JPH06281826A - Manufacture of quartz-based optical waveguide parts - Google Patents

Abstract

PURPOSE:To provide the manufacturing method for quartz based optical waveguide parts having a guide groove for connecting other optical parts with a guide pin. CONSTITUTION:On a substrate 15, a waveguide core 17a, and a marker part 20 consisting of a waveguide core 17b in which an detaching mask 19 is stuck to the top part form a quartz embedded waveguide 21 embedded and provided in a clad, the marker part 20 is exposed by eliminating selectively the clad in the vicinity of the marker part 20, and subsequently, a guide groove for fitting a pin is carved and provided by using the exposed marker part 20 as a reference for positioning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical waveguide component in which an optical fiber connector or the like is connected to the end face of a guide pin for use.

[0002]

2. Description of the Related Art An optical waveguide component in which a waveguide core having a predetermined pattern is embedded in a clad is used by connecting a single-core or multi-core optical fiber connector to both end faces thereof. The connection method of the optical fiber connector in this case is roughly classified into the following methods.

First, in the first method, as shown in FIG. 1, a waveguide core having a predetermined pattern is formed on a fine adjustment table (not shown) that can be finely moved in a three-dimensional direction. An optical waveguide component 1, an optical fiber arranging tool 4a holding, for example, two input side optical fibers 2a and 2b at both ends thereof, and an optical fiber arranging tool 4b holding, for example, two output side optical fibers 3a and 3b are provided. Set in a state where they are butted. Then, the light from the light sources 5a and 5b is input to the input side optical fibers 2a and 2b, respectively, and the optical power from the output side optical fibers 3a and 3b is measured by the optical power meters 6a and 6b, respectively.

In this state, the optical fiber arranging tool 4a, the optical waveguide component 1, and the optical fiber arranging tool 4b are finely moved to each other.
When the output powers measured by the optical power meters 6a and 6b show the maximum value, it is assumed that the optical axes of the optical waveguides and the optical fiber array tools 4a and 4b are mutually aligned by using an adhesive. Adhere and fix. By the way, this optical axis alignment work requires a lot of time. The reason is
The optical axis alignment after starting the measurement of the optical power is a few minutes, which is a short time.However, the connection between the light source and the optical power meter and the optical fiber performed before that, or the optical fiber for the connection This is because it takes a few tens of minutes to process the terminal.

Further, in the case of the module manufactured by the above-mentioned method, since the optical waveguide component and the optical fiber arranging tool are connected by an adhesive, for example, when a part of the optical fiber is broken, the optical waveguide component itself is connected. Even if nothing goes wrong, the entire module will have to be destroyed. In the second method, as shown in FIG. 2, a waveguide core 8 made of, for example, quartz glass has the same quartz glass (having a higher refractive index than the quartz glass of the core) on a waveguide substrate 7 such as a Si substrate having a predetermined thickness. Is small) from the upper surface of the clad 9 of the optical waveguide component existing in a state of being buried in the clad 9 to the bottom of the substrate 1 by using, for example, a dicer to have a predetermined width and depth. Two grooves 10a, 1 extending in the longitudinal direction
0b is engraved with the above-mentioned optical waveguide core 2 as a positioning reference, and guide pins 11a and 11b having a predetermined diameter are arranged in these grooves 10a and 10b, respectively, and the whole holding plate 1 is provided.
By pressing with 2, the guide pins 11a and 11b are fixed in the grooves 10a and 10b.

The waveguide core 8 of the above-mentioned optical waveguide component
The optical fiber connectors 13 and 13 in which the optical fibers aligned at the same pitch as each core are built in, and the pin holes 13a and 13b are formed coaxially with the guide pins 11a and 11b on both sides are prepared. To be done. When connecting the optical fiber connectors 13 and 13 to both ends of the optical waveguide component,
The guide pins 11a and 11b are connected to the optical fiber connector 13,
The end faces of the optical waveguide component and the end face of the optical fiber connector 13 are brought into contact with each other by inserting them into the pin holes 13a and 13b of 13, and they are pressure-welded to each other using, for example, a spring clip 14.

In this way, the optical axes of the optical waveguide core 8 and the optical fiber of the optical fiber connector 13 coincide with each other, and the optical connection is completed without performing alignment work there. In the case of this unaligned connection method, the grooves 10a, 10 of the optical waveguide component are
As long as b is accurately engraved with the pin holes 13a and 13b of the optical connector 13, it is possible to connect the guide pins only in the groove and the pin hole without performing the optical axis alignment work. Is equipped with. Further, for example, even when a part of the optical fiber is broken, the clip 14 is released to separate the optical waveguide component and the optical fiber connector, and a new optical fiber connector may be pin-fitted, so that the entire module is discarded. There is no need.

