Numerous fiber optic sensors have been developed that utilize wavelength modulation to encode the values of sensed parameters of interest. Two basic techniques have been used to process the return signals from these types of sensors: Fabry-Perot cavity modulation and diffraction grating plus CCD array. The first of these suffers from a limited spectral range while the second is limited in speed due to the serial readout of the CCD array. A thin film Faraday phase grating modulated by an external magnetic field in combination with a single large area photodetector is able to overcome these limitations. In this paper we develop a theoretical model for the performance of such a device and compare it with experimental results. Finally, the practical application of this technology is discussed.

Date Published: 21 September 1994
PDF: 10 pages
Proc. SPIE 2294, Distributed and Multiplexed Fiber Optic Sensors IV, (21 September 1994); doi: 10.1117/12.187392

Published in SPIE Proceedings Vol. 2294:
Distributed and Multiplexed Fiber Optic Sensors IV
Alan D. Kersey; John P. Dakin, Editor(s)