Optical Fiber Sensors Based on Fiber Ring Laser Demodulation Technology.

A review for optical fiber sensors based on fiber ring laser (FRL) demodulation technology is presented. The review focuses on the principles, main structures, and the sensing performances of different kinds of optical fiber sensors based on FRLs. First of all, the theory background of the sensors has been discussed. Secondly, four different types of sensors are described and compared, which includes Mach-Zehnder interferometer (MZI) typed sensors, Fabry-Perot interferometer (FPI) typed sensors, Sagnac typed sensors, and fiber Bragg grating (FBG) typed sensors. Typical studies and main properties of each type of sensors are presented. Thirdly, a comparison of different types of sensors are made. Finally, the existing problems and future research directions are pointed out and analyzed.