Grating coupler and preparation method thereof

Abstract

The invention provides a grating coupler and a preparation method thereof. The preparation method of the grating coupler comprises the following steps: providing an SOI substrate, wherein the SOI substrate comprises a silicon substrate layer, a silicon dioxide middle layer and a silicon top layer from bottom to top; etching the silicon top layer to form a first coupling grating; forming a Poly-Silayer on the silicon top layer; etching the Poly-Si layer to form a second coupling grating; stacking the second coupling grating and the first coupling grating in a staggered manner. According to thegrating coupler, the insertion loss of the grating coupler is reduced by forming the Poly-Si layer on the silicon top layer, the insertion loss is further reduced through the offset design of the second coupling grating and the first coupling grating, and the tolerance of a grating preparation process can be improved through the offset design.

Description

technical field [0001] The invention relates to the technical field of photonic devices, in particular to a grating coupler on an SOI substrate and a preparation method thereof. Background technique [0002] The development of silicon-based optoelectronics compatible with CMOS technology has enabled the integration of low-cost technology for producing silicon chips with optical technology, breaking the boundaries between traditional electronic computing and optical fiber communication; at the same time, high-speed electronic circuits based on silicon CMOS technology The development of the technology has made the high-performance optical circuit and circuit monolithic integrated chip with certain functions a reality. SOI is the English acronym for Silicon-On-Insulator (Silicon on Insulator). The SOI substrate is composed of a silicon substrate layer, a silicon dioxide middle layer and a silicon top layer from bottom to top. Among them, the silicon substrate layer, the silicon...

AI Technical Summary

Problems solved by technology

[0006] The object of the present invention is to provide a grating coupler and its preparation method. The grating coupler of the present invention can solve the problem of excessive loss of the grating coupler in the prior art, has a simple process, can reduce the on-chip loss of silicon photonic chips, and can Lower power requirements for light sources or receiver sensitivity, reducing system energy consumption and cost

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