基于GST薄膜的弯曲波导相变光学器件光学仿真与分析

Optical Simulation and Analysis of Curved-Waveguide Phase-Change Optical Devices Based on GST Thin Film

摘要:

研究了相变光学器件的光传输性能,使用时域有限差分法建立覆盖Ge₂Sb₂Te₅(GST)薄膜的弯曲波导模型,得到了在晶态和非晶态两种情况下GST的面积、厚度和在弯曲波导中的位置对光传输效率及损耗的影响规律。结果表明:GST的最优覆盖面积为0.415μm²,厚度为17nm,器件光传输不受GST覆盖位置影响,光传输对比度最佳达到90.8%,插入损耗低至0.321dB,在1500~1670nm波长范围内能够实现宽光谱并行传输。该器件尺寸小,消光比大,理论上满足提高光计算准确率的需求。研究结果对于非易失性、并行集成光子矩阵计算单元器件的研制具有一定的参考意义。

Abstract:

This article discusses the optical transmission performances of phase-change optical devices. A bending waveguide model covering Ge₂Sb₂Te₂ (GST) thin films was established using the finite difference time domain method. The influences of the GST area, thickness, and position in the bending waveguide on the optical transmission efficiency and loss were obtained in both the crystalline and amorphous states. The results indicated that when the optimal coverage area of the GST was 0.415μm², and the thickness was 17nm, the optical transmission of the device was not affected by the GST position. The maximum contrast of the optical transmission reached 90.8%, and the insertion loss was as low as 0.321dB. Broadband parallel transmission could be achieved in a wavelength range of 1500~1670nm. The device had a small size and high extinction ratio, which theoretically met the requirement for enhancing the accuracy of optical calculations. This study is significant in the development of non-volatile, parallel integrated photon matrix computing unit devices.