将二维材料硒化钨(WSe2)与聚合物聚乙烯醇(PVA)混合制成饱和吸收体薄膜, 在掺铒保偏光纤激光器中实现了稳定的调Q运转。全保偏的腔体能够最大程度减少环境对激光腔双折射的扰动, 在此基础上, 研究了硒化钨聚乙烯醇(WSe2-PVA)饱和吸收体薄膜在调Q运转中的稳定性。研究发现, 当材料中的热量累积到一定阈值后, 聚合物基底材料首先进入熔融状态, 随后热量在薄膜中进一步累积, 导致硒化钨受热损坏, 表现为饱和吸收体薄膜的损耗急剧增加。

In this paper, we fabricated thin-film saturable absorber by mixing 2D material tungsten diselenide (WSe2) and polymer polyvinyl alcohol (PVA). The WSe2-PVA saturable absorber (SA) was incorporated in an erbium-doped polarization maintaining (PM) fiber laser, and stable Q-switched operation was realized. An all PM cavity can reduce environmental perturbation on the cavity birefringence. Based on this PM cavity, we investigated the stability of WSe2-PVA SA in the Q-switched operation. It is found that when the heat accumulation reached a certain threshold in the SA, the polymer substrate firstly melted and more heat accumulateed quickly. As a result, WSe2 was damaged, showing a significant increase of SA loss.