JP2002350662A - Hybrid type waveguide module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hybrid type waveguide module which has the whole waveguide element made resistive to an external shock and is reducible in manufacture cost by protecting a filter part, an LD part, and a PD part against external environment. SOLUTION: A plane substrate waveguide element 6 is fixed on a base 7, a block 19 for connecting an optical fiber 20 is fixed on the waveguide element 6, and optical components such as a laser diode 14 and a photodiode 15 are mounted on the waveguide element 6; and those waveguide element 6 and the components 14 and 15 are all covered with a lid 22 fixed to the base 7 to constitute the hybrid waveguide type module. The lid 22 with which the block 19 is united is formed and the tip surface 25 of the lid 22 on the block 19 side is slanted at a prescribed angle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waveguide module, and more particularly to a hybrid waveguide module having a planar substrate type waveguide on which optical components such as a dielectric multilayer film filter, an LD, and a PD are mounted.

[0002]

2. Description of the Related Art In recent years, in the field of communication using optical fibers, bidirectional communication using light having a wavelength of 1.3 μm has become mainstream.

In order to perform the bidirectional communication, a hybrid waveguide module is an indispensable device.

FIGS. 4A to 4E show the structure of a conventional hybrid waveguide module.

[0005] As shown in FIG.
A clad layer 2 is deposited thereon, and a core layer 3 is deposited on the clad layer 2.

The core layer 3 is subjected to a photolithographic technique and an etching technique, and as shown in FIG.
Is formed. A clad layer 5 is further deposited on the waveguide 4 thus formed.

As shown in FIG. 4D, the waveguide element 6 is adhered to the base 7 and is fixed to the base 7 with the cover 8 covering the entire module. The adhesive for fixing the waveguide element 6 and the base 7 is a thermosetting epoxy resin.
The adhesive for fixing the lid 8 and the base 7 is a thermosetting epoxy resin. The lid 8 has a function of withstanding the external impact of the entire waveguide element 6.

Then, as shown in FIG. 4E, a groove 9 is formed on the waveguide element 6, and a filter 10 is inserted into the groove 9.

The dimensions of the groove 9 to be machined are 20 microns in width,
The depth is 150 microns and the length is the same as the width of the waveguide element 6. The filter 10 has a thickness of 15 microns and is inserted into the groove 9 by guiding both walls of the groove 9. An adhesive 11 having the same refractive index as the core layer 3 is provided between the filter 10 and the groove 9.
And the filter 10 is bonded and fixed.

The adhesive 11 is a thermosetting type or an ultraviolet curing type, and the main component of the adhesive 11 is an acrylic resin type.
Select and use epoxy resin, silicone resin, etc. The filter 10 and the groove 9 are made of silicone resin 12
Covered by

The silicone resin 12 covering the filter 10 and the groove 9 has a function of protecting the filter 10 and the adhesive 11 fixing the filter 10 from the external environment.

As shown in FIG. 4B, the waveguide 4 is
A laser diode (hereinafter, referred to as LD) 14 and a photodiode (hereinafter, referred to as PD) 15 are fixed on the silicon substrate 1 at the ends of the respective waveguides 4 by soldering. ing.

The LD (14), PD (15) and the electrode 16 on the base 7 are connected by a gold wire 17.
It has a function of supplying electricity to D (14) and PD (15).

As shown in FIG. 4A, light emitted from the LD (14) enters the waveguide 4, and light emitted from the waveguide 4 is received by the PD (15). LD (14) and PD (1
5) The portion is covered with a silicone resin 18 having a refractive index equal to or close to that of the waveguide 4.

The silicone resin 18 covering the LD (14) and PD (15) portions is made of LD (14) or PD (1).
It has the function of improving the optical coupling state between 5) and the waveguide 4 and protecting the LD (14) and PD (15) from the external environment.

A glass block 19 connected to the fiber array 21 is adhered to the upper surface of the end of the waveguide element 6, and the adhesive fixing the waveguide element 6 and the glass block 19 is heat. It is a curable type or an ultraviolet curable type, and the main component of the adhesive is selected from acrylic resin, epoxy resin and the like.

