Antimony selenide (Sb2Se3) as saturable absorber for Q-switching generation in an erbium-doped fiber laser

Abstract:

Based on the nonlinear saturable absorption properties (NSAP) of a two dimensional (2D) materials of antimony selenide (Sb₂Se₃), a Q-switched erbium-doped fiber (EDF) laser is systematically demonstrated. The Sb₂Se₃ nanosheets is prepared by liquid-phase exfoliation (LPE) method. After the sandwich-structured Sb₂Se₃ saturable absorber (SA) is fabricated, the NSAP are characterized and the modulation depth, the saturation intensity and the unsaturated loss are determined to be 25.2%, 2.02 MW/cm^₂, and 3.29%, respectively. When the as-prepared Sb₂Se₃-SA is integrated into the ring cavity, the laser operates at a stable Q-switching regime in the pump power range of 100-400 mW. The laser oscillates at the central wavelength of 1558.48 nm with a 3 dB bandwidth of 2.32 nm. Take the advantages of the Sb₂Se₃-SA, the pulse duration can be compressed from 40.49 kHz to 128.12 kHz. At the pump power of 400 mW, the Q-switching laser gives the narrowest pulse duration, highest average output power, largest pulse energy, and signal to noise-ratio (SNR) of 0.93 μs, 2.16 mW, 16.89 nJ, and 53 dB, respectively. Our new attempt on Sb₂Se₃-based Q-switched EDF laser proves that Sb₂Se₃ is a powerful candidate for ultrafast optical generation due to the characteristics of high modulation depth and high stability.

Key words:Q-switching; Sb2Se3; Erbium-doped fiber (EDF) laser; Saturable absorber (SA)