Temperature insensitive optical fiber laser bend sensor with a low detection limit

摘要

A fiber in-line Mach-Zehnder interferometer based on a sandwich structure of single mode fiber-thin core fiber-single mode fiber is inserted into a fiber ring laser cavity to form a fiber laser bend sensor. Such a sensor is temperature insensitive, has a large output light intensity ∼ 0.61 dBm, a high optical signal-to-noise ratio of ∼ 63 dB, a narrow spectral width of ∼ 0.01 nm at the lasing wavelength and a good bending sensitivity of ∼ 1.04 nm/m-1, which gives a low detection limit of ∼ 4.37 × 10-2m-1.