RESUMO
We report what we believe to be the first demonstration of a laser-driven fiber optic gyroscope (FOG) built with an air-core fiber. Its phase noise is measured to be 130 murad/ radicalHz. When the sensing fiber is replaced with a conventional fiber, this figure drops to 12 murad/ radicalHz. Comparison between these values suggests that the air-core fiber gyro is most likely not limited solely by backscattering noise but by reflections at the solid-core/air-core interface. By minimizing additional noise sources and reducing the air-core fiber loss to its theoretical limit (approximately 0.1 dB/km), we predict that the backscattering noise of the laser-driven air-core FOG will drop below the level of current FOGs. Compared with commercial FOGs, this FOG will exhibit a lower noise, improved thermal and mean-wavelength stability, and reduced magnetic-field sensitivity.
RESUMO
We present a new optical fiber sensor interrogator specifically designed for an embedded instrumentation system. The proposed system consists of a super luminescent diode as a broadband source, a high speed tunable micro-electro-mechanical system (MEMS) filter, photodetector, and an integrated microprocessor for data aggregation, processing, and communication. The entire system is integrated together in a compact package to create a fiber "smart" sensor. The system is capable of interrogating a variety of multiplexed fiber sensors, processing the data, and communicating the results digitally. As an example, the system has been calibrated with an array of fiber Bragg grating sensors.
