Low Power MEMS Retroreflectors for Optical Communication

摘要

Report developed under STTR contract W911NF-08-C-0006. In this Army Phase II STTR program, the BU and BMC project teams successfully designed, developed and tested a new low-power, light-weight and low-cost modulating retroreflector (MRR) system for free-space covert optical communication and remote sensor interrogation. The central component of the prototype is a MEMS modulator mirror, which is physically similar to a very low modulation reflective diffraction grating that has actively controlled groove depth and can operate at frequencies up to 1MHz. One facet of a hollow corner cube retroreflector consists of the MEMS mirror, which provides intensity. modulation of a reflected interrogating beam by switching from an unpowered flat mirror state to a powered diffractive state. The system is optimized for performance at 1550nm and has a field of view of 60 degrees. For covert operation it uses 'wake-up' circuitry to control a low-power shutter that remains closed between data transfers. The system's compact driver electronics employs power scavenging and resonant properties for minimal power consumption and extended.