Emerging 2D Semiconducting Materials: Tin Diselenide for Ultrafast Photonics

Abstract

SnSe 2 , a novel 2D semiconducting material with good photoelectric properties and tunable bandgaps structure, has been widely studied in high-performance photodetectors and superconductivity applications, etc. Herein, another excellent property, nonlinear optical absorption, is applied to ultrafast photonics. The measured nonlinear optical absorption curve of SnSe 2 with modulation depth of 5.52% is obtained. Q-switching and mode-locking in Er-doped fiber lasers based on SnSe 2 is reported. A Q-switched fiber laser can be obtained with a 0.5-m-long gain fiber and a 50:50 optical coupler. With 0.75-m-long active fiber and a 40:60 optical coupler, mode locking can be obtained. Furthermore, a third-order bound-state soliton pulse with a pulse duration of 882 fs can be achieved. The experimental results show that SnSe 2 is an excellent optical saturable absorber for the applications of ultrafast photonics.