SOI基光波导传输损耗的研究

Study on Propagation Losses of SOI-Based Optical Waveguide

SOI基光波导中直波导的传输损耗包括模式失配损耗、内部散射损耗和表面散射损耗。为了研究直波导的传输损耗中3种损耗所占的比例,制作了相同宽度的条形和脊形波导,仿真分析和测试了2种波导的传输损耗。对于1550 nm的光,测试得到条形波导和脊形波导的传输损耗分别为-2.4 dB·cm^(-1)和-2.0 dB·cm^(-1),同样截面且忽略杂质缺陷和表面粗糙程度的理想波导的损耗均接近于0。通过对这些数据的分析,计算出条形波导表面散射损耗为-1.42 dB·cm^(-1),占总体损耗的59.2%,内部散射损耗为-0.98 dB·cm^(-1),占总体的40.8%。

The propagation losses of straight waveguides based on SOI include mode-field mismatching loss,internal scattering loss and surface scattering loss.In order to study the proportions of the three kinds of the straight waveguide propagation losses,the strip waveguide and rib waveguide with the same width were fabricated,and the propagation losses of the two waveguides were analyzed by simulation and experiment.For the light with wavelength of 1550 nm,measured propagation losses of the strip waveguide and rib waveguide were -2.4 dB·cm^(-1)and -2.0 dB·cm^(-1),respectively,while the loss of an ideal waveguide with the same cross section and neglecting impurity defects and surface roughness was close to zero.As a result,the surface scattering loss of strip waveguide was -1.42 dB·cm^(-1),accounting for 59.2% of the total.The internal scattering loss of strip waveguide was -0.98 dB·cm^(-1),accounting for 40.8% of the total.