JPH04161908A - Optical ic connecting device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an optical IC coupling device, such as an optical fiber gyro, in which an optical IC and an optical fiber, and an optical IC and a light emitting element are precisely coupled. It is.

(Prior art) As a device for connecting an optical IC and an optical fiber, as shown in FIG. Then, light I
A system in which the CI optical waveguide 1a and the optical fiber 4 are optically coupled has been proposed (Japanese Unexamined Patent Publication No. 59-18
5306 Publication).

Note that the shaded portion 7 in FIG. 5 indicates electrode wiring for inputting and outputting the optical IC.

(Problems to be Solved by the Invention) Generally, extremely high precision alignment of 1 μm or less is required for coupling an optical fiber and an optical waveguide.

However, although the conventional apparatus described above can align the optical fiber with respect to the silicon substrate with high precision, there is a problem in that it is difficult to align the optical IC with respect to the optical fiber with high precision.

Further, in the conventional device described above, the light emitting element is monolithically formed in the optical IC, but in reality, forming the light emitting element in the optical IC requires a very difficult process. Therefore, it is practical to install the optical IC and the light emitting element separately and optically couple them, but in that case, it is also necessary to align the optical IC and the light emitting element with high precision.

The present invention has been made in view of the above points, and is an optical IC.
It is an object of the present invention to provide an optical IC coupling device that can easily and accurately align a light emitting element and an optical fiber, and can minimize optical coupling loss.

(Means for Solving the Problems) In order to achieve the above object, the present invention includes an optical IC in which an optical waveguide is formed, a light emitting element optically coupled to one end of the optical waveguide, and at least one other end of the optical waveguide. An optical IC coupling device having an optical fiber optically coupled to one end, and a substrate on which the optical IC 1 light emitting element and the optical fiber are mounted,
The substrate is formed by photolithography and has concave or convex portions for positioning the light emitting element of the optical IC 1 and the optical fiber.

Further, it is preferable that the optical iC5 and the light emitting element have a convex portion or a concave portion corresponding to the concave portion or convex portion of the substrate.

(Function) By photolithography, the positioning of the concave portion or convex portion is performed with high precision. As a result, by aligning the concave portions or convex portions, the optical IC and the light emitting element, and the optical IC and the optical fiber can be aligned with high precision and easily.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing the configuration of an optical IC portion of an optical fiber gyro according to an embodiment of the present invention. In the figure, 1 is an optical IC, and the optical ICI includes an optical waveguide, a polarizer, a phase modulator,
A photodetector etc. are formed monolithically. Optical ICI
The end surface 11 of the optical ICI is bonded to the silicon substrate 2 with the surface on which each element such as the optical waveguide and polarizer is formed facing the silicon substrate 2, as shown in FIG. 2(b). As shown, the end portion of the optical waveguide 1a is exposed, and the end portion is optically coupled to the light emitting portion 3a of the light emitting element 3 shown in FIG. In addition, the other end face 12 of the optical ICI is also
), the ends of the optical waveguide 1a are exposed at two places (only the - side is shown in the same figure (b), but the other side is the same), and these ends are exposed at two places, as shown in the same figure (a). ), it is optically coupled to the core 4a of the optical fiber 4 disposed in the V-shaped groove 2a of the substrate 2.

The silicon substrate 2 is provided with alignment projections 2b formed by photolithography (also referred to as micromachining Jung method), and the light C1 and light emitting element 3 each have four portions 1b at positions corresponding to the projections 2b. and 3b are provided. These recesses lb and 3b and the V-shaped groove 2a of the substrate 2
The 7-shaped groove 2a and the convex portion 2b are also formed by photolithography.
and recess 1. b and 3b both have a positional accuracy of 1 μm or less.

The optical ICI, the light emitting element 3 and the optical fiber 4 are each A
It is aligned with the concave portions 1b and 3b, the convex portion 2b, and the V-shaped groove 2a, and is fixed to the substrate 2 with an adhesive. Therefore, the relative alignment of the optical ICI, the light emitting element 3, and the optical fiber 4 can be easily performed with high accuracy of 1 μm or less.

As a result, the efficiency of optical coupling between the light emitting element and the optical IC and between the optical fiber and the optical IC can be improved.

Note that the adhesive used is a silicone-based or epoxy-based adhesive that exhibits less shrinkage during curing and less thermal expansion after curing. Further, it is desirable to first fix the light emitting element 3 to the substrate 2, and then fix the optical ICI and the optical fiber 4. This is because the operation of the light emitting element 3 can be checked first, and productivity can be improved.

Further, one electrode of the light emitting element 3 is taken out through the conductive paste 6 poured into the V-shaped groove 2a of the substrate 2, as shown in FIG. 2(a), and the other electrode is taken out by wire bonding from the surface. I'm trying to take it out.

The structure around the notch X of the substrate 2 will be described with reference to FIG. 4 as well.

As mentioned above, the optical ICI is fixed to the silicon substrate 2 with the surface on which each of the elements (optical waveguide, polarizer, etc.) are formed facing down and this surface facing the silicon substrate 2. A portion of the optical ICI No. 2 facing the input/output electrode portion 1c is removed as a notch portion X. Opposite this notch
It is connected to the electrode terminal 5a of and drawn out to the outside.

Therefore, the optical ICI is connected via the wiring pattern on the wiring board 5.
It is possible to input signals to the optical TCI and output signals from the optical TCI.

Although a silicon substrate is used as the substrate 2 in this embodiment, the present invention is not limited to this, and a semiconductor or insulator other than silicon may be used.

Further, the alignment convex portions of the substrate 2 do not need to have the same dimensions and shapes for the optical IC and the light emitting element, but may have different dimensions and shapes.

Alternatively, a concave portion may be formed on the substrate, and a convex portion may be formed on the optical IC and the light emitting element.

Although FIGS. 2 to 4 show that there is a gap between the positioning convex part and the concave part, this is for the purpose of explanation, and in reality, they are fixed without any gap.

(Effects of the Invention) As described in detail above, according to the present invention, the optical IC is
The alignment between the light emitting element or the optical fiber can be performed with high precision and easily, and optical coupling loss can be minimized.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an optical IC portion of an optical fiber gyro according to an embodiment of the present invention, FIG. 2 is a diagram for explaining the coupling state between the end face of the optical IC and a light emitting element, and FIG. is light I
FIG. 4 is a sectional view taken along the line 1--■ in FIG. 1, and FIG. 5 is a diagram illustrating the prior art. 1. Optical IC 12/board, 3. Light emitting element, 4. Optical fiber, 2b: alignment convex portion, lb, 3b: alignment recess.

Claims (1)

[Scope of Claims] 1. an optical IC in which an optical waveguide is formed, a light emitting element optically coupled to one end of the optical waveguide, an optical fiber optically coupled to at least another end of the optical waveguide; optical IC,
In an optical IC coupling device having a substrate on which a light emitting element and an optical fiber are attached, the substrate is formed by photolithography and has a recess or a protrusion for positioning the optical IC, the light emitting element, and the optical fiber. An optical IC coupling device comprising: 2. The optical IC coupling device according to claim 1, wherein the optical IC and the light emitting element have a convex portion or a concave portion corresponding to the concave portion or convex portion of the substrate.