Discretely tunable all-fiber Fabry-Perot laser based on birefringence fiber loop mirror and fiber Bragg grating

In this paper, we present a novel structure discretely tunable linear cavity fiber laser. A fiber Bragg grating (FBG) and a high birefringence fiber loop mirror are used as cavity reflectors. By changing the deflection of an equivalent-strength beam, the reflective wavelength of the FBG can be tuned accordingly. Since the reflectivity of the HiBi fiber loop mirror varies periodically, the output laser of this Fabry-Perot laser based on HiBi fiber loop mirror and FBG can be tuned discretely. From 1543.8nm to 1555.2nm, 15-wavelength lasers (SMSR>54dB) with approximately 0.8nm spacing have been obtained and the output laser intensity reaches about 2.5dBm in average. Nevertheless, some 0.8nm spacing lasers much weaker than the above lasers have also been observed. And they are expected to be eliminated by using narrower linewidth FBG as reflective mirror.