Chang Yuhua, Dong Bowei, Ma Yiming, Wei Jingxuan, Ren Zhihao, Lee Chengkuo
Opt Express. 2020 Mar 2;28(5):6251-6260. doi: 10.1364/OE.382226.
Vernier effect has been captivated as a promising approach to achieve high-performance photonic sensors. However, experimental demonstration of such sensors in mid-infrared (MIR) range, which covers abundant absorption fingerprints of molecules, is still lacking. Here, we report Vernier effect-based thermally tunable photonic sensors using cascaded ring resonators fabricated on the silicon-on-insulator (SOI) platform. The radii and the coupling gaps in two rings are investigated as key design parameters. By applying organic liquids on our device, we observe an envelope shift of 48 nm with a sensitivity of 3000 nm/RIU and an intensity drop of 6.7 dB. Besides, our device can be thermally tuned with a sensitivity of 0.091 nm/mW. Leveraging the characteristic molecular absorption in the MIR, our work offers new possibilities for complex index sensing, which has wide applications in on-chip photonic sensors.
游标效应已被视为实现高性能光子传感器的一种很有前景的方法。然而，在覆盖丰富分子吸收指纹的中红外（MIR）范围内，此类传感器的实验演示仍然缺乏。在此，我们报告了基于游标效应的热可调谐光子传感器，该传感器使用在绝缘体上硅（SOI）平台上制造的级联环形谐振器。研究了两个环的半径和耦合间隙作为关键设计参数。通过在我们的器件上施加有机液体，我们观察到包络线位移为48 nm，灵敏度为3000 nm/RIU，强度下降为6.7 dB。此外，我们的器件可以进行热调谐，灵敏度为0.091 nm/mW。利用MIR中的特征分子吸收，我们的工作为复折射率传感提供了新的可能性，这在片上光子传感器中有广泛应用。
