Optical waveguide and fabrication method thereof, and method for reducing sidewall scattering loss of iii-v semiconductor waveguide

Abstract

The invention relates an optical waveguide, a manufacturing method thereof, and a method for reducing the scattering loss of the side wall of a V-III semiconductor waveguide. The optical waveguide comprises a core layer; the surface of the core layer is coated with a limiting layer; the limiting layer comprises an aluminum oxide clad layer; and a smooth side wall is formed between the aluminum oxide clad layer and the core layer. According to the optical waveguide, the manufacturing method thereof, and the method for reducing the scattering loss of the side wall of the V-III semiconductor waveguide, an aluminum-containing V-III semiconductor is adopted as the core layer material of the optical waveguide; the optical waveguide is defined through aluminum oxidation; on the one hand, the aluminum oxidation-defined optical waveguide is realized, so that the aluminum-containing semiconductor is surround by a Al2O3 medium, and the refractive index difference of the aluminum-containing semiconductor and the Al2O3 medium is small, and therefore, the sensitivity of scattering loss to the roughness of the side wall of the waveguide is decreased, and on the other hand, an aluminum oxidation process is a wet oxidation technology, such kind of chemical reaction takes effect at the molecular level, and therefore, the roughness of the side wall of the waveguide structure defined by aluminum oxidation is undoubtedly far smaller than the roughness of the side wall of a waveguide structure defined by dry etching.

Description

technical field [0001] The present application relates to an optical waveguide and a manufacturing method thereof, and a method for reducing scattering loss on the side wall of a III-V semiconductor waveguide. Background technique [0002] Scattering loss caused by rough sidewalls is an insurmountable problem for all passive optical waveguides, especially for large-scale optical waveguides, which may become the ultimate limiting factor for their performance improvement. For the ridge waveguide defined by III-V materials, since the refractive index of III-V materials is greater than 3, while the refractive index of air is 1, the large refractive index difference makes its scattering loss very important to the sidewall roughness. Therefore, in order to reduce the waveguide scattering loss, the usual method is to obtain an optical waveguide structure with smooth side walls. Obtain high-quality optical waveguides. This method makes the sidewall roughness of the optical wavegui...

AI Technical Summary

Problems solved by technology

This method makes the side wall roughness of the optical waveguide greatly dependent on each step of the process, so that the smoothness of the side wall is limited, and the cost of obtaining an optical waveguide with a truly smooth side wall increases and the yield decreases.

[0003] Large-scale and high-quality factor III-V semiconductor ring resonators are the basis and key to realize monolithic integrated optical gyro. For this large-scale III-V group ring resonator, due to the high refractive index of III-V semiconductors, large The large scattering loss caused by the difference in refractive index and the roughness of the side wall becomes the final factor restricting the improvement of its quality factor, which directly restricts the resolution of the monolithic integrated optical gyroscope.

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