Fiber Optic Multiplexer for Distributed MEMS Sensors

Smart and dynamic adaptable systems require distributed sensors over the strategic regions. Physical Optics Corporation (POC) proposes to design a fiber optic network multiplexer capable of reliably addressing and reading these transducers. The proposed sensor network uses Bragg gratings that are etched onto the fiber. The system uses a fiber optic amplifier doped with erbium and a wide-bandwidth light source. There are no in-series junctions along the fiber optic network, and only one light source and detector are used. This reduces signal losses and significantly improves reliability during temperature cycles and shocks. Simple MEMS pressure sensors will consist of a deformable diaphragm coupling with fiber optic Bragg gratings using etched V-grooves. The sensitivity, cross-sensitivity, and reliability of the system will be examined. The proposed fiber optic network has an energy efficiency 10,000 to 100,000 times higher than that of conventional passive multiplexing techniques. It also has extremely low cross talk (<-30 dB) with a high dynamic detection range. Hence, its simple circuitry has the potential of reading a few hundred sensors with ease. We will also study the possibility of using this technique to address large numbers of sensors.