As shown in FIG. 4C, an inclined portion 26 which is inclined by 8 degrees from a plane perpendicular to the longitudinal direction of the waveguide is formed on the distal end surfaces of the waveguide element 6 and the glass block 19. Has a function of being fixed to the contact surface 21f of the fiber array 21 which is formed on the same plane as the inclined portion 26 and is also inclined by 8 degrees from a surface perpendicular to the longitudinal direction of the optical fiber. ing.

[0018]

However, a glass block 19 is adhered to the upper surface of the waveguide element 6, or a silicone resin 18 is covered on the filter 10, the LD (14) and the PD (15). Adhering and fixing the lid 8 on the top has the problem that the number of work steps increases and the manufacturing cost of the module increases.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, protect the filter section, the LD section, and the PD section from the external environment, withstand the external impact of the entire waveguide element, and Another object of the present invention is to provide a hybrid waveguide module having a structure capable of reducing manufacturing costs.

[0020]

According to a first aspect of the present invention, a planar substrate waveguide element is fixed on a base, and a block for connecting an optical fiber is provided on the waveguide element. In the hybrid type waveguide module in which an optical component such as a laser diode or a photodiode is mounted on the waveguide element and the waveguide element and the entire optical component are covered with a lid fixed to the base, Are formed integrally, and the tip surface of the lid on the block side is formed to be inclined at a predetermined angle.

According to a second aspect of the present invention, the inside of the lid is formed in a cavity, and a hole for filling the cavity with a synthetic resin is formed in the lid.

According to a third aspect of the present invention, the inside cavity of the lid is filled with a synthetic resin for protecting the waveguide element and the optical component.

According to a fourth aspect of the present invention, the distal end surface of the lid on the block side is formed by being polished and inclined by 8 degrees from a plane perpendicular to the longitudinal direction of the waveguide.

According to a fifth aspect of the present invention, a fiber array is provided on the optical fiber for contacting the tip end surface of the lid and connecting the optical fiber to the waveguide, and a connecting surface of the optical fiber with the waveguide is provided. The optical fiber is polished together with the contact surface of the fiber array so as to be formed at an angle of 8 degrees from a plane perpendicular to the longitudinal direction of the optical fiber.

According to a sixth aspect of the present invention, the material of the lid is an inorganic material such as glass or silicon.

That is, according to the present invention, the entire waveguide element is covered with a glass lid having a hollow inside, and the inside of the lid is filled with a silicone resin having a refractive index equal to or close to that of the core. Further, the glass lid and the tip of the waveguide element are polished eight times on the same plane.

According to the above configuration, since the block is formed integrally with the lid, the operation of fixing the block to the waveguide element can be omitted. In addition, since the inside of the lid is formed in a cavity, and a hole is formed in the lid, the optical components mounted on the waveguide element are filled with resin from the hole and are collectively sealed with resin. . As a result, the number of working steps is reduced, and the manufacturing cost of the module is reduced.

[0028]

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a hybrid waveguide device according to the present invention.

FIG. 1A is a perspective view of the waveguide element, and FIG.
1B is a side sectional view, and FIG. 1C is a front view.

As shown in FIG. 1A, a hybrid type waveguide device according to the present invention has a waveguide 4 on a base 7.
Is fixed by a thermosetting epoxy resin, and the waveguide element 6 has a rectangular shape.
A glass block 19 for connecting the optical fiber 20 to the waveguide 4 is fixed thereon, and an LD (14), a PD (15), and a dielectric multilayer filter 10 are provided at predetermined positions on the waveguide element 6. Such optical components are mounted.

The waveguide 4 is linearly formed between both ends in the longitudinal direction of the waveguide element 6, and has one end connected to the above-described LD (14) via a bifurcated branch 13. Optically connected, the other end is the PD (1
5) and is optically connected. Furthermore, these LD
(14) and PD (15) so that power is supplied,
Electrode 16 and gold wire 1 formed on base 7 respectively
7 are electrically connected.

This waveguide element 6 has, as shown in FIG.
A lower cladding layer 2 is deposited on a silicon substrate 1, and a core layer 3 is deposited on the lower cladding layer 2. Then, a photolithographic technique and an etching technique are applied to the core layer 3 to form a waveguide, and an upper clad layer 5 is deposited on the formed waveguide.

