JPH054110U - Connection structure between optical fiber and optical waveguide - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a connection structure for an optical fiber and an optical waveguide that facilitates connection of the optical fiber and the optical waveguide and adjustment of the optical axis between them, and also easy readjustment when an optical axis shift occurs. To provide. [Structure] A cylindrical first optical fiber holder 23 attached to an end of an optical fiber 20, and a through hole 3 formed of a magnet block into which the first optical fiber holder 23 is inserted.
And a second optical fiber holder 30 provided with 1.
Metal plates 17 and 19 are attached to the end surface of the optical waveguide substrate 11, and the second optical fiber holder 30 is attached to the metal plates 17 and 19.
Are joined by their magnetic force. The first optical fiber holder 23 having the optical fiber 20 fixed therein is inserted into the through hole 31 of the second optical fiber holder 30 to join the end face of the optical fiber 20 and the end face of the optical waveguide 13.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a connection structure for an optical fiber and an optical waveguide.

[0002]

[Prior art]

 In recent years, optical waveguides have been prototyped and used in various fields such as various sensors and external modulators for optical communication. Since these optical waveguides are usually configured to operate in a single mode, it is desirable to have a so-called pigtail type mounting structure in which the optical waveguide and the single mode optical fiber are combined and integrated. ing.

By the way, conventionally, an optical fiber is connected to an optical waveguide by abutting an optical fiber on an end face of the optical waveguide and fixing both by integrally fixing them with an adhesive.

[0004]

[Problems to be solved by the device]

 However, according to the above conventional connection structure, when the optical fiber and the optical waveguide are fixed with an adhesive and the adhesive is not completely solidified yet, if stress is applied to the connection, There is a problem in that the connection portion is displaced (optical axis displacement), which reduces the optical coupling efficiency between the two.

On the other hand, if the optical fiber and the optical waveguide are fixed while the optical axis is still displaced, there is a problem that the optical axis between them cannot be readjusted.

The present invention has been made in view of the above points, and it is easy to connect the optical fiber and the optical waveguide and to adjust the optical axis between them, and also to easily readjust when the optical axis shifts. A connection structure for an optical fiber and an optical waveguide is provided.

[0007]

In order to solve the above problems, the present invention provides an optical fiber 20 and an optical waveguide that connect an end surface of an optical fiber 20 and an end surface of an optical waveguide 13 formed in an optical waveguide substrate 11. 13, a cylindrical first optical fiber holder 23 attached to the end of the optical fiber 20 and a through hole 31 for inserting the first optical fiber holder 23 or a block of magnets. A second optical fiber holder 30 having a groove 38 is provided, and metal plates 17 and 19 are attached to the end surface of the optical waveguide substrate 11, and the second optical fiber holder is attached to the metal plates 17 and 19. The tool 30 is joined by its magnetic force, and the first optical fiber holder 23 having the optical fiber 20 fixed therein is inserted into the through hole 31 or groove 38 of the second optical fiber holder 30 to insert the end face of the optical fiber 20. Bonding the end face of the optical waveguide 13.

[0008]

[Action]

 The second optical fiber holder 30 can be detachably connected to the end face of the optical waveguide substrate 11 by magnetic force. Therefore, the connection between the optical waveguide 13 and the optical fiber 20 and the optical axis adjustment become easy, and the readjustment when the optical axis shift occurs can be performed.

Since the optical fiber 20 is once fixed to the first optical fiber holder 23 and then fixed to the second optical fiber holder 30, the optical fiber is directly fixed to the second optical fiber holder 30. Compared with the case, the bonding strength of the optical fiber 20 to the second optical fiber holder 30 is increased. When the optical fiber 20 is broken, it can be easily repaired by simply removing the first optical fiber holder 23 from the second optical fiber holder 30 and replacing it.

[0010]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a first embodiment of the present invention. As shown in the figure, the optical fiber-optical waveguide connection structure according to this embodiment includes an optical waveguide substrate 11 having an optical waveguide 13 provided therein, an optical fiber 20, and a first optical fiber holder 23. , And the second optical fiber holder 30. Each component will be described below.

The optical waveguide substrate 11 has a concave portion 15 in a portion of the end face where the optical waveguide 13 is exposed, and metal plates 17 and 19 are attached to both sides of the concave portion 15.

The optical fiber 20 is in a state where the cladding is exposed by peeling off the coating. The first optical fiber holder 23 is formed into a cylindrical shape, and the optical fiber 20 is fixed inside the holder. The end face of the optical fiber 20 is exposed at the end face of the first optical fiber holder 23.

