Silicon photonic MEMS 2 × 2 elementary switch based on horizontal adiabatic directional couplers
Yinpeng Hu, Jiayue Zhu, Ye Lu, Yunzhi Liu, Huan Li, Daoxin Dai · Optics Express · 2025
High-speed data processing requires large-scale photonic integrated circuits, in which photonic switches serve as essential components for reconfiguration. Micro-electromechanical-system (MEMS)-based photonic switches, particularly those utilizing adiabatic directional couplers (ADCs), offer advantages such as broad bandwidth, exceptional fabrication tolerance, and digital operation. However, previous ADC-based switches are limited to 1 × 2 configurations, restricting their compatibility with diverse array topologies. Here, we propose a novel silicon photonic MEMS 2 × 2 switch based on horizontal ADCs (HADCs) which is compatible with all mainstream array topologies. In simulation, the switch features low insertion loss of 6–19 mdB/7–32 mdB and low crosstalk of –44.1 – –37.4 dB/–32 – –22.6 dB in broad bandwidth of 1500–1600 nm in the OFF/ON state, respectively. Experimental results demonstrate insertion loss of 0.15–0.7 dB/1.1–1.6 dB, crosstalk of –48.6 – –40.1 dB/–9.2 – –8.4 dB in the OFF/ON state, respectively. The measured switch performance in the ON state can be further improved by using more comprehensive coordinated photonic/mechanical design or low-strain SOI wafers to suppress the waveguide buckling in our future work. Additionally, fast ON/OFF switching speed of 2.6/1.8 μs and reliable durability of >10 9 switching cycles have been demonstrated experimentally. This 2 × 2 switch design addresses critical limitations of previous architectures and is a promising approach for versatile applications including microwave photonics, photonic interconnects, LiDAR, and spectrometers.