Ultra-high extinction ratio and low power silicon thermo-optic switch

• Jin Wang, shangqing shi, Hongsheng Niu, Suzhe Gao, Bo Yang, Shihao Zhang, Cheng Wei, Yifei Chen, Chen Guo, Wanghua Zhu, Guohua Hu, Yiping Cui, and Bin Yun
• received 01/31/2024; accepted 04/10/2024; posted 04/12/2024; Doc. ID 520209
• Abstract: The silicon thermo-optic switch (TOS) is one of the most fundamental and crucial blocks in large-scale silicon photonics integrated circuits (PICs). An energy-efficient silicon TOS with ultra-high extinction ratio can effectively mitigate crosstalk and reduce power consumption in optical systems. In this letter, we demonstrate a silicon TOS based on cascading Mach-Zehnder interferometers (MZIs) with spiral thermo-optic phase shifters. The experimental results show that an ultra-high extinction ratio of 58.8 dB is obtained, and the switching power consumption is as low as 2.32 mW/ without silicon air trench. The rise time and fall time of the silicon TOS are about 10.8 s and 11.2 s, respectively. Particularly, the figure of merit (FOM) has been improved compared with previously reported silicon TOS. The proposed silicon TOS may find potential applications in optical switch arrays, on-chip optical delay lines, etc.