We have demonstrated a single fiber probe for simultaneous measurement of external refractive index and temperature based on two interferometers: a reflection-mode long-period grating (LPG) for refractometry and an intrinsic Fabry-Perot interferometer (IFPI) for temperature measurement. Since the output signal of the combined structure is a superposition of signals produced by both sensors, which have different spatial frequencies, the original signals needed for the index and temperature measurements can be separated and recovered through digital filters.
© 2005 Optical Society of America
Fiber Optics and Optical Communications
Dae Woong Kim, Fabin Shen, Xiaopei Chen, and Anbo Wang, "Simultaneous measurement of refractive index and temperature based on a reflection-mode long-period grating and an intrinsic Fabry-Perot interferometer sensor," Opt. Lett. 30, 3000-3002 (2005)