JPH05249340A - Coupling device for optical parts - Google Patents

Abstract

PURPOSE:To provide the coupling device which decreases the laborious operations to enhance coupling efficiency in coupling of optical parts using an optical waveguide, aligns the optical axes of the optical waveguide and the optical parts with no adjustment and executes the coupling with the high efficiency while suppressing coupling losses. CONSTITUTION:The optical waveguide 20 is formed on the plane in the central part of a silicon substrate 1. A guide groove 5 for a laser and guide groove 4 for an optical fiber which are aligned in optical axes are constituted on the same substrate 1 by holding the optical waveguide 20 therebetween. A guide 5 for the laser installed with a semiconductor laser and the optical fiber 6 are disposed in the respective guide grooves 5, 4. As a result, the positions of the guide 6 for the laser and the optical fiber 7 are fixed by the respective guide grooves 5, 4 and since the optical waveguide is integrally formed on the substrate 1, there is no need for aligning the optical axes and adjusting the incident angle of light on the optical waveguide with high accuracy. The coupling losses are thus suppressed and the coupling with high efficiency at an increased extinction ratio is executed. Since the mechanical strength is high and the mis-registration after fixing is hardly generated, the deterioration in the coupling efficiency is prevented and the high reliability is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coupling device for optical components using an optical waveguide in the field of optical communication.

[0002]

2. Description of the Related Art In a method of coupling optical components using optical waveguides, it is necessary to match the optical axes of the optical components and the optical waveguides in order to suppress coupling loss. For this reason,
In the conventional bonding method, the components are finely moved and adjusted so that the coupling loss is reduced, and the components are fixed with an ultraviolet curable resin or the like. Regarding the specific contents of the conventional technology for optical coupling, the 1989 IEICE Spring National Convention No. It is described in C-516.

[0003]

When coupling a pair of optical components by using an optical waveguide, for example, in coupling a semiconductor laser and an optical fiber, the optical waveguide and the semiconductor are combined in order to suppress coupling loss. Adjustments are required to align the optical axes of the laser and the optical fiber. Therefore, it is indispensable to make the semiconductor laser emit light and finely move the semiconductor laser and the optical fiber vertically and horizontally so that the coupling loss becomes low, and this work requires a lot of labor and time.

In view of the above problems, it is an object of the present invention to align the optical axes of the optical waveguide and the optical component without adjustment, and to perform highly efficient coupling with suppressed coupling loss.

[0005]

In order to solve the above-mentioned problems, a guide groove for installing a pair of optical components is formed on the same substrate with an optical waveguide integrally formed with the substrate sandwiched between the guide grooves. The feature is that each optical component is arranged.

[0006]

According to the present invention, since the guide groove for a pair of optical components to be optically coupled can be formed with high accuracy on the substrate integrally formed with the optical waveguide, the optical component can be set at a predetermined installation position. Therefore, the angle of incidence of light on the optical waveguide and the optical axis of the optical component can be aligned simply by inserting the optical component into the guide groove without adjusting the component while finely moving it.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a coupling device for a semiconductor laser and an optical fiber using an optical waveguide.

The optical waveguide 20 is formed integrally with the substrate 1 on the central plane of the silicon substrate 1. Then, the laser guide groove 5 and the optical fiber guide groove 4 aligned with the optical axis of the optical waveguide 20 are sandwiched between the optical waveguide 20 and the same substrate 1
Laser guide 6 configured as above and equipped with a semiconductor laser
And the optical fiber 7 are arranged in the respective guide grooves 5 and 4 (FIG. 1). As a result, the positions of the laser guide 6 and the optical fiber 7 are determined by the respective guide grooves 5, 4.
Moreover, since the optical waveguide 20 is integrally formed on the substrate 1, the optical component is inserted into the guide groove by highly accurate optical axis alignment between the optical waveguide 20 and the active layer 61 of the semiconductor laser and the core of the optical fiber 7. You can do just that.

2 to 4 are schematic views of steps of manufacturing a substrate in the embodiment of the optical component coupling apparatus described above. Hereinafter, description will be given with reference to the drawings. In the actual process, a silicon wafer is used as a unit for processing, and a large number of devices are manufactured on a single wafer as if a semiconductor IC chip is manufactured, and then divided into individual chips (optical coupling device) by dicing. To do. In the following description, for convenience, the process will be described with one chip as a processing unit.

