Radio-frequency (rf) beat frequencies between two longitudinal modes and two polarization modes of a birefringent dual-longitudinal-mode moiré distributed-feedback fiber laser are employed to measure strain and temperature simultaneously. Operating entirely in the rf domain, this approach potentially allows one to employ low-cost and precise rf measuring techniques. A strain–temperature cross sensitivity of the strain- and the thermo-optic coefficients, which can be neglected in wavelength-based grating sensors, has been observed. The achieved sensor accuracy was ∓15 με and ∓0.2 °C.
© 2001 Optical Society of America
(060.2370) Fiber optics and optical communications : Fiber optics sensors
(140.3490) Lasers and laser optics : Lasers, distributed-feedback
(140.3510) Lasers and laser optics : Lasers, fiber
(280.3420) Remote sensing and sensors : Laser sensors
O. Hadeler, M. Ibsen, and M. N. Zervas, "Distributed-feedback fiber laser sensor for simultaneous strain and temperature measurements operating in the radio-frequency domain," Appl. Opt. 40, 3169-3175 (2001)