Accurate theoretical and experimental characterization of optical grating coupler

作者:Fesharaki Faezeh*; Hossain Nadir; Vigne Sebastien; Chaker Mohamed; Wu Ke
来源:Optics Express, 2016, 24(18): 21027-21037.
DOI:10.1364/OE.24.021027

摘要

Periodic structures, acting as reflectors, filters, and couplers, are a fundamental building block section in many optical devices. In this paper, a three-dimensional simulation of a grating coupler, a well-known periodic structure, is conducted. Guided waves and leakage characteristics of an out-of-plane grating coupler are studied in detail, and its coupling efficiency is examined. Furthermore, a numerical calibration analysis is applied through a commercial software package on the basis of a full-wave finite-element method to calculate the complex propagation constant of the structure and to evaluate the radiation pattern. For experimental evaluation, an optimized grating coupler is fabricated using electron-beam lithography technique and plasma etching. An excellent agreement between simulations and measurements is observed, thereby validating the demonstrated method.