[0008]

When the above-mentioned two connection methods are compared, the latter connection method using the guide pin is simple in connection work, and each optical component can be replaced. Therefore, it can be said that it is superior to the former connection method. By the way, in the case of this non-centering connection method, it is indispensable to engrave the guide groove in which the guide pin for fitting is arranged in the optical waveguide component. When the guide pin is arranged in the guide groove, it is necessary that the cross-sectional center of the guide pin coincides with the cross-sectional center of the guide pin hole of the optical fiber connector to be connected with high accuracy.

This guide groove is generally machined by a dicer or the like. However, in the case of silica-based optical waveguide components,
Since both the waveguide core and the clad in which it is embedded are transparent, it is very difficult to visually locate the guide groove engraved by the dicer. Therefore, the guide groove may not be engraved at the proper position, and when the manufactured optical waveguide component is pin-fitted to the optical fiber connector, the optical axes of the respective waveguide cores may not match. That is, the yield of products is very unstable.

The present invention solves the above-mentioned problems in engraving the guide groove of the optical waveguide part to be pin-fitted, and manufactures an optical waveguide part with a guide groove for pin fitting in which the guide groove is engraved in the correct position. The purpose is to provide a method.

[0011]

In order to achieve the above object, in the present invention, a waveguide core and a marker portion composed of a waveguide core having an etching mask attached to the top are provided on a substrate. A silica-based buried waveguide embedded in the clad is formed, the clad near the marker part is selectively removed to expose the marker part, and then the exposed marker part is used as a positioning reference for pin fitting. There is provided a method for manufacturing an optical waveguide component, which is characterized by engraving the guide groove.

[0012]

In the method of the present invention, prior to the engraving of the guide groove, only the visible marker portion of the waveguide core in which light is propagated is selectively exposed from the clad while being buried in the clad. To be Therefore, the guide groove can be stably engraved by using the exposed marker portion as a positioning reference.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention will be described in detail below with reference to the accompanying drawings. As shown in FIG. 3, first, on the substrate 15 made of, for example, Si single crystal, a lower clad layer 16a having a predetermined thickness made of, for example, SiO _{2 is} formed by a flame deposition method.
For example, a core slab layer 17 having a predetermined thickness made of Ti-doped SiO ₂ is sequentially formed.

Then, a photolithography method and, for example, a reactive ion etching method are applied on the lower clad layer 16 so that the waveguide core for light propagation and the waveguide core to be the marker portion remain. The waveguide core 17a and the waveguide core 17b for the marker portion are simultaneously formed (FIG. 4). On the waveguide core, a mask 18 as shown by an imaginary line in which a portion of the waveguide core 17b to be the marker portion is punched out is arranged, and in that state, for example, a-Si is sputtered to guide the mask. The thickness is 1 μm only on the surface of the waveguide core 17b.
A mask 19 of a certain size is attached (FIG. 5). Attached a-
Since the Si mask 19 is opaque, the waveguide core 17
A portion including b and the mask 19 on the surface thereof can function as a visible mask portion 20.

Although the mask 19 may be attached only to the surface of the waveguide core 17b as shown in FIG. 5, the attachment is not limited to such an attachment mode and is attached to the waveguide core 17a. Otherwise, it may be attached near the periphery of the waveguide core 17b. Then, as shown in FIG. 6, the lower cladding layer 16 is again formed by the flame deposition method.
An upper clad layer 16b having the same refractive index as that of a and a predetermined thickness is formed to embed the waveguide core 17a and the marker portion 20 to form an embedded waveguide 21.

After that, of the surfaces 21a of the buried waveguide 21, the surface corresponding to directly above the waveguide core 17a for causing light propagation is, for example, as shown by the phantom line in FIG. By covering with a mask 22 (for example, negative resist: OMR-83 manufactured by Tokyo Ohka Co., Ltd.) and immersing it in a hydrofluoric acid solution in that state, the portion of the embedded waveguide located on the marker portion 20 is changed to the marker portion. Thickness 2 directly above 20
It is removed by etching leaving about μm (FIG. 7).

