Generation of bright–dark solitons in an Er-doped fiber laser employing InSb as a saturable absorber

In this paper, an indium antimonide (InSb) saturable absorber (SA) was successfully fabricated. The saturable absorption properties of the InSb SA were studied, and they show a modulation depth and a saturable intensity of 5.17% and 9.23 MW/cm, respectively. By employing the InSb SA and building the ring cavity laser structure, the bright–dark soliton operations were successfully obtained by increasing the pump power to 100.4 mW and adjusting the polarization controller. As the pump power increased from 100.4 to 180.3 mW, the average output power increased from 4.69 to 9.42 mW, the corresponding fundamental repetition rate was 2.85 MHz, and the signal-to-noise ratio was 68 dB. The experimental results show that InSb with excellent saturable absorption characteristics can be used as a SA to obtain pulse lasers. Therefore, InSb has important potential in fiber laser generation, further applications in optoelectronics, laser distance ranging, and optical fiber communication, and it can be widely developed.