JPS60202408A - Optical circuit device - Google Patents

Abstract

PURPOSE:To obtain an optical circuit device having stable photocoupling efficiency by fixing a semiconductor laser on the 1st holding part of a supporting base body, fixing at least one piezo-electric substrate forming an electrode on the 2nd holding part of the supporting base body and fixing an optical circuit substrate on a position where an optical guide is photocoupled with the semiconductor laser on the piezo-electric substrate. CONSTITUTION:Voltage is applied to the piezo-electric substrate 31 and the thickness of the substrate 31 is increased or decreased to maximize the photocoupling between the optical waveguide 15 and the semiconductor laser 14. Since the slight vertical shift changes the photocoupling efficiency sharply, the vertical shift is adjusted by applying the voltage to the substrate 31 and increasing or decreasing the thickness of the substrate 31. For instance, an approximately vertical polarization direction is formed on the 1st plate 41 of the substrate 31 which is the fixing surface of the 2nd holding part 13 and an electrode 43 is formed on the 1st plate 41 and the 2nd plate 42 of the substrate 31 which is approximately parallel with the 1st plate 41. In this case, stainless is for the 2nd holding part 13, the electrode is formed by vapor-deposited aluminium on piezo-electric ceramics and polarized and a Ti diffusion type LiNbO3 optical waveguide having 2mum thickness and sum width is used.

Description

[Detailed description of the invention] Industrial applications The present invention relates to an optical circuit device in the field of optical transmission.

The present invention particularly relates to an optical circuit device using an optical integrated circuit.

Conventional configuration and its problems When integrating and fixing a conventional optical integrated circuit with a semiconductor laser,
The configuration shown in Figure 1 was used. That is, holding base 1
A semiconductor laser 14 is fixed to the first holding part 12 of the holding base 11, and an optical circuit board 16 having a thickness of 3--thin is provided to the second holding part 13 of the holding base 11, to which the semiconductor laser 14 and the optical waveguide 16 are optically coupled. was. However, due to variations in the thickness of the adhesive, sufficient optical coupling could not be obtained when the thickness of the optical waveguide was less than 1 mm.

In order to improve this point, the structure shown in FIG. 2 was proposed. In the same figure, 11, 12, 13, 14° 15.16
is the same as in Figure 1. Figures & and b are a front view and a sectional view of the main part, respectively.

In the figure, in order to increase the optical coupling efficiency, a tapered support 21 is inserted between the optical circuit board 16 and the second holding part 13 to maximize the optical coupling efficiency, and the structure is fixed with an adhesive 22. This structure has a problem in that the adhesive 22 shrinks and solidifies when it is fixed, causing positional displacement and reducing optical coupling efficiency. In actual manufacturing, the optical coupling position was moved from the beginning in consideration of the amount of shrinkage, so that the maximum optical coupling efficiency was achieved when the adhesive 22 solidified. However, since the situation varies depending on the amount of adhesive, humidity, temperature, and surface condition, the maximum optical coupling cannot always be obtained, and there is a problem in that the optical coupling efficiency varies greatly.

In addition, it also has the disadvantage that the optical coupling efficiency fluctuates due to differences in the expansion coefficients of various parts due to fluctuations in outside temperature.

The present inventors have improved the drawbacks of the conventional configuration by using a new optical circuit board holding configuration. The present invention provides a structure of an optical circuit device that prevents fluctuations in optical coupling efficiency due to temperature changes and has stable optical coupling efficiency.

Structure of the Invention An optical circuit device according to the present invention includes an optical circuit board provided with at least a semiconductor laser and an optical waveguide, and a support base, the semiconductor laser is fixed to a first holding part of the support base, and the semiconductor laser is fixed to a first holding part of the support base, At least one piezoelectric substrate provided with an electrode is fixed to a second holding part of the at least one piezoelectric substrate, and the optical circuit board is fixed on the piezoelectric substrate at a position where the optical waveguide and the semiconductor laser are optically coupled. There is.

DESCRIPTION OF EMBODIMENTS 5-''-? The present invention will be described below using examples. FIG. 3 is a sectional view of a main part according to an example of the present invention.

In the figure, 11, 12, 13, 14, 15°16 are the same as in FIG. That is, it consists of an optical circuit board 16 provided with at least a semiconductor laser 14 and an optical waveguide 15, and a support base 11. A structure according to the present invention in which at least one piezoelectric substrate 31 provided with electrodes is fixed, and an optical circuit board 16 is fixed on the piezoelectric substrate 31 at a position where the optical waveguide 15 and the semiconductor laser 14 are optically coupled. In , it was possible to maximize the optical coupling between the optical waveguide 15 and the semiconductor laser 14 by applying a voltage to the piezoelectric substrate 31 and increasing or decreasing the thickness of the piezoelectric substrate 31 . That is, the cross-sectional structure of the optical waveguide is normally the same as that of the optical circuit board 16.
Since it has a rectangular structure that is long in the in-plane direction of the surface and short in the direction perpendicular to it, the optical coupling efficiency changes greatly due to a slight deviation in the vertical direction. For this reason, when the 6-- structure according to the present invention is used, the number of piezoelectric substrates 31 is increased or decreased to compensate for the vertical deviation by applying a voltage to the piezoelectric substrates 31.

