JPH059685Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a connection device that can easily connect an optical fiber and a flat optical waveguide with high precision.

[Description of Prior Art] Conventionally, when connecting a planar waveguide and an optical fiber, as shown in FIG. A method is used in which the parts are fixed with adhesive 3.

To align the optical axes of optical fiber 2 and waveguide 1,
Set both on the precision fine adjustment device, enter the light, and while operating the feed of the fine adjustment device, find the position where the amount of output light is maximum, and fix both 1 and 2 with adhesive at the position where the amount of light is maximum. ing.

In addition, as shown in Fig. 8, as a method for improving the workability of optical axis alignment, the optical fiber 2 to be connected to the waveguide is integrated by sandwiching it between plates 4 made of glass, ceramics, etc., and the end face of this composite is used to guide the optical fiber. A method of adhering and fixing by abutting against the end face of the wave path has also been adopted.

[Problems to be solved by the invention] In the conventional connecting structure described above, the optical axis can easily shift due to the viscosity of the connecting agent until the adhesive is completely cured, and especially when the adhesive hardens, The contraction force causes the fiber to become misaligned.

Further, even after the adhesive has hardened, the bond often comes off due to a slight impact on the fiber portion, which poses a problem in terms of bond strength.

Furthermore, the optical fiber and the waveguide must be individually clamped to fine movement devices to adjust the x, y, and z directions and the tilt angle in each direction.
This method has the disadvantage that it takes a lot of effort to align the optical axis.

Furthermore, in the conventional method, when the clamp of the fine movement device is removed after adhesion, the gripping force of the clamp becomes residual stress and causes distortion in the optical fiber, which tends to cause performance deterioration over time or due to the environment.

[Means for solving the problems] The connection device of the present invention that solves the above problems has the following features:
An optical fiber receiving groove 14 and a pair of waveguide positioning pin receiving grooves 15 are formed in the base plate 10 with this groove sandwiched therebetween, and a waveguide substrate 12 is connected to the optical fiber.
A similar pin receiving groove 16 is provided in correspondence with the pin receiving groove of the base plate, and the base plate 10 and the waveguide substrate 12 are connected so that the openings of the pin receiving grooves 15 and 16 of both are aligned and a common pin receiving groove is formed between these two grooves. This structure has a structure in which the optical fiber connected to the waveguide is fixed in the fiber receiving groove on the base plate by inserting a pin 17 to determine the connection position.

[Operations/Effects] According to the above structure, by cutting the base plate and the waveguide substrate with high precision in advance, all that is left is to simply insert the pin between the grooves and insert the predetermined optical fiber into the fiber groove. High-precision optical axis alignment can be performed automatically by simply fixing the optical cable, and connections can be easily made at the location where the optical cable is installed without the need for special equipment.

In addition, the optical fiber and waveguide can be reliably held on the base plate in a predetermined positional relationship until the adhesive for final fixing is completely cured, and the fiber can be held securely on the base plate even after the adhesive has cured. Since the waveguide and waveguide are fixed on a common base plate, a connection with high mechanical strength, reliability, and durability can be achieved. moreover,
The predetermined grooving process on the base plate and the waveguide can be easily mass-produced using well-known processing techniques such as wet etching, dry etching, and grooving using a dicing machine.

Further, according to the present invention, even when the end face of an optical fiber is cut diagonally and connected to a waveguide, which has been difficult in the past, it is possible to easily perform a highly accurate and reliable connection.

[Embodiments] The present invention will be described in detail below based on embodiments shown in the drawings.

FIG. 1 is a perspective view of the connecting device of the present invention, FIG. 2 is a front view thereof, and FIG. 3 is a side view thereof. In the figure, reference numeral 10 denotes a base plate made of a rigid plate with a flat surface such as glass or ceramics. An optical fiber 11 and a waveguide substrate 12 are placed on this base plate 10, and the end face of the fiber 11 is formed in the substrate 12. Both 11 and 12 are positioned with respect to the base plate 10 by the structure described below in a predetermined positional relationship in which they are brought into contact with or in close proximity to the input and output end faces of the waveguide 13. A groove 1 for receiving the optical fiber 11 is located approximately at the center of the base plate 10 in the width direction.
4 are formed at a constant depth over the entire length of the base plate 10, and a pair of positioning pin receiving grooves 15 are formed at a constant interval on both sides with the fiber receiving groove 14 in between, extending over the entire length of the base plate 10. It is formed at a constant depth throughout.

On the other hand, a pair of pin receiving grooves 16 are formed on the side surface of the waveguide substrate 12 fixed to the base plate 10, on which the waveguide 13 is formed, with the same groove width and the same spacing as the grooves 15 on the base plate 10.