Then, after removing the mask 22, the surface of the embedded waveguide is removed by about 5 μm by subjecting the entire embedded waveguide to a reactive etching method. As shown in FIG. Is exposed from the buried waveguide. At this time, if the thickness of the upper clad layer 16b of the buried waveguide 21 is made sufficiently thick, it is possible to prevent the waveguide core 17a for causing light propagation from being exposed.

Finally, by operating the dicer with the exposed marker portion 20 as a reference for positioning, as shown in FIG. 9, two guide grooves 23a and 23b are formed on both sides to form a pin fitting guide. An optical waveguide component having a groove is obtained. At this time, the cross-sectional shapes of the guide grooves 23a and 23b are such that when the guide pin is arranged here, the center position of the guide pin is the center position of the guide pin hole formed in the optical fiber connector to be connected. It is controlled to be the same and to be located on the same plane as the center of the waveguide core 17a.

In using this optical waveguide component, as shown in FIG. 10, guide pins 24a and 24b having a predetermined diameter are arranged in the guide grooves 23a and 23b, respectively, and the guide grooves 23a and 23b are formed on them. A lid 25 made of, for example, Si having grooves 25a and 25b engraved at positions corresponding to the positions is covered, and both the optical waveguide component and the lid 25 are bonded or fixed by a mechanical means such as a spring clip. Then, by inserting the protruding portions of the guide pins 24a and 24b into the guide pin holes of the optical fiber connector, unaligned connection is realized.

In the embodiment, the case where the guide groove is formed in one optical waveguide component has been described, but the method of the present invention is not limited to this, and a plurality of guide grooves are formed on one Si wafer, for example. It can also be applied to an individually formed optical waveguide component.

[0021]

As is clear from the above description, according to the method of the present invention, the engraving of the guide groove is visible from the buried waveguide and the positional relationship with the waveguide core is accurately grasped. Since the positioning is performed with the marker portion being used as a reference for positioning, the guide groove can be formed at a correct position and stably, and the incidence of defective products is reduced.

The optical waveguide component with the guide groove can be connected to other optical components without alignment.

[Brief description of drawings]

FIG. 1 is a schematic plan view showing a conventional example in a method of connecting an optical waveguide component and an optical fiber.

FIG. 2 is a perspective view showing a state in which an optical waveguide component and an optical fiber connector are connected by pin fitting.

FIG. 3 is a cross-sectional view showing a state in which a lower clad layer and a core slab layer are formed on a substrate in the method of the present invention.

FIG. 4 is a cross-sectional view showing a state in which a waveguide core is formed.

FIG. 5 is a cross-sectional view showing a state in which a marker portion is formed.

FIG. 6 is a cross-sectional view showing a state where an embedded waveguide is formed.

FIG. 7 is a cross-sectional view showing a state where a buried waveguide is etched with hydrofluoric acid.

FIG. 8 is a cross-sectional view showing a state in which a marker section is exposed from an embedded waveguide.

FIG. 9 is a perspective view showing a state in which a pin fitting guide groove is engraved.

FIG. 10 is a perspective view showing a state where guide pins are arranged on the optical waveguide component.

[Explanation of symbols]

 15 Substrate 16a Lower Clad Layer 16b Upper Clad Layer 17 Core Slab 17a Waveguide Core 17b for Propagating Light Waveguide Core for Attaching a Marker 18 Mask 19 a-Si (Etching Mask) 20 Marker Part 21 Embedded Waveguide 21a Embedded Surface of waveguide 21 22 Mask 23a, 23b Guide groove for pin fitting 24a, 24b Guide pin 25 Lid 25a, 25b Groove of lid 25

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kuji Yanagawa 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Within Furukawa Electric Co., Ltd. (72) Innovator Nobuo Tomita 1-1-6, Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation

Claims (2)

[Claims] 1. A silica-based buried waveguide in which a waveguide core and a marker portion composed of a waveguide core having an etching mask attached to the top thereof are buried in a clad is formed on a substrate, and the marker portion is formed. A silica-based optical waveguide component characterized by selectively removing a clad in the vicinity to expose the marker portion, and then engraving a guide groove for pin fitting with the exposed marker portion as a positioning reference. Production method. 2. The marker portion comprises a silica-based lower clad layer and a silica-based core slab that are sequentially formed on a substrate, and then the silica-based core slab is subjected to photolithography and etching to form a waveguide core, The method for manufacturing a silica-based optical waveguide component according to claim 1, wherein a visible etching mask is attached to the surface of the waveguide core to be the marker portion.