The second optical fiber holder 30 is provided with a circular through hole 31 into which the first optical fiber holder 23 is inserted, and a concave portion of the optical waveguide substrate 11 is formed on one side surface of the second optical fiber holder 30. It is configured by providing a convex portion 33 having a shape fitting with 15. The side surfaces on both sides of the convex portion 33 are formed in a flat shape so as to contact the metal plates 17 and 19 of the optical waveguide substrate 11. The second optical fiber holder 30 is entirely made of magnet.

In order to join the end surface of the optical fiber 20 to the end surface of the optical waveguide 13, first, the second optical fiber holder 30 is connected to the end surface of the optical waveguide substrate 11. At this time, since the second optical fiber holder 30 is a magnet, the second optical fiber holder 30 is attracted to the metal plates 17 and 19, and both are firmly attached. At this time, the convex portion 33 provided on the second optical fiber holder 30 fits into the concave portion 15 provided on the end face of the optical waveguide substrate 11, so that both are securely fixed at a predetermined position.

Next, the first optical fiber holder 23 having the optical fiber 20 attached is inserted into the through hole 31 provided in the second optical fiber holder 30, and the end face of the first optical fiber holder 23 is attached to the end face of the optical waveguide substrate 11. Abut. As a result, the end face of the core of the optical fiber 20 contacts the end face of the optical waveguide 13. The state at this time is shown in FIG. Then, the second optical fiber holder 30 is moved and aligned in the direction of arrow A shown in FIG. 1 to align the optical axis of the optical waveguide 13 with the optical axis of the core of the optical fiber 20, and then the first optical fiber. The fiber holder 23 is fixed to the second optical fiber holder 30 by soldering or adhesive. This completes this connection work.

Since the optical waveguide 13 and the optical fiber 20 are connected by using the magnetic force as described above, the connection work is facilitated and the time required for the optical axis alignment can be greatly shortened, and the optical waveguide 13 and the optical fiber 20 are not aligned after being aligned. In case of occurrence of realignment, realignment can be easily performed.

Further, the optical fiber 20 is securely fixed to the centering position by the first and second optical fiber holders 23 and 30, and the second optical fiber holder 30 is reliably magnetized by the optical waveguide substrate 11. Since the optical fiber 20 is fixed to the optical fiber 20, even if stress or the like is applied to the optical fiber 20, an optical axis shift occurs between the optical fiber 20 and the optical waveguide 13 when the first and second optical fiber holders 23 and 30 are bonded. It does not occur (in the past, the connection between the optical waveguide and the optical fiber was fixed directly with an adhesive, so if stress is applied during bonding, the optical axis will easily shift).

Since the optical fiber 20 is once fixed to the first optical fiber holder 23 and then fixed to the second optical fiber holder 30, the optical fiber 20 is directly fixed to the second optical fiber holder 30. The bonding strength between the optical fiber 20 and the second optical fiber holder 30 is increased as compared with the case where the optical fiber 20 and the second optical fiber holder 30 are fixed. Therefore, when the optical fiber 20 is directly connected to the second optical fiber holder 30, the optical fiber 20 is easily broken at the joint due to the stress generated between the two, but once the optical fiber 20 is connected to the first optical fiber holder 30. If fixed to the optical fiber holder 23, the optical fiber 20 will not easily break even if stress is applied. Further, even when the optical fiber 20 is broken, it can be easily repaired by simply removing the first holding tool 23 from the second holding tool 30 and replacing it, so that the repair work is easy and the cost can be reduced.

In the above embodiment, when the first optical fiber holder 23 is made of metal or magnet, it is adsorbed by the second optical fiber holder 30, so that they can be temporarily fixed easily. The Rukoto.

FIG. 3 is a view showing another embodiment of the present invention. In the embodiment shown in the figure, unlike the embodiment shown in FIG. 1, the end face of the optical waveguide substrate 11 'is not provided with the recessed portion 15 but has a flat surface shape, and the second optical fiber holder 30 is provided. ′ Is not provided with the convex portion 33, and has a planar shape. According to this structure, the second optical fiber holder 30 'can be moved in the two axial directions of arrow A and arrow B in the figure, and the degree of freedom of alignment is increased.

FIG. 4 is a view showing still another embodiment of the present invention. In the embodiment shown in the figure, the second optical fiber holder 30 "is formed in a step shape so as to be movable in the arrow B direction shown in the figure, and the through hole 31" is formed in a rectangular shape. Has been done. On the other hand, the first optical fiber holder 23 "is also formed in the shape of a quadrangular prism. Incidentally, the first optical fiber holder 23" is inserted into the through hole 31 "and moved only in the direction of arrow A shown in FIG. It is configured in a shape that allows

That is, according to this embodiment, the first and second optical fiber holders 23 ″ and 30 ″ allow the arrows A and B to move in the two axial directions, and thus the degree of freedom of alignment. Will increase.