Then, the waveguide forming surface of the waveguide substrate 12 is placed on the base plate 1.
The openings of the pin receiving grooves 15 and 16 of both pins 10 and 12 are aligned, and the common positioning pin 17 extending between these grooves 15 and 16 is placed at one end. It is inserted from the side to connect both 10 and 12 and to position them relative to each other. The width of the pin 17 is approximately the same as the width of the pin receiving grooves 15 and 16 provided in the base plate 10 and the waveguide substrate 12.
5 and 16, the waveguide substrate 12 is connected to the base plate 1.
Since movement in the width direction and longitudinal direction with respect to 0 is prevented, and movement in the normal direction of the bed plate is prevented by contact with the surface of the bed plate 10, positioning in the x, y, and z directions is achieved. In this state, the base plate 10 and the waveguide substrate 12 are bonded together with an adhesive.

In addition, the fiber receiving groove 14 and the pin receiving groove 15
The relative positional relationship with the pin 17 between the grooves 15 and 16 is
The optical fiber 1 is inserted into the fiber receiving groove 14 with the base plate 10 and the waveguide substrate 12 connected.
When set to 1, the waveguide 13 and the optical fiber 11
It is set in advance so that both optical axes of the two coincide with each other. Then, the waveguide substrate 12 is attached to the base plate 10 as described above.
If the optical fiber 11 is inserted into the fiber receiving groove 14 of the rear bed plate 10 and fixed to the bed plate 10 with adhesive, the optical fiber and the waveguide 13 will be securely connected with their optical axes aligned, and the tilt adjustment can be performed. is also unnecessary. As an example, the cross-sectional diameter of the waveguide 13 is
When the core diameter of the fiber 11 is 50 μmΦ and the outer diameter is 125 μmΦ, the width of the fiber receiving groove 14 is 122.5 μm and the depth is 37.5 μm.

In addition, the cross-sectional size of the positioning pin receiving grooves 15 and 16 varies depending on the size of the board, but generally
Machining precision of about 200 to 500 μm is good and reproducibility is good. The cross-sectional shape of the positioning pin 17 may be circular as shown in FIG. 6a, or it may be rectangular with a height approximately twice the width as shown in FIG. 6b, and the shape may be arbitrary. That's fine. Further, the material of the positioning pin 17 is not particularly limited, but it may be made of a material that has some elasticity, such as a synthetic resin material, and may be press-fitted into the groove with a width slightly larger than the groove width. .

FIG. 4 shows another embodiment of the present invention.

In this example, the incidence of branch waveguides of 1:n (n≧2),
A connecting device is shown for connecting the optical fibers 11 to each output end. One end of the base plate 10 is provided with one groove 14A for receiving the input optical fiber 11A, and the opposite side of the base plate 10 is provided with a groove 14A for receiving the input optical fiber 11A. Output fibers 11B are installed in parallel at intervals and numbers that match the waveguide.
A group of receiving grooves 14B are provided, and the other structure is the same as that shown in FIGS. 1 to 3.
FIG. 5 shows an example in which the present invention is applied to a connection between a demultiplexer waveguide and an optical fiber. The waveguide 13 has a V-shape in which a pair of straight branch paths meet at the side edge of the substrate at a constant inclination angle θ, and the bottom of the V-shape is exposed at the side edge of the substrate. An interference film is provided that transmits light of one wavelength and reflects light of other wavelengths, and by inputting mixed light of two wavelengths λ1 and λ2 through an optical fiber 11A connected to one branch path,
Light of wavelength λ1 is taken out from the optical fiber 11B connected to the output end where the interference film is installed, and light of wavelength λ2 is taken out through the optical fiber 11C connected to the other branch path.

The connection device between the branching waveguide and the optical fiber described above can also be achieved by forming the fiber receiving groove 14 on the base plate 10 by tilting it at a predetermined angle θ in plan view.
The fiber and waveguide can be aligned easily and with high precision.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing one embodiment of the present invention;
3 is a side view of the same, FIG. 4 is a plan view showing another embodiment of the present invention, FIG. 5 is a plan view showing still another embodiment of the present invention, and FIG. are a, b
7 is a front view showing an example of the cross-sectional shape of the positioning pin of the connecting device of the present invention, and FIGS. 7 and 8 are side sectional views showing a conventional connection structure between an optical fiber and a waveguide. 10... Base plate, 11, 11A, 11B, 11C
...Optical fiber, 12...Waveguide substrate, 13...
Waveguide, 14...Fiber receiving groove, 15, 16
... Locating pin receiving groove, 17... Locating pin.

Claims (1)

[Scope of utility model registration request] The base plate 10 is formed with an optical fiber receiving groove 14 and a pair of positioning pin receiving grooves 15 sandwiching this groove, and the waveguide substrate 12 connected to the optical fiber is made to correspond to the pin receiving grooves of the base plate. The base plate 10 and the waveguide substrate 12 are positioned by aligning the openings of their pin receiving grooves 15 and 16 and inserting a common pin 17 between these grooves. 1. A connecting device for an optical fiber and a waveguide, characterized in that an optical fiber to be connected to the waveguide is fixed in an upper fiber receiving groove.