The configuration according to the present invention will be specifically described with reference to FIG.

That is, in the same figure, 11.12, 13°14, . 1
5, 16.31 are the same as in FIG.

In the figure, 1 has a polarization direction substantially perpendicular to the first plane 41 of the piezoelectric substrate 31 that is the fixed surface with the second holding part 13;
Piezoelectric substrate 31 substantially parallel to the 1,000th plane 41 and the first plane 41
An electrode 43 is provided on the 2,000th surface 42 of the substrate. in this case,
The second holding part 13 is made of stainless steel and is made of ABO3-PbTtO3-PbZ rO3-based piezoelectric ceramic with perovskite structure (piezoelectric constant d33-575X1σ12m2Δ)
After electrodes were provided with vapor-deposited aluminum and subjected to polarization treatment, a Ti-diffused LiNb0a optical waveguide with a thickness of 2 μm and a width of 3 μm was used. In this case, the piezoelectric substrate 31 has a thickness of 1
When a predetermined voltage was applied between 01 m and a DC voltage of -100 to +1 oov, the optical coupling efficiency, which was initially eo%, was improved to 70%, confirming the effect of the present invention. In this case, the amount of vertical movement of the optical waveguide based on the thickness of the piezoelectric substrate 31 is only about 150 to 50 nm, but it has a surprisingly large effect on the optical coupling efficiency. It was found that the effects of the present invention are surprisingly large.

Moreover, by further improving the configuration of the present invention, it was possible to improve the optical coupling efficiency. That is, the structure of the example shown in FIG. 6 was good.

In the same figure, 11.12,13,14,15°16.
31.41.42 are the same as in FIG.

In the figure, the 3,000th plane 61 of the piezoelectric substrate 31 having a polarization direction substantially parallel to the first plane 41 and substantially perpendicular to the first plane 41, and the 3,000th plane 61 of the piezoelectric substrate 31 substantially parallel to the 3,000th plane 51. Fourth
If the structure is such that the electrode 53 is provided on the 1,000-sided surface 62, it is possible to improve the optical coupling efficiency even when the efficiency is low.
i-diffusion type LlNbo3 optical waveguide and length 41,101m
Thickness '%V1.

1M piezoelectric ceramic (piezoelectric constant d31=-263X1
0m/V), for example, an optical coupling efficiency of only 6 degrees becomes 8 when a DC voltage of -100 to 10 degrees is applied.
It was confirmed that the improvement was over 0%. In this configuration, it is considered that such an improvement was possible because the number 11 can be increased or decreased by about -0.3 to 0.3 μm.

Furthermore, as a result of a detailed study of this configuration, the present inventors discovered a structure that provides significant effects, and invented a new optical circuit device. This embodiment will be explained based on FIG. In the same figure, 11, 12° 13.15.16 is the third
In other words, two piezoelectric substrates 61 having a polarization direction substantially perpendicular to the surface of the second holding part 13 and having polarization directions different by 180° are bonded together, and the piezoelectric substrates are substantially parallel to the bonding surface. An electrode 63 is provided on the surface 62, and the semiconductor laser 1
4, the first end 64 of the piezoelectric substrate 61 that is farther away from the semiconductor laser 14 is fixed to the second holding part 13, and the piezoelectric substrate 61 that is closer to the semiconductor laser 14
The optical circuit board 16 was fixed to the second end 66 of the. In the above configuration, the piezoelectric substrate 61 has a thickness of 0.3M11. length 16
PLZT with a thickness of 0.5 μm and a width of 3 μm formed on the substrate.
When optically coupled with a system thin film optical thin film optical waveguide body laser,
Since the film thickness is as thin as 0.5 μm, strict positional accuracy is important for optical coupling efficiency. In this case, the optical coupling efficiency is 10
%, but by keeping the DC voltage at a predetermined value in the range of -100 to 100 V, a light coupling efficiency of 50% was obtained. This is a value □ that is close to the ideal value considering the light intensity distribution. Furthermore, it was confirmed that the maximum coupling efficiency can be obtained by changing the voltage even when the optical coupling efficiency fluctuates due to temperature changes. In the embodiment described in FIG.
is directly fixed to the second holding part 13, but the piezoelectric substrate 31
The first plane only needs to be fixed on the second holding part 13, and the seventh plane is fixed on the second holding part 13.
The structure shown in the figure is also included in the present invention. That is, the first plane 41 is fixed to the second holding base 71, and the second holding base 71 is vertically adjusted and fixed by the tapered support 72. A configuration similar to the embodiment shown in FIG. 5 is also possible, and the configuration shown in FIG.
Fgu・7 Included in the present invention. That is, the first plane 41
is fixed to a second holding base 71, and the second holding base 71 is adjusted and fixed in the vertical direction by a tapered support 72. In the structure shown in Fig. 7.8, the vertical adjustment is performed by the tapered support 7.
2, the piezoelectric substrate 31. The optical circuit board 16 does not require strict dimensional accuracy and is easy to manufacture, and the optical coupling efficiency can be adjusted over a wide range.

