Experimental and numerical study of high order Stokes lines in Brillouin-erbium fiber laser

Abstract

We experimentally study the dependences of high-order Stokes lines on the erbium-doped fiber (EDF) pump power PEDF, the Brillouin pump (BP) power PBP, and its working wavelength in a multiwavelength Brillouin erbium-doped fiber laser (MBEFL). By using the rate and propagation equations, and the coupled wave equations of stimulated Brillouin scattering, we establish a lumped model to describe the MBEFL. Numerical simulations show that the number of Stokes lines can be increased by decreasing the spacing between the BP wavelength and the EDF peak gain or PBP as long as it is larger than a critical value PBP(cr)=1.7 mW, or by increasing PEDF without reaching a saturation value PEDF(cr)=250 mW. However, when PBP and PEDF are varied beyond PBP(cr) and PEDF(cr), respectively, the number of Stokes lines is reduced, accompanied by some self-lasing cavity modes. These results by numerical simulation are consistent with experimental observations from the MBEFL.