Micro-structured optic fiber system for pressure sensing

The micro-structured optic fiber system has been designed, built and tested. The whole system is effectively enough to monitor micro-vibration movement caused by acoustic wave. The developed system has a strong ability to anti-EM interference. The thin film is specially designed and fabricated using RIE method. The diameter of the film is φ200μm and the thickness is thin enough to sense micro-vibration. Single fiber is used to generating, transmitting and receiving optical signal. The optical fiber coupler is used to direct the light from laser diode onto the film and to guide reflected signal to the detector. The distance between the film and fiber end is fixed. The light modulation function, the system noises and the way against noises are discussed. Factors influencing system sensitivity are also investigated through our test results.