We propose and demonstrate a polarimetric Er3+-doped fiber distributed-feedback laser sensor in which a force applied transversely along the fiber laser induces a birefringence that gives rise to a change in the beat frequency between the two orthogonally polarized laser modes. We measure a sensitivity of ~9.6 GHz/(N/mm), a wide dynamic range with stable two-mode operation for frequency separations up to 50 GHz, and high sensor resolution owing to the narrow beat frequency bandwidth of <10 kHz. The temperature sensitivity is dominated by the temperature dependence of the inherent birefringence, which was measured to be −130 kHz/°C. The sensor permits independent pressure–force and temperature measurements.
© 1996 Optical Society of America
J. T. Kringlebotn, W. H. Loh, and R. I. Laming, "Polarimetric Er3+-doped fiber distributed-feedback laser sensor for differential pressure and force measurements," Opt. Lett. 21, 1869-1871 (1996)