FIGS. 5A and 5B are views showing still another embodiment of the present invention. As shown in the figure, by providing a plurality of through holes 31a, 31b in the second optical fiber holders 30a, 30b, the optical fibers 20a, 20b to which a large number of the first optical fiber holders 23a, 23b are attached are attached. Can be connected at the same time. Therefore, a large number of optical fibers can be easily connected to a large number of optical waveguides only by connecting this to a multiport optical waveguide (not shown). In this case, it is not necessary to change the standard of the first optical fiber holders 23a and 23b, so that the productivity is improved.

FIG. 6 is a diagram showing another embodiment of the present invention. In the figures (a) and (b), the optical fibers 20c, d, 30c, d according to the present invention are used on both end surfaces of the optical waveguide substrate 11c. It is a figure which shows the example which connected d, The figure (a) shows the case where TE mode is selected, and the figure (b) shows the case where TM mode is selected. In the present invention, a metal plate (not shown) is attached to the end face of the optical waveguide substrate 11c, and the second optical fiber holders 30c and 30d are bonded to the metal plate by magnetic force. As shown in (a) and (b), the connection direction of the second optical fiber holders 30c and 30d to the optical waveguide substrate 11c can be horizontal or vertical. Therefore, the TE mode and the TM mode can be freely selected by changing the connecting direction of the second optical fiber holders 30c and 30d as shown in FIGS.

FIG. 7 is a view showing still another embodiment of the present invention. As shown in the figure, when the optical waveguide 13e is provided on the upper surface of the optical waveguide substrate 11e, a V groove 38 is provided on the upper surface of the second optical fiber holder 30e, and the first groove is provided in the V groove 38. The optical fiber holder 23e may be inserted.

In each of the above-described embodiments, the second optical fiber holder is composed of a magnet, and a metal plate is attached to the end face of the optical waveguide substrate. The optical fiber holder may be made of metal and a magnet may be attached to the end face of the optical waveguide substrate.

[0027]

[Effect of the device]

 As described in detail above, the connection structure of the optical fiber and the optical waveguide according to the present invention has the following excellent effects. The connection between the optical fiber and the optical waveguide and the adjustment of the optical axis are easy, and not only the connection with high optical coupling efficiency is possible, but also the time required for the optical axis alignment can be significantly reduced.

When the optical axis shift occurs at the connecting portion between the optical fiber and the optical waveguide, the readjustment becomes easy.

Since the optical fiber is once fixed to the first optical fiber holder and then fixed to the second optical fiber holder, when the optical fiber is directly fixed to the second optical fiber holder. In comparison, the joint strength between the optical fiber and the second optical fiber holder is increased. That is, when the optical fiber is directly connected to the second optical fiber holder, the optical fiber is easily broken at the joint due to the stress generated between the two, but once the optical fiber is connected to the first optical fiber holder. If fixed to the fiber holder, the optical fiber will not break even when stress is applied. Further, even when the optical fiber is broken, it can be easily repaired by simply removing the first optical fiber holder from the second optical fiber holder and replacing it, so that the repair work becomes easy.

[Brief description of drawings]

FIG. 1 is a view showing a first embodiment of a connection structure between an optical fiber and an optical waveguide according to the present invention.

FIG. 2 is a plan view showing a state in which an optical fiber 20 is connected to an optical waveguide 13.

FIG. 3 is a view showing another embodiment of the present invention.

FIG. 4 is a view showing still another embodiment of the present invention.

FIG. 5 is a view showing still another embodiment of the present invention.

FIG. 6 is a view showing still another embodiment of the present invention.

FIG. 7 is a view showing still another embodiment of the present invention.

[Explanation of symbols]

 11 Optical Waveguide Substrate 13 Optical Waveguide 17, 19 Metal Plate 20 Optical Fiber 23 First Optical Fiber Holder 30 Second Optical Fiber Holder 31 Through Hole

Claims (1)

[Claims for utility model registration] [Claim 1] In an optical fiber-optical waveguide connection structure for connecting an end surface of an optical fiber to an end surface of an optical waveguide formed in an optical waveguide substrate, the optical fiber is attached to an end portion of the optical fiber. A tubular first optical fiber holder, and a second optical fiber holder provided with a through hole or groove made of a magnet or metal block into which the first optical fiber holder is inserted, A metal plate or a magnet is attached to an end surface of the optical waveguide substrate, and the second optical fiber holder is magnetically bonded to the metal plate or the magnet attached to the optical waveguide substrate.
Of the optical fiber and the optical waveguide, wherein the end face of the optical fiber and the end face of the optical waveguide are joined by inserting the first optical fiber holder fixed with the optical fiber into the through hole or groove of the optical fiber holder. Connection structure.