Real-Time Optical MEMS-based Seismometer

Currently, nuclear tests are monitored by the International Monitoring System (IMS), a network of automated seismic stations that record any evidence of clandestine nuclear explosions. Although geographically extensive and relatively accurate, this system occasionally fails to detect man-made seismic activity. This project will develop a low-cost miniature seismometer based on the latest developments in Optical Micro Electrical Mechanical Systems (Optical MEMS) technology. With Optical MEMS, which is based on high-Q-factor optical resonances, the detection of accelerations as small as 0.5 nano-g can be achieved with a dynamic range of 120dB. The seismometer will be rugged, capable of unattended operation, and capable of being interrogated in real time. Phase I will establish a proof-of-concept for the instrument, both analytically and experimentally, and a prototype instrument will be designed. This design will then serve as a baseline for the fabrication and demonstration of the instrument in Phase II. Commercial Applications and other Benefits as described by the awardee: The capability to detect nano-accelerations should be attractive to many industries, including (1) the mining and oil-prospecting industries for monitoring explosions used for excavation and surveys; (2) the geologic industry for seismic monitoring; (3) the surveillance industry for the detection of entry, foot steps, and tampering; (4) the architectural industry for measuring skyscraper motion, whether caused by the wind or seismic activity; and (5) space exploration as an in-flight accelerometer.