Fiber Optic Dynamic Strain Sensors for Seismic Monitoring

"Optiphase, Inc. proposes the development of a fiber optic seismic sensing system suitable to enhance Army INSCOM capabilities. This system will utilize EMI immune "all-fiber" sensor array elements configurable for both TDM and WDM multiplexing capable ofthe required high-speed data acquisition rates. The fiber seismic sensor design will utilize interferometric transduction methods to assure the highest possible sensitivity. The system design implements DSP control of sensor array interrogation processesto assure real-time acquisition and a fast data port to a standard host computer. Phase I involves the development of a suitable seismic sensor. The design focus involves use of Fiber Bragg Gratings (for efficient array architecture), and a mechanicallyefficient fiber transducer design to assure high sensitivity and bandwidth. Sensor designs will be evaluated for performance and capabilities for integration into a multi-channel array (design). Phase II will involve the development and field testing ofa real-time multi-channel seismic sensor system, suited to Army requirements. This seismic sensor system will be developed for and have direct application to the Army's Prophet Block IV program. The design evolved however can be generalized as a highperformance, multi-channel dynamic sensing system. Such designs have numerous "outside" applications, such as general surveillance, industrial process control, geophysical sensing, pow