JPH05264865A - Waveguide device - Google Patents

Abstract

PURPOSE:To provide the waveguide device which is small in size and has excellent connecting performance. CONSTITUTION:Fitting guide grooves 8 and clearance adjusting grooves 18 are formed as separate grooves on the surface of a semiconductor chip 15 formed with an optical waveguide 5 on the surface of a substrate 4. Clearance adjusting pins 17 are housed into the clearance adjusting grooves 18. Second grooves 21 are fitted to the upper side of the clearance adjusting pins 17 and a pin retaining cap plate 7 is applied thereon. The waveguide chip 15, the clearance adjusting pins 17 and the pin retaining cap plate 7 are integrated by adhesion, etc., by which the waveguide device 1 is formed. The size of the pin fitting holes 13 enclosed by the fitting guide grooves 8 and the first grooves 20 on the pin retaining cap plate 7 side is regulated by the diameter of the clearance adjusting pins 17. The attachment, detachment and connection of the waveguide device 1 and optical connectors 3a, 3b are executed by fitting the pin fitting holes 13 to the fitting pins 6 for positioning on the optical connectors 3a, 3b side with zero clearances.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waveguide device that performs optical demultiplexing / multiplexing and optical branching / coupling.

[0002]

2. Description of the Related Art An optical waveguide is formed on a substrate, and mainly,
Waveguide devices that perform optical demultiplexing / multiplexing and optical branching / coupling are widely known.

When connecting the optical waveguide of this waveguide device and the optical fiber of a single-core optical fiber or an optical array in which a plurality of optical fibers are aligned and fixed, the work of aligning and connecting each one by adhesion or welding is very difficult. However, the workability is poor due to the small hand clearance. For this reason, recently, a connection method for connecting the optical waveguide and the optical fiber in an unaligned state has been widely adopted.

FIG. 9 shows an optical connector 3 including a waveguide device 1 and each optical fiber of a tape-shaped multi-core optical fiber core wire 2.
There is shown a connector connection example (a connector connection example which was previously developed by the applicant and has not been publicly known yet) in which a and 3b are used to removably connect without alignment. In the figure, the waveguide device 1 is formed to have a substrate 4 made of silicon or the like, a positioning fitting pin 6, and a pin pressing cover plate 7. One or more optical waveguides 5 are formed on the surface of the substrate 4 to form a waveguide chip 15, and V-shaped fittings are provided on both sides of the chip surface with the optical waveguide 5 forming region sandwiched therebetween. A guide groove 8 is formed, and a trapezoidal groove 10 is formed on the lower surface side of the pin pressing cover plate 7 at a position facing the fitting guide groove 8. A pair of pin fitting holes 13 sandwiched between the fitting guide grooves 8 and 10 are formed extending in the length direction of the optical waveguide 5.
The positioning fitting pin 6 which is longer than the substrate 4 is accommodated therein. Both ends of this positioning mating pin 6 are waveguide chips 15
Of the waveguide device, the waveguide chip 15, the positioning fitting pin 6, and the pin pressing cover plate 7 are integrally fixed by adhesion or the like in this state. 1 is formed. The protruding direction of the fitting pin 6 is parallel to the core axis of the optical waveguide 5 on the core end 9 side.

A multi-core optical fiber core wire 2 is connected and fixed to the optical connectors 3a and 3b connected to the waveguide device 1, and each of the multi-core optical fiber core wires 2 is inside the optical connectors 3a and 3b. The optical fiber is inserted and fixed, and the end of the optical fiber is exposed on the connection end face 11 side of the optical connectors 3a and 3b. The arrangement pitch of the optical fibers exposed on the side of the connection end face 11 is equal to the arrangement pitch of the core end portions 9 of the optical waveguide 5, and the pin insertion holes 12 provided through the optical connectors 3a and 3b are positioned. The optical fibers of the optical connectors 3a and 3b and the respective optical waveguides 5 on the side of the waveguide device 1 are aligned by being fitted into the fitting pins 6, and the optical waveguides on the input side and the output side of the waveguide device 1 are respectively guided. The attachment / detachment of the waveguide 5 and the optical fibers of the optical connectors 3a and 3b is achieved.

