JPH0486607A - Method and device for connecting optical waveguide and optical fiber - Google Patents

Abstract

PURPOSE:To simplify a connecting operation by fixing one piece of optical fiber to the groove part of a holder, polishing the side faces of the optical fiber, providing a notched part on the holder and mounting this holder to an optical waveguide. CONSTITUTION:The optical fiber 3 for incidence and the optical fiber 3 for exit are coupled to the substrate type waveguide 1 formed by providing an electric field ion exchange straight optical waveguide 12 on one surface of a substrate 11. Namely, one piece of the optical fiber 3 is inserted and fixed into at least one piece of the groove parts 22 provided on one surface side of the holder 2 and the side faces of the surface side of this optical fiber 3 are polished. Such a notched part 21 where the optical fiber 3 is cut is provided in a part on one surface side of the holder 2 and the holder 2 is fixed to the substrate 11 provided with the optical waveguide 12 by registering the polished surface 33 of the optical fiber 3 and the optical waveguide 12. The connecting operation is extremely simplified and facilitated and the size over the entire part of the optical waveguide 12 including the connecting part to the optical fiber 3 is reduced.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for interconnecting an optical waveguide and an optical fiber, and a connection device therefor.

[Conventional technology]

Substrate-type waveguides and optical integrated circuits used for optical communications, optical signal processing, etc. are usually connected to optical fibers to input and output optical signals. When connecting an optical waveguide and an optical fiber in this way, there are two types of coupling methods: end face direct joining method (butt joint method), lens joining method, etc., prism joining method, and polishing the sides of the optical fiber. There is a side-type coupling method, such as a method in which the polished surface is brought into close contact with the optical waveguide. Among these, for LiNbO3 optical waveguides and optical waveguides using glass substrates where the fields of the optical fiber and optical waveguide are relatively coincident, it is recommended to use the butt joint method as shown in Figures 6 and 7. Common. That is, in this butt joint method, as shown in these figures, the end face of the optical fiber 3 is placed on the side surface of the substrate-type waveguide 1 having the optical waveguide 12 formed on one surface of the substrate 11, and the core 31 of the optical fiber 3 is The optical waveguide 12 and the optical waveguide 12 are brought into close contact with each other while being aligned. However, in the case of this butt joint method,
In order to align the core 31 of the optical fiber 3 and the optical waveguide 12, three translation axes and two tilt axes (
When a plurality of optical waveguides and a plurality of optical fibers are coupled together, adjustment in three axes must be performed, and the alignment is extremely complicated. Furthermore, in order to perform such a coupling, the input and output end faces of the optical waveguide 12 must be polished to a submicron order, which is complicated. Furthermore, the optical fiber 3 is coupled to the end face of the substrate type waveguide 1.
Another drawback is that the bonding area during fixation is small, the adhesive strength is weak, and the strength is unreliable. On the other hand, in the side-type joining method shown in FIGS. 8 and 9, these drawbacks have been improved. A part of the side surface of the fiber 3 is mirror-polished so that a part of the field of the core 31 is radiated, and this polished surface is brought into close contact with the optical waveguide 12 on one surface of the substrate 11 of the substrate-type waveguide 1 to emit light. Emitted field of fiber 3 and optical waveguide 1
2 and fixed with a holder 4. In this case, there is no need to polish the end face of the substrate-type waveguide 1, and alignment only requires aligning two translational axes and one tilting axis, so the work required for connection is considerably greater than that of the butt joint method. It can be made simple.

[Problem to be solved by the invention]

However, even when such a side-type connection method is used, conventionally, optical fibers with polished sides must be attached to the input side and the output side of the optical waveguide, which makes the work complicated. There is a problem. This invention eliminates the complexity of attaching optical fibers with polished sides separately on the input and output sides of an optical waveguide.
An object of the present invention is to provide a method and device for connecting an optical waveguide and an optical fiber.

[Means to solve the problem]

In order to achieve the above object, the method for connecting an optical waveguide and an optical fiber according to the present invention includes a step of inserting and fixing one optical fiber into at least one groove provided on one surface side of the holder. a step of polishing the side surface of the above-mentioned surface side of the above-mentioned optical fiber; a step of providing a notch in a part of one surface side of the above-mentioned holder through which the above-mentioned optical fiber is cut; A holder having a fiber and a notch is placed on a substrate having an optical waveguide on one surface side, and the polished surface of the optical fiber and the optical waveguide are aligned,
and fixing it to one surface of the substrate. In addition, in the optical waveguide and optical fiber connection device according to the present invention that achieves the above object, it has a notch on one surface side, and on both sides of the notch, provided on the one surface. a holder having a groove, two optical fibers each inserted into and fixed in the grooves on both sides of the notch of the holder and having a polished side surface on the one surface side; A substrate provided with an optical waveguide is provided, to which the holder is attached so as to be in contact with the surface on the optical waveguide side and with the optical fiber and the optical waveguide aligned.

[For production]

An optical fiber is fixed in the groove of the holder, the side surface of the optical fiber is polished, a notch is provided in the holder so that the optical fiber can be cut, and the holder is attached to an optical waveguide. By providing the notch in this way, the optical fiber on the input side and the optical fiber on the output side can be separated. That is,
An optical fiber on the input side and an optical fiber on the output side can be formed simultaneously in one holder. In order to attach this holder to the optical waveguide, alignment between the optical fiber and the optical waveguide or the input side and the output side can be done simultaneously in one operation, simplifying the 5 connection operations.
Can do the job easily. In addition, since the optical fiber on the input side and the optical fiber on the output side are integrally formed in one holder, the holder can be made spatially smaller, and the entire optical waveguide component including the output optical fiber coupling part can be made smaller. Not only can it be made more compact, but it also improves the mechanical coupling strength and increases the stability of optical coupling.

