A half-open cavity random fiber laser based on a single-mode fiber and fiber Bragg grating

A random erbium-doped fiber laser based on fiber Bragg grating (FBG) and single-mode fiber (SMF) was designed and realized experimentally in this study. For the proposed random fiber laser (RFL), the 10 km long SMF was used to generate Rayleigh scattering (RS) emissions, along with FBG to provide randomly distributed feedback in the cavity. In the experiment, the RFL laser threshold is 55 mW, as the pump power is increasingly improved to 175 mW. The RS effect is gradually apparent, and 1531.59nm laser beam was formed. The signal-to-noise ratio was 38.4 dB. The FBG was stretched for sensing applications, and the lasing wavelength was adjusted from 1531.59 to 1533.83 nm when the grating was stretched from 0 to 2000 mu epsilon.