Investigation on the Stability of WSe2-PVA Saturable Absorber in an all PM Q-Switched Fiber Laser

In this paper, we demonstrate an all polarization maintaining (PM) Q-switched erbium-doped fiber laser based on tungsten diselenide-polyvinyl alcohol (WSe
₂
-PVA) saturable absorber (SA) and investigated the stability of WSe
₂
-PVA SA in the laser. The all PM cavity isolated the environmental perturbation on the cavity birefringence so that the evolution of material properties of WSe
₂
-PVA SA during the Q-switched operation can be investigated based on the laser output. It is found that when heat accumulation reached a certain level in WSe
₂
-PVA SA, PVA in SA would first melt and perturb the transmission of SA; then, WSe
₂
in SA would be quickly damaged, resulting in a permanent increase of the SA loss. This work will benefit the research on obtaining a long-term stable all PM Q-switched lasers based on 2-D material saturable absorber.