A Self-Latching MEMS Optical Interrupter With Status Monitoring for Laser Initiation System

A novel self-latching MEMS optical interrupter with status monitoring is proposed to enhance the safety of laser initiation system (LIS) by preventing long-term heat accumulation and reducing response time. The electrothermal-actuated interrupter consists of an optical fiber alignment actuator, a positive latching actuator (PLA), and a reverse blocking actuator, each coupled with a status monitoring unit. The PLA is equipped with an interlock mechanism for self-latching capability. The interrupter's operating state is monitored using cantilever beams that function as travel switches. The interrupters are fabricated using deep reactive ion etching (DRIE) on silicon-on-insulator (SOI) wafers. Experiments are conducted to study the behavior of the proposed interrupter, which demonstrates the successful implementation of its self-latching and status-monitoring features. The interrupter has a switching time of less than 64 ms and exhibits an optical efficiency ranging from 63% to 68% (1.67-1.97-dB insertion loss) with a maximum power transfer of 865 mW from a 1272-mW input.