[0006]

In this type of waveguideless device 1 and the optical connectors 3a and 3b of non-centering connection method, the connection performance is determined by the accuracy of fitting the positioning fitting pin 6 and the pin insertion hole 12. To be done. Therefore, in order to improve the connection performance, it is necessary to sufficiently improve the mounting dimension accuracy of the positioning fitting pin 6 mounted on the waveguide chip 15. Since the positioning fitting pin 6 is in position regulation by contacting both tapered side surfaces 14 of the fitting guide groove 8 and the bottom surface 16 of the trapezoidal groove 10, pay particular attention to the groove depth of the trapezoidal groove 10. Therefore, it is extremely difficult to perform precision machining with ultra-high precision, and therefore, the manufacturing and assembling of the waveguide device 1 is very difficult, the yield of the product is reduced, the work efficiency of the assembling and manufacturing is poor, and the product cost is low. There was the problem of becoming expensive.

In order to solve such a problem, the applicant has prototyped a waveguide device having a structure shown in FIG. 8 (this device has not been publicly known). In this prototype device, the clearance adjusting pin 17 is housed in the central portion of the V-shaped fitting guide groove 8 provided in the waveguide chip 15.
In this state, the upper side of the clearance adjusting pin 17 is fitted into the groove 10 and the pin pressing cover plate 7 is covered on the upper side of the waveguide chip 15 to bond the waveguide chip 15, the clearance adjusting pin 17 and the pin pressing cover plate 7. And the like to form the waveguide device 1, and the space surrounded by the fitting guide groove 8 and the groove 10 on both ends of the input and output of the waveguide chip 15 is used as the pin fitting hole 13. In this prototype example, the proximal ends of the positioning fitting pins 6 are fitted and fixed in the pin insertion holes 12 of the optical connectors 3a and 3b,
By fitting the protruding tip side of the positioning fitting pin 6 into the pin fitting hole 13, the optical waveguide 5 of the waveguide device 1
And the optical fiber 19 on the side of the optical connectors 3a and 3b are connected / disconnected.

According to this prototype device, even if the processing accuracy of the fitting guide groove 8 on the waveguide chip 15 side and the groove 10 on the pin pressing cover plate 7 side is lowered, the size of the pin fitting hole 13, that is, The diameter of the circle inscribed in the tapered side surface 14 of the fitting guide groove 8 and the bottom surface 16 of the groove 10 can be easily adjusted to match the diameter of the positioning fitting pin 6 by changing the diameter of the clearance adjusting pin 17. The waveguide device 1 can be adjusted, and the manufacturing and assembling of the waveguide device 1 can be facilitated, the connection performance with the optical connectors 3a and 3b can be improved, and the manufacturing cost of the waveguide device 1 can be reduced. is there.

However, since the prototype waveguide device accommodates the clearance adjusting pin 17 in the central portion of the fitting guide groove 8 of the waveguide chip 15, the portions of the fitting guide groove 8 on both sides of the clearance adjusting pin 17 are accommodated. Optical connector 3
It is necessary to secure a groove length for accommodating the positioning fitting pins 6 of a and 3b. Therefore, as the groove length of the fitting guide groove 8, the length of the clearance adjusting pin 17 and the optical connector 3 are set.
There is a problem that the total length of the protruding lengths of the positioning fitting pins 6 on the a and 3b sides is the minimum required, and the length dimension of the waveguide chip 15 is inevitably large, and the waveguide device becomes large. was there. Of course, clearance adjustment pin 17
The waveguide device can be miniaturized by shortening the length of the positioning fitting pin 6 and shortening the protruding length of the positioning fitting pin 6, but by shortening the clearance adjustment pin 17, the stability of the joining between the waveguide chip 15 and the pin retainer cover plate 7 is improved. And the accuracy of the pin fitting hole 13 decreases, and if the protrusion length of the positioning fitting pin 6 is shortened, the stability of the connection of the optical connectors 3a and 3b becomes poor and the optical waveguide. 5 and each optical connector 3a, 3b
There is a problem that the connection loss with the optical fiber 19 becomes large.

