Optical Microphone Based on Sagnac Interferometer with Polarization Maintaining Optical Fibers
Jarosław Piotr Turkiewicz
This paper describes possible use of Sagnac interferometer, based on the polarization maintaining fiber, as an optical microphone. Operation of investigated setup is based on the refractive index changes induced by acoustic wave and fiber strain. In the conducted experiment, Sagnac interferometer working as an optical microphone was able to achieve 6 dB bandwidth up to 4.5 kHz. Possibilities for linear operation was examined as well. Experimental results are preceded by a mathematical analysis of the operating principles.