JP2560822Y2 - Optical waveguide device - Google Patents

Description

[Detailed description of the invention] (Industrial application field) The invention relates to the improvement of the reliability of an optical waveguide device.
In particular, the present invention relates to protection of electrodes formed in the vicinity of an optical waveguide provided on the surface of an optical waveguide element and stability of optical waveguide characteristics.

(Prior art) To increase the reliability of the microstructure of semiconductors such as transistors and ICs, in order to protect the device from various external conditions such as stress and moisture, the surface or the entire device must be protected with resin or the like in advance. Covered with material. Further, in a semiconductor element, a structure for hermetically sealing the entire element is also employed. However,
Currently, there is no structure that can achieve complete reliability in optical waveguide devices, and considering the practicality of the technology in recent years with the rapid development of the optical industry and optical technology, it is urgent to increase the reliability of optical waveguide devices. It is necessary to establish a structure to achieve this.

(Problems to be Solved by the Invention) However, the structure used in conventional ICs, LSIs and the like cannot be directly applied to the optical waveguide device. That is, when the surface of the optical waveguide is covered with a resin or the like, depending on the surface protection material, the optical characteristics of the optical waveguide element may be changed due to the strain generated by curing, or the surface protection material may not provide sufficient moisture protection. Corrosion of the electrode material on the surface of the waveguide device occurs, and the desired life time of the optical waveguide device,
For example, a life time of 100,000 hours or more may not be obtained. Further, in a structure in which the entire element is hermetically sealed, as in the case of semiconductor element sealing, it is difficult to apply the optical fiber as it is in consideration of the fact that the optical fiber is connected to the waveguide element, and there is a disadvantage that the device size becomes large.

SUMMARY OF THE INVENTION An object of the present invention is to provide a highly reliable optical waveguide device which compensates for the drawbacks when the conventional general method is applied to an optical waveguide device.

(Means for Solving the Problem) The present invention is directed to an optical waveguide device including an optical waveguide formed on a substrate and an electrode formed near the optical waveguide, so as to cover at least the electrode formed near the optical waveguide. And a sealing material for hermetically sealing the inside of the container with an inert gas such as helium gas, nitrogen gas, Ar gas, or a vacuum.

(Operation) The surface of the optical waveguide element is protected by hermetic sealing with an inert gas or the like, thereby preventing moisture and stress on the element surface. In other words, electrode deterioration due to corrosion, preventing changes in the characteristics of the optical waveguide,
The reliability of the optical waveguide device can be improved.

(Example) Hereinafter, an example of this invention is described based on a drawing.
FIG. 1 is a sectional view showing an embodiment of the optical waveguide device according to the present invention. The crystal substrate 11 of the optical waveguide device has an optical waveguide 12, and an electrode 13 is provided on the surface of the crystal substrate 11 near the optical waveguide 12. And at least the electrode
The surface of the crystal substrate 11 including 13 is protected by hermetically sealing helium gas 16 with a container 14 made of quartz glass or the like.
As for the gas used for sealing, it is also possible to use an inert gas such as nitrogen gas, Ar gas, etc. in addition to helium gas,
Alternatively, it may be in a vacuum. For the sealing material 15, a resin such as polyimide, epoxy, or silicon is used.

By protecting the optical waveguide and the electrodes on the element surface by hermetic sealing, the influence of external conditions such as moisture and stress on the element surface can be prevented, and the reliability of the optical waveguide element can be improved. The material of the container 14 may be any other material such as a glass material, a plastic material, and a ceramic material as long as it plays a role in preventing moisture. Further, the substrate is not limited to a crystal substrate.

FIG. 2 and FIG. 3 are a perspective view and a cross-sectional view when the present invention is applied to a directional coupling type optical switch.

The optical waveguide 12 constitutes an optical directional coupler 19 by being disposed close to each other at intervals of about several μm, and an electrode 13 is disposed on the optical waveguide 12 via a buffer layer.
Since a strong electric field is applied to the electrode 13, without any protection, corrosion of the electrode material occurs, and the desired lifetime of the directional coupling type optical switch cannot be obtained. Further, when a surface protective material such as a resin is used, the optical characteristics of the directional coupling type optical switch may be changed due to the strain caused by curing. In this embodiment, only the optical directional coupler 19 of the directional coupling type optical switch and the electrode formed in the vicinity thereof are protected by hermetic sealing of an inert gas or the like using the container 14 so that the directional coupling is performed. Moisture and stress on the optical switch can be prevented.

Further, in the present embodiment, it is necessary to connect a plurality of optical fibers to the input and output ends of the optical waveguide element, and in such a case, it is difficult to seal the entire element as in a conventional semiconductor element. In addition, the shape becomes large. On the other hand, the present invention can be easily applied regardless of the connection of the optical fiber, and the size of the whole device hardly changes.

In this embodiment, an example of a directional coupling type optical switch is shown as an optical waveguide element, but the present invention is not limited to this. For example, the present invention can be applied to other types of optical switches, optical modulators, polarization controllers, and the like.

(Effects of the Invention) As described above, according to the present invention, it is possible to prevent electrode deterioration and change in optical characteristics of an optical waveguide device, and to achieve high reliability while maintaining the optical characteristics of the highly reliable optical waveguide device itself. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of an optical waveguide device according to the present invention, and FIGS. 2 and 3 are a perspective view and a cross-sectional view when the present invention is applied to a directional coupling type optical switch. 11 ... crystal substrate, 12 ... optical waveguide, 13 ... electrode, 14 ... container, 15
... sealing material, 16 ... helium gas, 17 ... buffer layer, 18 ...
Nitrogen gas, 19 ... Light directional coupler.

Claims (1)

(57) [Scope of request for utility model registration] 1. An optical waveguide device comprising an optical waveguide formed on a substrate and an electrode formed near the optical waveguide, a container installed to cover at least the electrode formed near the optical waveguide, and a container An optical waveguide device comprising an inert gas such as a helium gas, a nitrogen gas, and an Ar gas, or a sealing material for hermetically sealing with a vacuum.