The present invention has been made to solve the above problems, and an object thereof is to make it possible to miniaturize a waveguide device and to provide an optical waveguide of the waveguide device and an optical fiber of an optical connector. An object of the present invention is to provide a waveguide device with good performance that can reduce connection loss.

[0011]

In order to achieve the above object, the present invention is configured as follows. That is, according to the present invention, a clearance adjustment groove and a taper side surface whose wall spacing is narrower toward the bottom are provided on both sides of the waveguide chip formed by forming the optical waveguide on the substrate with the optical waveguide interposed therebetween. Two or more fitting guide grooves extending in the lengthwise direction of the optical waveguide are provided, and a clearance adjusting pin is accommodated in the clearance adjusting groove. The clearance adjusting pin is provided on the waveguide chip and the upper side thereof. The pin holding cover plate is pinched and the space hole formed between the fitting guide groove and the pin holding cover plate is a pin fitting hole. Is regulated by the diameter of the clearance adjusting pin.

[0012]

In the present invention having the above structure, the size of the pin fitting hole is adjusted by varying the diameter of the clearance adjusting pin when assembling the waveguide device. Then, the positioning fitting pin on the optical connector side is fitted into the adjusted pin fitting hole with zero clearance, so that the optical waveguide of the waveguide device and the optical fiber of the optical connector are aligned and connected / disconnected. Is achieved.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. In the embodiments described below, the same parts as those of the above-mentioned developed and prototype waveguide devices are designated by the same reference numerals, and the duplicated description will be omitted. 1 and 2 show a first embodiment of a waveguide device according to the present invention.
In this embodiment, the optical connectors 3a,
A positioning fitting pin 6 is provided on the 3b side, and the waveguide chip 15 is formed by forming an optical waveguide 5 on the surface of a substrate 4 such as silicon. This embodiment is different from the above-mentioned prototype in that a V-shaped fitting guide groove 8 is formed on the surface side of the waveguide chip 15 by sandwiching the optical waveguide 5 on both sides thereof by grinding or etching. Further, a pair of V-shaped clearance adjusting grooves 18 are similarly provided on both sides of the pair of fitting guide grooves 8 along the fitting guide groove 8, and the fitting guide is provided on the pin pressing cover plate 7 side. That is, the trapezoidal first groove 20 facing the groove 8 and the trapezoidal second groove 21 facing the clearance adjusting groove 18 are formed. The fitting guide groove 8 is parallel to the core axis on the input / output end side of the optical waveguide, as in the prototype.

The fitting guide groove 8 is provided in the optical connector 3a,
When the positioning fitting pin 6 on the 3b side is fitted in contact with the tapered side surface 14, the connection end faces of the optical connectors 3a and 3b
Optical fiber of multi-core optical fiber core 2 exposed on side 11
The groove size 19 is formed so that the height thereof coincides with the core end portion 9 of the optical waveguide 5 on the waveguide chip 15 side. On the other hand, the size of the clearance adjusting groove 18 is not particularly limited, but in this embodiment, the clearance adjusting groove 18 has the same size and shape so that it can be processed in the same process as the fitting guide groove 8.