Further, in the embodiment shown in FIG. 6, the piezoelectric substrate 31
Although two piezoelectric substrates 31 are illustrated, any number of piezoelectric substrates 31 may be used.
A structure in which the plate thickness is made as thin as possible and a plurality of layers are stacked is suitable because it can lower the voltage required to adjust the optical coupling efficiency. In other words, the configuration shown in FIG. 9 is superior. In the figure, the polarization direction of the piezoelectric substrate 31 is
When a substantially constant DC voltage is applied to the electrodes 91 adjacent to each other, the lengths 12 of the electrodes 91 expand and contract, making it possible to adjust the optical coupling efficiency. Moreover, since the first plane 41 and the second plane 42 of the piezoelectric substrate 31 can be prepared by polishing at the same time, the surface accuracy is good and the surface is hardened.

If the optical circuit board 16 is set, the optical circuit board 16 is hard to be distorted and the characteristics of the optical waveguide 16 are not deteriorated. Furthermore, in this configuration, it has been confirmed that when the piezoelectric substrates 310 are polarized in the same direction, the same effect can be obtained by using the structure shown in FIG. 10. FIG. 10 shows a sectional view of the main part, and angles 13 and 16° 31 are the same as FIG. 9. That is,
The polarization directions of the piezoelectric substrates 31 are the same, electrodes 101 are provided on both sides of one piezoelectric substrate 310, and the electrodes of the adjacent piezoelectric substrate are separated by an insulating material 1029, for example, an insulating adhesive. In this case, if a voltage was applied in the same direction, the same effect as in the embodiment shown in FIG. 9 could be obtained.

Further, the present invention shows the main structure, and even if the optical fiber 111 is provided at the other end of the optical waveguide 16 as shown in FIG. 11, it is also included in the present invention.

In the figure, it has the advantage of being able to compensate for the decrease in the optical coupling rate at 11.12, 13, 14, and 15 degrees, increasing the optical coupling efficiency, and also improving the decrease in optical coupling efficiency due to temperature changes. , can greatly contribute to the improvement of optical circuit devices,
The effect on the optical communication and control fields is significant and has high practical value.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a first conventional optical circuit device, FIGS. The figure shows the first aspect of the present invention.
4 is a block diagram of the same device in the second embodiment. FIG. 6 is a block diagram of the same device in the third embodiment. FIG. 7 is a block diagram of the same device in the fourth embodiment, FIG. 7 is a block diagram of the same device in the sixth embodiment, FIG. 9 is a block diagram of the same device in the sixth embodiment, and FIG. FIG. 10 is a configuration diagram of the same device according to the seventh embodiment, FIG. 10 is a configuration diagram of the same device according to the eighth embodiment, and FIG.
The figure is a configuration diagram of the same device according to the ninth embodiment. 11... Holding base, 12... First holding part, 13... Second holding part, 14...
Semiconductor laser, 16... Optical waveguide, 16...
...Optical circuit board, 31...Piezoelectric 13P substrate, 41...First plane, 42...Second plane, 43...Electrode , 61...3rd
Plane, 62... Fourth plane, 63... Electrode, 61... Piezoelectric substrate, 62... Piezoelectric substrate surface, 63... Electrode, 64...first end, 66...second end, 71...second
Holding substrate, 72... Taper support, 91...
...Electrode, 101... Electrode, 102...
...Insulating material, 111...Optical fiber. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure f/ Figure 2 ya' (bl JP-A-202408(5) uVzu Figure 6 Figure 11 fl -ri0-

Claims (4)

[Claims] (1) At least one comprising an optical circuit board provided with a semiconductor laser and an optical waveguide, and a supporting base, wherein the semiconductor laser is fixed to a first holding part of the supporting base, and an electrode is provided to a second holding part of the supporting base. An optical circuit device characterized in that a single piezoelectric substrate is fixed, and the optical circuit board is fixed on the piezoelectric substrate at a position where the optical waveguide and the semiconductor laser are optically coupled. (2) The electrode has a polarization direction substantially perpendicular to the first plane of the piezoelectric substrate that is the fixed surface with the second holding part, and is provided on the second plane of the piezoelectric substrate that is substantially parallel to the first plane and the first plane. 2. The optical circuit device according to claim 1, further comprising: (3) having a polarization direction substantially parallel to the first plane;
Claim 2, characterized in that electrodes are provided on a third plane of the piezoelectric substrate that is substantially perpendicular to the plane, and on a fourth plane of the piezoelectric substrate that is substantially parallel to the third plane. Optical circuit device described in section. (4) Two piezoelectric substrates having a polarization direction substantially perpendicular to the surface of the second holding part and differing in polarization direction by approximately 18o0 are bonded together, electrodes are provided on the surface of the piezoelectric substrate substantially parallel to the bonding surface, and the An optical circuit characterized in that a first end of the piezoelectric substrate remote from the semiconductor laser is fixed to the second holding part, and an optical circuit board is fixed to a second end of the piezoelectric substrate near the semiconductor laser. Device◎