a connection component is mounted on the optical fiber tip portion, as viewed from the side in the connection direction, and (2) is a cross-sectional view a) and a front view b) of the connection component. The connection component 10 is composed of a flexible light transmitting body 11 and a support 12. Fifteen
Is an optical fiber, and 16 is a sleeve or ferrule. This connection part is used by attaching it to the tip of the optical fiber, and if it is frequently attached and detached and damaged, replace it.

FIG. 2 shows another example of the connection component according to the present invention. (1) is a cross-sectional view of the connection component mounting, and (2) is a cross-sectional view a) and a front view b) of the connection component. The connecting member 20 has a light transmitting body 21 and a supporting body 22. 25 is an optical fiber, 26 is a sleeve or a ferrule.

[0018]

Embodiments of the present invention will be described. The present invention
A simple connection component is attached to the tip of the optical fiber to reduce connection loss during optical transmission. The connecting component is a simple structure composed of a flexible light transmitting body and its support.
Hereinafter, specific examples will be described with reference to examples and comparative examples.

[0019]

Embodiment 1 The connecting part shown in FIG. 1 was attached to the tip of a polymethyl methacrylate resin optical fiber (Mitsubishi Rayon) having a refractive index of 1.50, and connected to a transceiver using an existing SMI type connecting device (Nippon Molex). . The connection loss at this time was 0.1 dB. The light transmitting body of the connection component is a transparent epoxy resin cured product (Nippon Kayaku) having a refractive index of 1.50 and JIS (A) of 30 degrees.

In this connection part, the tip of the optical fiber was cut off with a knife to the thickness of the part and mounted. In addition, one surface of the light transmitting body had adhesiveness, and this adhesive surface was attached to the tip of the optical fiber.

[0021]

Example 2 The connecting part shown in FIG. 2 was attached to the tip of a fluorinated resin optical fiber (Asahi Glass) having a refractive index of 1.35, and connected to the same optical fiber using an LC type connecting device (Lucent Technologies). In this case, as the light transmitting body, a fluorine-modified silicone resin (Shin-Etsu Chemical Co., Ltd.) and a refractive index of 1.
37, using JIS (A) 5 degrees, the connection loss between the optical fibers was 0.2 dB.

[0022]

[Comparative Example 1] In the case of Example 1, the connection was made by a conventional method without mounting the connecting parts. In this case, the optical transmission loss at the connection portion was 1.9 dB. That is, it is considered that the connection loss was caused by the effect of the air layer in the gap.

[0023]

Comparative Example 2 A connection was made in the same manner as in Example 2 except that a fluorine-modified silicone resin having a hardness of JIS (A) 60 degrees was used. The connection loss in this case was 1.4 dB. It is considered that the signal light was refracted and scattered because the optical fibers did not adhere to each other because the light transmitting body was hard.

[0024]

According to the present invention, a practical connection part can be provided, and anyone can easily and reliably make an optical connection with little loss in an office or at home. The layman can attach to the optical fiber with his own hand using a conventional connection device. Above all, no complicated work is required, and the versatility that allows quick, inexpensive, and easy connection is useful for the spread of optical communication systems.

[Brief description of the drawings]

FIG. 1 is a diagram showing one example of a connection component of the present invention.

FIG. 2 is a view showing one example of a connection component of the present invention.

[Explanation of symbols]

 10, 20 connecting parts 11, 21 flexible light transmitting body 12, 22 support 15, 25 optical fiber 16, 26 sleeve or ferrule

Claims (5)

[Claims] 1. A component to be optically connected by interposing a flexible light transmitting member between an optical fiber and an optical fiber or an optical semiconductor device. An optical fiber connection component having a structure having the same outer diameter as the portion and having a support on the outer periphery and a light transmitting body inside. 2. The structure of a connecting part having a disk shape, wherein the diameter of the light transmitting portion is larger than the core diameter of the optical fiber, and the outer diameter of the support is the same as that of the sleeve or ferrule. Item 2. An optical fiber connecting part according to Item 1. 3. The structure of the connecting part, wherein the support has a function of a sleeve or a ferrule of an optical fiber, and a light transmitting body larger than the core of the optical fiber is attached to an end face thereof. An optical fiber connection component according to item 1. 4. The light transmitting body has a refractive index of 1.35 to 1.55.
The optical fiber connection component according to claim 1, wherein: 5. The light transmitting body according to claim 1, wherein the light transmitting body is at least one selected from silicone resins, acryl resins, epoxy resins, thermoplastic elastomer resins, and derivatives of these resins having a JIS (A type) hardness of 50 degrees or less. The optical fiber connection component according to claim 1, wherein the component is a seed.