A cylindrical clearance adjusting pin 17 is accommodated in the clearance adjusting groove 18 over substantially the entire length thereof in contact with the tapered side surface of the groove 18. With the clearance adjusting pin 17 accommodated in the clearance adjusting groove 18, the pin pressing cover plate 7 is covered on the upper side of the waveguide chip 15, and the upper end side of the clearance adjusting pin 17 is the groove of the trapezoidal second groove 21. The clearance adjusting pin 17 is in contact with the bottom surface and is sandwiched between the waveguide chip 15 and the pin pressing cover plate 7 to be integrated by adhesion or the like. The fitting guide groove 8 is covered with the pin pressing cover plate 7, and is surrounded by the tapered side surface 14 and the wall surface of the first groove 20 to form a pin fitting hole 13. The diameter of the circle inscribed in the tapered side surface 14 and the bottom surface 20a of the first groove 20 in the pin fitting hole 13 is regulated by the diameter of the clearance adjusting pin 17, and the inscribed circle of the fitting guide groove 8 is The diameter of the clearance adjustment pin is equal to or slightly smaller than the diameter of the positioning fitting pin 6.
The diameter of the clearance adjusting pin 17 is selected so that the diameter of the inscribed circle of the fitting guide groove 8 is 0.699 mm, and the diameter of the positioning fitting pin 6 is 0.7 mm. The pore diameter is made smaller by 1 μm.

When the waveguide device 1 of this embodiment is connected to the optical connectors 3a and 3b, the optical connectors 3a and 3b are used.
This is performed by inserting the positioning fitting pin 6 on the b side into the pin fitting hole 13 on the side of the waveguide device 1. Before the positioning fitting pin 6 is inserted into the pin fitting hole 13, As shown in (a), the waveguide device 1 and the pin pressing cover plate 7 are in a state before elastic deformation. On the other hand, when the positioning fitting pin 6 of the optical connectors 3a and 3b is fitted into the pin fitting hole 13, the diameter of the inscribed circle of the pin fitting hole 13 is equal to that of the positioning fitting pin 6 as described above. Since the diameter is slightly smaller than the diameter, the waveguide chip 15 and the pin pressing cover plate 7 are slightly elastically deformed in the vertical direction with the adhesive fixing portion 27 of the clearance adjusting pin 17 serving as a fulcrum, and the pin fitting hole 13 is expanded. As a result, due to the restoring force of this elastic deformation, the positioning fitting pin 6 is fitted in a pressure contact state, whereby a zero clearance connection between the positioning fitting pin 6 and the pin fitting hole 13 is achieved, and the connection loss A small connector connection is possible.

Further, in this embodiment, two types of the fitting guide groove 8 into which the positioning fitting pin 6 is fitted and the clearance adjusting groove 18 into which the clearance adjusting pin 17 is fitted are provided as separate and independent grooves. As compared with the case where the positioning fitting pin 6 and the clearance adjusting pin 17 are housed in one type of groove as in the prototype example, the length of the groove can be sufficiently shortened, and thus the waveguide device 1 Miniaturization is possible.

Even if the waveguide device 1 is made small,
Since the groove length of the accommodating portions of the positioning fitting pin 6 and the clearance adjusting pin 17 can be ensured to be a necessary and sufficient length, the dimensional shape of the pin fitting hole 13 is stable and fits into the pin fitting hole 13. The positioning mating pin 6 is also in a stable mating state,
As a result, the positional deviation between the optical waveguide 5 of the waveguide device 1 and the optical fibers 19 of the optical connectors 3a and 3b and the variation in the positional deviation become very small, and low-loss connection is possible.

In order to confirm this effect, the shape of the core end portion 9 of the optical waveguide 5 is 8 μm square, the relative refractive index difference between the core and the cladding of the optical waveguide 5 is 0.3%, and the optical waveguide 5 is a single mode fiber. When the connection loss between the optical waveguide 5 and the optical fibers of the optical connectors 3a and 3b and the reproducibility in attachment / detachment were measured with a single mode fiber attached to the optical connectors 3a and 3b side, It was confirmed that the loss could be connected with an average of 0.5 dB, and the reproducibility of attachment and detachment was 0 in the prototype example.
The value of 2 to 0.3 dB was 0.2 dB or less in this example, and excellent reproducibility could be obtained.