The dielectric multilayer filter 10 is guided and inserted into both inner walls of the groove 9 formed by cutting out the waveguide of the waveguide element 6.

The dielectric multilayer filter 10 has a thickness of 15
The groove 9 has a width of 20 microns, a depth of 150 microns, and a length equal to the lateral width of the waveguide element 6.

In the gap between the filter 10 and the groove 9, the core layer 3
An adhesive 11 having the same refractive index as that described above is poured, and the filter 10 is bonded and fixed. The adhesive 11 is a thermosetting type or an ultraviolet curing type, and the main component of the adhesive 11 is selected from acrylic resin, epoxy resin, silicone resin and the like.

Further, as shown in FIG. 1 (b), the waveguide element 6 and the optical components 10, 14,
The whole 15 is covered with a lid 22 fixed to the base 7 with an adhesive made of a thermosetting epoxy resin exposing the connection surface 4f of the waveguide shown in FIG. 1C.

The lid 22 is formed of a box-shaped glass having a hollow inside, and the glass block 19 for connecting the optical fiber 20 on the waveguide element 6 is provided on the connection side with the optical fiber 20. Are formed integrally.

A circular hole 24 for injecting a resin is formed at the bottom of the lid 22 so as to cover the optical component, and the same refractive index as that of the core layer 3 is provided inside the lid 22. A silicone resin 23 having a refractive index close to or near that is filled.

The lid 22 is made of an inorganic material such as glass or silicon in order to easily form a cavity inside and a hole 24 at the bottom.

As shown in FIG. 2A, in order to connect the optical fiber 20 to the waveguide of this waveguide element, the optical fiber 20 is provided with a fiber array 21 which is in contact with the block 19 described above. Have been.

Further, as shown in FIG. 2B, the distal end surface 25 of the lid 22 on the block side is formed such that the connection surface of the above-described waveguide is 8 ° away from a surface perpendicular to the longitudinal direction of the waveguide.
The optical fiber 20 is polished together with the waveguide so that the optical fiber 20 is formed at the same plane, and the connecting surface 20f of the optical fiber 20 is also 8 ° from a plane perpendicular to the longitudinal direction of the optical fiber 20. The contact surface 21f of the fiber array 21 is polished together with the optical fiber 20 so that the optical fiber 20 is inclined to the same surface.

The base is provided with a support 7s for supporting the fiber array 21 so that the fiber array 21 can be easily brought into contact with the block 19.

Next, the operation will be described.

In manufacturing the hybrid waveguide module, since the block 19 is formed integrally with the lid 22, the operation of fixing the block 19 to the waveguide element 6 is omitted, and the hole of the lid 22 is formed. The optical components 10, 14, and 15 mounted on the waveguide element 6 are filled with the silicone resin 23 from 24, and are resin-sealed together.

As a result, the number of working steps is reduced, and the manufacturing cost of the module is reduced.

When the optical fiber 20 is connected to the hybrid waveguide module, the fiber array 21 is placed on the supporting portion 7s of the base 7, and the fiber array 21 is supported by the supporting portion 7s to be vertical. Fixed in the horizontal direction and slid in the horizontal direction.
The connection surface 20f inclined at 8 degrees of 0 and the connection surface 4f inclined at 8 degrees of the waveguide 4 are connected and fixed.

By forming the supporting portion 7s on the base 7, the connection of the optical fiber 20 to the waveguide 4 is facilitated, and the connecting surfaces 4f, 20f are formed to be inclined at 8 degrees. Thereby, the transmission loss of light between the waveguide 4 and the optical fiber 40 is reduced.

Next, an experiment was conducted on the reliability of the hybrid waveguide module thus obtained.

In this experiment, a temperature cycle of 40 to 85 ° C. was performed at least 500 times,
The test was performed by examining the deterioration of the characteristics of a sample left for 5 hours in a high-temperature, high-humidity atmosphere of 5% and a humidity of 95%.

As a result, no deterioration of the characteristics was observed in any of the experiments.

