KR20100064277A - Optical connection device between the plastic and silica optical fiber - Google Patents

Abstract

PURPOSE: An optical coupler between different kind optical fibers is provided to minimize an insertion loss of an optical signal due to a diameter difference of the optical signal. CONSTITUTION: A first optical fiber(10) transfers a signal ray. A second optical fiber(20) has a different refraction index with the first optical fiber and transfers the signal ray delivered to the first optical fiber. A fixing unit(30) protects a part of the first optical fiber and the second optical fiber and fixes the first optical fiber and the second optical fiber.

Description

Optical coupler between the plastic and silica optical fiber

The present invention relates to an optical coupler, and in particular to an optical coupler for connecting different kinds of optical fibers.

The present invention is derived from the research conducted as part of the leading technology test support project of the Ministry of Knowledge Economy and the Ministry of Information and Communication Research and Development.

In many optical devices such as laser diodes, photodiodes, optical sensors, optical switches, and the like, high coupling efficiency with optical fibers is required. In general, when the optical components and modules are packaged, the light propagated from the optical fiber performs an optical coupling that is incident on the optical device as parallel light by a ball lens or a GRIN lens.

However, such conventional optical coupling requires that the alignment of the optical axis of the optical fiber and the lens must be controlled within the submicron range, which increases the cost of the assembly apparatus and the like. Therefore, research is being conducted to increase the coupling efficiency with optical components, and most of them form a lens at the end of a single-mode fiber by using a machining process or an etching process or at the end of an optical fiber by using arc discharge. A method of combining a ball lens or a refractive index distributed lens is used. However, most of these methods have been studied as a method for homogeneous optical fiber connection, and there is a problem that optical axis position alignment should be considered every time for optical coupling.

SUMMARY OF THE INVENTION The present invention is derived from this background, and an object of the present invention is to provide an optical coupler that minimizes the loss in optical signal transmission between two kinds of optical fibers having different core sizes.

In addition, an object of the present invention is to provide an optical coupler that is easy to connect between different optical fibers.

The technical problem is that the first optical fiber for transmitting the signal light; A second optical fiber having a refractive index different from that of the first optical fiber and transmitting and receiving the signal light transmitted to the first optical fiber; And a fixing part formed to enclose at least a portion of the first optical fiber and the second optical fiber to couple and fix the first optical fiber and the second optical fiber. .

According to the present invention, there is an effect that the connection between the heterogeneous optical fibers is easy even without fusion and fine processing between the plastic optical fiber and the quartz-based optical fiber. In addition, by grinding into a convex lens type, it is possible to minimize the insertion loss of the optical signal that can be generated due to the diameter difference of the heterogeneous optical fiber.

The foregoing and further aspects of the present invention will become more apparent through the preferred embodiments described with reference to the accompanying drawings. Hereinafter, the present invention will be described in detail so that those skilled in the art can easily understand and reproduce the present invention through these embodiments.

1 is an exemplary view showing the configuration of an optical coupler according to an embodiment of the present invention.

As shown, an optical coupler according to an embodiment of the present invention includes a first optical fiber 10, a second optical fiber 20, and a fixing part 30.

The first optical fiber 10 transmits an optical signal incident from the outside to the second optical fiber 20 or outputs an optical signal incident from the second optical fiber 20 to the outside. The second optical fiber 20 is another type of optical fiber that differs in refractive index from the first optical fiber 10. In one embodiment, the first optical fiber 10 may be a plastic optical fiber and the second optical fiber 20 may be a quartz optical fiber.

In one aspect of the present invention, when the first optical fiber 10 is larger in diameter than the second optical fiber 20, the portion where the first optical fiber 10 is coupled to the second optical fiber 20 is convex lens type. To be polished. In this case, the convex lens type may be formed by a wet etching method or an optical polishing method.

In general, when light travels from a small optical fiber to a large optical fiber, there is no problem in connection for optical transmission. However, when the optical signal has to be inserted from the optical fiber having the large inner diameter to the small optical fiber, the size of the optical fiber has a great influence on the optical signal loss. That is, in order to reduce the loss of the optical signal due to the mode mismatch, the shape of the optical fiber spacing mode should be symmetrical and match each other.

That is, the insertion loss of the optical signal according to the optical fiber diameter difference can be minimized by grinding one end of the first optical fiber having a larger diameter than the second optical fiber 20 with the second optical fiber 20 in a convex lens shape.

In addition, a lens having a spherical surface into which light is incident may have less spherical aberration than a lens having a flat surface, thereby reducing alignment. Therefore, the light coupling efficiency can be increased.

On the other hand, in this case, in order to minimize the light loss in the coupling portion by combining the first optical fiber 10 and the second optical fiber 20, it is preferable to align the alignment and distance so as to focus as much light as possible. That is, the focal length in the form of a convex lens of the first optical fiber is preferably implemented to be optimized to minimize light loss.

Opposite sides of the first optical fiber 10 and the second optical fiber 20 are coupled to each other by splicing with the external optical fiber. The splicing process is to heat and slightly melt the two strands of the optical fiber, which can be performed using a device called Fusion Splicer. The optical fiber that is externally connected to the first optical fiber 10 is an optical fiber having the same diameter as the first optical fiber 10, and the optical fiber that is externally connected to the second optical fiber 20 has an optical fiber having the same diameter as the second optical fiber 20. Is implemented.

The fixing part 30 is formed to surround at least a portion of the first optical fiber 10 and the second optical fiber 20 to fix a portion where the first optical fiber 10 and the second optical fiber are coupled. In the present embodiment, the fixing part 30 fixes the coupling structure of the two optical fibers in a structure capable of tightly wrapping and supporting the first optical fiber 10 and the second optical fiber 20 whose optical axis positions are aligned. Accordingly, there is an effect of facilitating the connection between the first optical fiber 10 and the second optical fiber of different types without the fusion and fine processing process. In one embodiment, the fixing part 30 may be implemented in a plastic or metal material. However, the present invention is not limited thereto.

In addition, a coupling member 40 having a larger refractive index than the first optical fiber 10 and the second optical fiber 20 is further included in the portion where the first optical fiber 10 and the second optical fiber 20 are coupled. In the present embodiment, the coupling member 40 may be implemented as a refractive index matching solution having a specific refractive index. That is, by attaching or depositing the coupling member 40, the focusing distance of the emitted light can be increased, so that the coupling between the first optical fiber 10 and the second optical fiber 20 can be performed more easily and efficiently. Derived.

So far I looked at the preferred embodiments of the present invention. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown in the claims, and all differences within the scope equivalent thereto should be construed as being included in the present invention.

1 is an exemplary view showing the configuration of an optical coupler according to an embodiment of the present invention.

Claims (5)

A first optical fiber for transmitting signal light; A second optical fiber having a refractive index different from that of the first optical fiber and transmitting and receiving the signal light transmitted to the first optical fiber; And And a fixing part formed to enclose at least a portion of the first optical fiber and the second optical fiber in order to couple and fix the first optical fiber and the second optical fiber. The method of claim 1, The first optical fiber is an optical coupler between different optical fibers, characterized in that the portion coupled to the second optical fiber is polished in a convex lens shape. The method of claim 1, And a coupling member having a refractive index higher than that of the optical fibers, at a portion where the first optical fiber and the second optical fiber are coupled to each other. The method of claim 1, And the first optical fiber is a plastic optical fiber. The method of claim 1, The second optical fiber is an optical coupler between heterogeneous optical fibers, characterized in that the quartz optical fiber.

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