FIG. 4 shows a second embodiment of the present invention. In this embodiment, the clearance adjusting groove 18 formed in the waveguide chip 15 has a U-shaped groove with a flat bottom at the upper end, and the fitting guide groove 8 has a flat bottom at the bottom. The groove is an inverted trapezoidal shape, the groove is not formed on the pin pressing cover plate 7 side, and the surface facing the waveguide chip 15 is a flat surface. The other configurations are the same as those of the first embodiment. It is the same. Also in this embodiment, the clearance between the fitting guide groove 8 and the pin pressing lid plate 7, that is, depending on the diameter of the clearance adjusting pin 17 accommodated in the clearance adjusting groove 18,
The diameter of the inscribed circle contacting the tapered side surface 14 of the fitting guide groove 8 and the bottom surface of the pin pressing cover plate 7, in other words, the size of the pin fitting hole 13 can be variably adjusted, and the optical connectors 3a and 3b can be adjusted.
The zero clearance fitting with the positioning fitting pin 6 is achieved, and low loss connector connection is possible.

Also in this embodiment, since the fitting guide groove 8 into which the positioning fitting pin 6 is fitted and the clearance adjusting groove 18 into which the clearance adjusting pin 17 is fitted are separate grooves, the waveguide device 1 can be miniaturized. It is possible to achieve the same effects as those of the first embodiment, such as the achievement.

FIG. 5 shows a third embodiment of the present invention. In this embodiment, the second groove 21 on the pin pressing cover plate 7 side for accommodating the clearance adjusting pin 17 is a V-shaped groove similar to the clearance adjusting groove 18 on the waveguide chip 15 side, and the waveguide chip 15 The clearance adjusting pin 17 is housed in the clearance adjusting groove 18, and the pin pressing cover plate 7 is easily positioned during assembly when the pin pressing cover plate 7 is placed on it. The bottom surface of the fitting guide groove 8 on the waveguide chip 15 side is formed into a rounded shape, and the waveguide chip 15 and the pin pressing cover plate 7 are not fixed with an adhesive or the like, and metal or plastic is used. The waveguide chip 15 and the pin pressing cover plate 7 are clamped and integrated by a clamp member 22 having spring elasticity such as. The other structure is the same as that of the first embodiment. In this embodiment, since the waveguide chip 15 and the pin pressing cover plate 7 are elastically deformed in the pressure contact direction by the clamping force of the clamp member 22, the diameter of the clearance adjusting pin 17 is not necessarily the same as the diameter of the positioning fitting pin. It need not be below and may be slightly larger than the diameter of the locating mating pin 6.

In this embodiment, since the bottom surface of the clearance adjusting groove 18 has a rounded shape, stress concentration generated when the groove is a V-shaped sharp groove is suppressed, and silicon or the like is used as the material of the substrate 4. Even when a brittle substrate is used, it is possible to prevent the occurrence of damage due to the stress concentration. In addition, in addition to the first
It is possible to obtain the same effect as that of the embodiment.

FIG. 6 shows a fourth embodiment of the present invention. In this embodiment, a plurality of waveguide devices 1 having different patterns of optical waveguides 5, two in this figure, are connected and fixed, and optical connectors 3a,
3b is detachably connected. In this way, by connecting a plurality of waveguide devices 1 of different waveguides, various signal processing can be developed.

FIG. 7 shows a fifth embodiment of the present invention. In this embodiment, as in the above embodiments, after the waveguide device 1 is assembled, the waveguide device 1 is attached to the core end portion 9 of the optical waveguide 5 and the pin fitting hole on the input / output end side.
13 is left and the remaining part is molded with a synthetic resin such as epoxy. As described above, by molding the waveguide device 1, it is possible to form irregularities such as the engaging portion 23 and the engaging hole 24 on the outer surface of the molding resin, and the engaging portion 23 and the like have spring elasticity. Spring clamp 25
The leg 25a of the spring clamp 25 is engaged with the leg 25a of the
The waveguide device 1 by locking b to the rear end face 26 of the optical connector
The connection state between the optical connector 3a and the optical connector 3b can be held by the elastic restoring force of the spring clamp 25. Further, since the molding resin functions as a reinforcing agent, the waveguide chip 15, the clearance adjusting pin 17, and the pin pressing cover plate 7 are provided.
It is possible to increase the strength of bonding and fixing with and to increase the mechanical strength against external force.

