We report several techniques affecting line-width and long-term stability of single longitudinal mode (SLM) random fiber laser (RFL) based on Rayleigh backscattering in a standard single mode fiber as distributed mirrors, and a semiconductor optical amplifier (SOA) as the gain medium. Three parameters were investigated; single mode fiber (SMF) length, the optical filter bandwidth, and the type of the cavity reflecting mirror. Line-width of the laser was measured at three values of SMF length; 100 m, 1 km, and 2 km. Impact of the optical filter bandwidth on the laser line-width was studied. Finally, long-term stability was characterized for two types of reflecting mirrors; a silver coated mirror, and a Faraday rotating mirror (FRM).
A novel narrow line-width Single longitudinal mode (SLM) dual wavelength random fiber laser of 20 nm separation between wavelengths of 1530 and 1550 nm is presented. The laser is based on Rayleigh backscattering in a standard single mode fiber of 2 Km length as distributed mirrors, and a semiconductor optical amplifier (SOA) as the optical amplification medium. Two optical bandpass filters are used for the two wavelengths selectivity, and two Faraday Rotator mirrors are used to stabilize the two lasing wavelengths against fiber random birefringence. The optical signal to noise ratio (OSNR) was measured to be 38 dB. The line-width of the laser was measured to be 13.3 and 14 KHz at 1530 and 1550 nm respectively, at SOA pump current of 370 mA.
We report a novel narrow line width single longitudinal mode random laser at wavelength of 1550 nm. The laser is based on Rayleigh backscattering in a standard single mode fiber (SMF-28e) as a distributed mirror [1,2], and the semiconductor optical amplifier (SOA) as the gain medium. The optical signal to noise ratio was measured to be 34 dB. The line width of the laser was observed to be monotonically increasing with SOA bias current. The minimum line width of the laser was measured to be 6.5 KHz at SOA current of 170 mA. The maximum value of optical power was measured to be 4 mW.