First, the silicon substrate 1 (2 mm × 30 m
After the surface treatment (FIG. 2 (b)) on the plane of (m), approximately half the area from the center is etched, the optical waveguide layer 2
Are deposited (FIG. 2C). Next, after forming a pattern (not shown) by photolithography, dry etching (20 sccm, 2.0 Pa) by C ₂ F ₆ is performed to form the optical waveguide 20 from the optical waveguide layer 2 (FIG. 2).
(D)). The cladding layer 3 is deposited on the optical waveguide 20 (FIG. 3 (e)). Then, by dry etching with SF ₆ (20 sccm, 5.0 Pa), the width of 0.
An optical fiber guide groove 4 having a width of 125 mm and a depth of 0.112 mm is formed (FIG. 3 (f)), and then a laser guide groove 5 having a width of 0.3 mm, a length of 0.3 mm and a depth of 0.05 mm is formed. (FIG. 3 (g)). At this time, the guide grooves 5 and 4 are configured such that the optical axis of the optical waveguide 20 and the optical axes of the laser guide 6 and the optical fiber 7 to be installed coincide with each other. Here, the cladding layer 3 is a guide groove 4 for optical five.
Also serves as a part of.

Then, the laser guide 6 is separately manufactured as follows. An optical component substrate having a semiconductor laser is protected by a 0.3 mm wide area centered on the optical axis and has a height of 0.05 mm.
0.3m after forming a step of mm by etching method
It is cleaved to a length of m perpendicular to the optical axis, and this is used as a laser guide 6 (FIG. 4 (h)). Then, the optical fiber 7 prepared separately from the laser guide 6 is placed in each of the guide groove 5 and the guide groove 4 and fixed by solder and ultraviolet curable resin (FIG. 4 (i, j)).

According to this process, since the guide grooves 4 and 5 are formed on the same substrate 1 as the optical waveguide 20 by the etching method, it is possible to reduce the error of the deviation of the optical axis. Together with this, the optical waveguide 2 formed by the etching method
Since the dimensional error between 0 and the laser guide 6 is small, extremely efficient optical coupling can be performed.

The present invention is not limited to the above-described embodiment, but various modifications can be made.

For example, the coupling of the optical components forming a pair is not limited to one-to-one, but may be coupling in a plurality of plural optical components such as one-to-two coupling. The coupling configured in the waveguide 20 may be used. Further combined with these, the optical waveguide 20 integrally formed with the substrate
Is not limited to simple waveguides, but it can also be used for electrical, acoustic, magnetic, nonlinear,
A waveguide type device using each optical effect of heat, for example, a device having a function of a waveguide type device forming a phase modulator or a branch switch may be used. Further, the end face of the optical waveguide may be processed into a round shape so as to have a lens function.

Further, the optical parts are not limited to the semiconductor laser and the optical fiber, and for example, the optical waveguide and the optical fiber, or the semiconductor laser and the optical waveguide may be coupled on the substrate.

Further, the laser guide groove 5 is processed to be longer than the laser guide 6 in the optical axis direction, and each optical component can be moved in the optical axis direction in order to finely adjust the distance from the optical waveguide. Is also good.

In the embodiment, C ₂ F ₆ (dry) is used as an etching material for processing an optical waveguide, and S is used for processing a silicon substrate.
Although F ₆ (dry) is used, the etching material is not limited to this and may be, for example, HF (wet) or KOH (wet). Further, the optical component arranged in the guide grooves 4 and 5 is not limited to the optical component alone, but a guide of the optical component main body may be produced as necessary as in the embodiment, and the guide and the optical component may be combined. good.

[0018]

As described above, according to the present invention, it is possible to perform highly efficient coupling with suppressed coupling loss without finely adjusting the components for adjustment. Further, since the mechanical strength is high and the positional deviation after fixation is unlikely to occur, deterioration of the coupling efficiency can be prevented and high reliability can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an embodiment of the present invention.

FIG. 2 is a schematic view of a process of manufacturing a substrate according to an example of the present invention.

FIG. 3 is a schematic view of a process of manufacturing a substrate according to an example of the present invention.

FIG. 4 is a schematic view of a process of manufacturing a substrate according to an example of the present invention.

[Explanation of symbols]

1 ... Silicon substrate, 2 ... Optical waveguide layer, 20 ... Optical waveguide,
3 ... Clad layer, 4 ... Optical fiber guide groove, 5 ... Laser guide groove, 6 ... Laser guide having semiconductor laser, 61 ... Active layer of semiconductor laser, 7 ... Optical fiber.

Claims (1)

[Claims] 1. An optical waveguide integrally formed with a substrate is sandwiched between
An optical component coupling device, characterized in that a pair of optical component installation guide grooves are formed on the same substrate, and each optical component is arranged in the guide groove.