The present invention is not limited to the above-mentioned embodiment, and various embodiments can be adopted. For example, although a plurality of optical waveguides 5 are formed on the waveguide chip 15 in each of the above-described embodiments, the number of the optical waveguides 5 can be any number of 1 or more. The optical fiber cores on the side of the optical connectors 3a and 3b do not necessarily have to be multicore, and may be single core.

[0027]

As described above, according to the present invention, the size of the pin fitting hole is restricted by the diameter of the clearance adjusting pin, so that the fitting guide groove and the fitting guide groove are opposed to each other. Even if the processing accuracy of the groove on the pin retainer cover plate side is moderate, the accuracy of the pin fitting hole can be improved sufficiently by simply inserting the clearance adjustment pin into the clearance adjustment groove and then assembling. The zero clearance connection between the side positioning fitting pin and the pin fitting hole can be ensured, and the connection performance can be significantly improved. Further, since super-precision groove processing is not required, the manufacture of the waveguide device becomes very easy, the yield rate of the product can be increased, and the waveguide device with good connection performance can be provided at low cost. it can.

Further, since the clearance adjusting groove for accommodating the clearance adjusting pin and the fitting guide groove for fitting the positioning fitting pin on the optical connector side are formed as separate and independent grooves on the waveguide chip, this positioning is performed. The waveguide device can be sufficiently miniaturized as compared with the prototype example in which the fitting pin and the clearance adjusting pin are housed in the same fitting guide groove. Moreover, since the fitting length of the positioning fitting pin and the clearance adjusting pin can be sufficiently secured and stable fitting can be achieved, the dimension and shape of the pin fitting hole can be stabilized and the positioning on the optical connector side can be achieved. Since the fitting pins can be fitted in a stable state, it is possible to obtain a low loss connection between the optical connector and the waveguide device and a good reproducibility of attachment / detachment under the low loss connection.

[Brief description of drawings]

FIG. 1 is a perspective configuration diagram showing a first embodiment of a waveguide device according to the present invention.

FIG. 2 is an exploded perspective view of the waveguide device of the same embodiment.

FIG. 3 is an explanatory diagram showing elastically deformed states of the waveguide device of the same example before and after connection with a connector.

FIG. 4 is a configuration explanatory diagram of a second embodiment of the present invention.

FIG. 5 is a structural explanatory view showing a third embodiment of the present invention.

FIG. 6 is a structural explanatory view showing a fourth embodiment of the present invention.

FIG. 7 is a structural explanatory view showing a fifth embodiment of the present invention.

FIG. 8 is an explanatory diagram of a configuration of a waveguide device which the applicant previously made a trial.

FIG. 9 is a perspective illustration of a waveguide device previously developed by the applicant.

[Explanation of symbols]

 1 waveguide device 2 multi-core optical fiber core wire 3a, 3b optical connector 6 positioning mating pin 7 pin retainer cover plate 8 mating guide groove 13 pin mating hole 15 waveguide chip 17 clearance adjusting pin 18 clearance adjusting groove 20 First groove 21 second groove

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Shiro Nakamura 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd.

Claims (1)

[Claims] 1. A fit which has a clearance adjusting groove and tapered side surfaces whose wall intervals are narrower toward the bottom on the surfaces of both sides of the optical waveguide of a waveguide chip formed by forming an optical waveguide on a substrate. Two or more coupling guide grooves are provided so as to extend in the length direction of the optical waveguide, and a clearance adjusting pin is accommodated in the clearance adjusting groove. The clearance adjusting pin is attached to the waveguide chip and the upper side thereof. The pin holding cover plate is sandwiched between the fitting guide groove and the pin holding cover plate, and the space hole formed between the fitting guide groove and the pin holding cover plate is a pin fitting hole. A waveguide device regulated by the diameter of the clearance adjustment pin.