[0052]

In summary, according to the present invention, the entire waveguide element is covered with a glass lid having a hollow inside, and the inside of the lid is filled with a silicone resin having a refractive index equal to or close to that of the core. This protects the filter and the adhesive fixing the filter from the external environment, improves the optical coupling state between the LD or PD and the waveguide, and
A function of protecting the LD and PD from the external environment can be provided. Further, the lid has a function of withstanding the entire waveguide element against an external impact.

The end face of the lid is polished eight times together with the tip of the waveguide element, and the tip of the waveguide is flush with the tip of the optical fiber which is also polished eight times. In addition, the transmission loss of light at the connection between the waveguide and the optical fiber can be reduced.

Further, according to the present invention, the number of man-hours for manufacturing is reduced and the manufacturing cost of the module is reduced, so that an industrially useful hybrid type waveguide module can be provided.

[Brief description of the drawings]

1A and 1B show a hybrid waveguide module according to the present invention, wherein FIG. 1A is a perspective view of a waveguide element, FIG. 1B is a side sectional view, and FIG. 1C is a front view.

2A and 2B show the hybrid waveguide module of FIG. 1, wherein FIG. 2A is a top view and FIG. 2B is a side view.

FIG. 3 is an enlarged sectional view of the dielectric multilayer filter of FIG. 1;

4A and 4B show a conventional hybrid waveguide module, wherein FIG. 4A is a perspective view, FIG. 4B is a perspective view of a waveguide element,
(C) is a side sectional view of the waveguide element, (d) is a front view,
(E) is an enlarged sectional view of a dielectric multilayer filter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Silicon substrate 4 Waveguide 4f Connection surface 6 Waveguide element 7 Base 14 Laser diode (LD) 15 Photodiode (PD) 19 Glass block 20 Optical fiber 20f Connection surface 21 Fiber array 21f Contact surface 22 Glass cover 23 Silicone Resin 24 Hole 25 Tip surface

Continued on the front page (72) Inventor Yoshiaki Ishigami 5-1-1, Hidaka-cho, Hitachi City, Ibaraki Prefecture Inside the Opto-System Research Laboratory, Hitachi Cable, Ltd. (72) Inventor Toshikazu Hashimoto 2-3-3, Otemachi, Chiyoda-ku, Tokyo No. 1 Nippon Telegraph and Telephone Corporation (72) Inventor Tsutomu Kuroiwa 216 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture F-term in the Information and Communication Division, Hitachi, Ltd. 2H037 AA01 BA02 BA11 BA24 CA10 DA03 DA04 DA14 DA17 DA36 2H047 KA03 KA12 LA12 MA05 MA07 RA08 TA01 TA32 TA44

Claims (6)

[Claims] 1. A planar substrate waveguide element is fixed on a base, a block for connecting an optical fiber is fixed on the waveguide element, and an optical component such as a laser diode or a photodiode is mounted on the waveguide element. In the hybrid type waveguide module in which the whole of the waveguide element and the optical component are mounted and covered with a lid fixed to the base, a lid integrating the block is formed, and a tip end surface of the lid on the block side is formed. A hybrid waveguide module formed by inclining at a predetermined angle. 2. The hybrid waveguide module according to claim 1, wherein the inside of the lid is formed in a cavity, and a hole is formed in the lid to fill the cavity with a synthetic resin. 3. The hybrid waveguide module according to claim 2, wherein a synthetic resin for protecting the waveguide element and the optical component is filled in an inner cavity of the lid. 4. The hybrid-type waveguide module according to claim 1, wherein the tip surface of the lid on the block side is polished and inclined by 8 degrees from a surface perpendicular to the longitudinal direction of the waveguide. 5. An optical fiber, wherein a fiber array is provided for contacting the tip end surface of the lid and connecting the optical fiber to the waveguide, and the connection surface of the optical fiber with the waveguide is formed in the longitudinal direction of the optical fiber. 2. The hybrid type waveguide module according to claim 1, wherein the module is polished together with the contact surface of the fiber array so as to be formed at an angle of 8 degrees from a plane perpendicular to the fiber. 6. The hybrid waveguide module according to claim 1, wherein a material of the lid is an inorganic material such as glass or silicon.