In this communication, we demonstrate a passive mode-locked Er:Yb co-doped double-clad fiber laser using a tapered microfiber topological insulator (Bi2Se3) saturable absorber (TISA). The topological insulator is drop-casted onto the tapered fiber and optically deposited by optical tweezer effect. We use a ring laser setup including the fabricated TISA. By carefully optimizing the cavity losses and output coupling ratio, the mode-locked laser can operate in L-band with a high average output power. At a maximum pump power of 5 W, we obtain the 91st harmonic mode-locking of soliton bunches with a 3dB spectral bandwidth of 1.06nm, a repetition rate of 640.9 MHz and an average output power of 308mW. As far as we know, this is the highest output power yet reported of a mode-locked fiber laser operating with a TISA.
The effect of an external continuous wave (cw) on the operating regime of a passively mode-locked double-clad fiber
laser, operating in the anomalous dispersion regime, is experimentally investigated. Starting from different soliton
distributions, we demonstrate that, under specific conditions, the cw signal forces the principal laser to operate in
harmonic mode-locking regime.
We investigate the soliton pattern formation in an erbium-doped figure-of-eight double-clad fiber laser. The mode-locking
is realized with a nonlinear amplifying loop mirror. Different soliton complexes have been obtained similar to
those obtained when the mode-locking is achieved through the nonlinear polarization rotation technique.