【Example】

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view of a connecting device for connecting an optical waveguide and an optical fiber according to an embodiment of the present invention, taken in a longitudinal section along the optical axis and viewed from the side. In this embodiment, an input optical fiber 3 and an output optical fiber 3 are coupled to a substrate type waveguide 1 in which an electric field ion exchange linear optical waveguide 12 is provided on one surface of a substrate 11. As this optical fiber 3, a single mode optical fiber for a wavelength of 1.3 μm was used. As shown in this figure, the holder 2 is made of quartz, and has a notch 21 on one surface side (lower side in the figure).
is provided. Two optical fibers 3 are fixed on both sides of the notch 21, respectively. As will be described later, these optical fibers 3 are inserted into and fixed in U grooves 22 (see FIG. 2) provided on the lower surface of the holder 2, and their lower surfaces are polished to form a polished surface 33 (see FIG. 3). ) is formed. Then, the lower surface of the holder 2 is made to face the upper surface of the substrate-type waveguide 1, so that the holder 2 becomes a substrate-type waveguide! Attached to @1. Here, the lower surface (polished surface 33) of the optical fiber 3 and the upper surface of the optical waveguide 12 are aligned. Such a connection device between an optical waveguide and an optical fiber is manufactured as follows. First, as shown in Figure 2, 1
The single mode optical fiber 3 for the wavelength of 1.3 μm is
One U groove 22 provided on one surface of the quartz holder 2
Insert and glue. Next, as shown in FIG. 3, this optical fiber 3 is mirror-polished on one surface side (upper side in FIG. 3) of the holder 2 to provide a polished surface 33 on the side surface of the optical fiber 3. This polished surface 33 is formed so that the field of light guided through the core 31 is radiated to the outside to some extent. When the entire holder 2 is cut in a plane perpendicular to the optical fiber 3, it becomes as shown in FIG. The cladding 32 part was polished up to The length of the polished side surface of the optical fiber 3 was 15a++. Thereafter, as shown in FIG. 5, a certain area in the center of one surface of the holder 2 is cut away to form a notch 21. The depth of this notch 21 is set to be deep enough to cut the optical fiber 3, and by cutting the optical fiber 3 in this way, the optical fiber 3 on the input side and the optical fiber 3 on the output side are separated. To separate. The length of the remaining polished surface 33 and the length of the notch 21 are determined in consideration of the coupling length with the optical waveguide 12, the size of the functional optical element formed in the optical waveguide 12, and the like. Here, the length of the notch 21 is 511
II11, and polishing surfaces 33 having a length of 5M were left on both sides thereof. 5 Place the optical fiber holding holder 2 made in this way as shown in FIG.
After aligning with 2 and adjusting the bond length, it was fixed with an ultraviolet curing adhesive. In this example, the coupling loss between the optical waveguide 12 and the optical fiber 3 was 2 dB per coupling. As described above, when attaching one holder 2 to the substrate type waveguide 1, the axes of the input side optical fiber 3 and the output side optical fiber 3 are simultaneously aligned with respect to the optical waveguide 12 by adjusting the position. In addition, the input and output sections can be formed from a single side-polished optical fiber, making the work extremely easy. In addition, the size of the entire optical waveguide component including the output optical fiber coupling part can be reduced, and since the holder is integrated on the input side and output side, the coupling strength of the optical fiber is increased due to its large bonding area. This can improve the stability of the bond.

【Effect of the invention】

According to the method and device for connecting an optical waveguide and an optical fiber of the present invention, the connection work becomes extremely simple and easy, and the overall size of the optical waveguide including the connecting portion with the optical fiber can be reduced. At the same time, it is possible to improve the stability of the coupling of the human output optical fiber.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing a connecting device according to an embodiment of the present invention, FIGS. 2, 3, and 5 are perspective views illustrating each step of the connecting method, and FIG. FIG. 6 is a perspective view of the conventional example, FIG. 7 is a longitudinal sectional view of the conventional example, and FIG.
The figure is a perspective view of another conventional example, and FIG. 9 is a longitudinal sectional view of the same conventional example. DESCRIPTION OF SYMBOLS 1... Substrate type waveguide, 11... Substrate, 12... Optical waveguide, 2.4. Holder, 21... Notch, 22...
・U groove, 3-optical fiber, 31...core, 32...cladding, 33.polished surface. Paper 1Ω U Hanawa - Ki θ Color Light Fufuiba Banquet? 9th area of Yamamantle

Claims (2)

[Claims] (1) a step of inserting and fixing one optical fiber into at least one groove provided on one surface side of the holder; a step of polishing a side surface of the above-mentioned optical fiber on the above-mentioned surface side; a step of providing a notch for cutting the optical fiber on a part of one surface of the holder; A method for connecting an optical waveguide and an optical fiber, comprising the steps of: aligning the polished surface of the optical fiber and the optical waveguide, and fixing the optical waveguide to one surface of the substrate. (2) A holder that has a notch on one surface side and grooves provided on the one surface on both sides of the notch, and a holder that is inserted into the grooves on both sides of the notch of the holder. two optical fibers fixed together and having polished side surfaces on the one surface side, and a state in which the one surface of the holder is in contact with the surface on the optical waveguide side, and the optical fibers and the optical waveguide are aligned. An apparatus for connecting an optical waveguide and an optical fiber, comprising a substrate provided with an optical waveguide and to which the holder is attached.