拉曼抑制光频梳微腔的设计与仿真

为了解决回音壁模式下的微腔在产生光频梳时受拉曼效应的影响,尤其在重频GHz时难以产生平滑的光梳谱的问题。首先,设计并调节波导和微环的耦合长度;然后,优化耦合角度,调整微环与波导之间的匹配模式,降低在长波段的耦合Q值,增加拉曼产生的阈值,抑制拉曼效应。通过仿真分析得出,相较于一般的直波导微环耦合结构,设计的弯曲波导微环在短波长处拉曼阈值增加了3倍,且在短波长处产生的光频梳功率提高了20 dB。为回音壁模式微腔结构的设计提供了一定的参考价值。

Design and simulation of Raman suppression optical comb microcavity

In order to solve the problem of the Raman effect on the generation of optical frequency comb in microcavities under whispering gallery mode, especially at GHz repetition frequencies, which makes it difficult to generate a very smooth optical comb spectrum. Firstly, design and adjust the coupling length between the waveguide and the microring. Then, optimize the coupling angle, adjust the matching mode between the waveguide and the microring, the coupling Q value in the long wavelength is reduced, the threshold of Raman generation is increased, and the Raman effect is suppressd. According to the simulation analysis, compared with the general straight waveguide microring coupling structure, the designed pully waveguide microring has three times increase in the Raman threshold at the short wavelength, and the optical frequency comb power generated at the short wavelength has increased by 20 dB. This provides a certain reference value for the design of whispering gallery mode microcavity structures.