Du Binjian, Pan Han, Pan Zhongben, Chu Hongwei, Li Ying, Zhao Shengzhi, Li Dechun
Opt Express. 2025 Jul 14;33(14):30799-30810. doi: 10.1364/OE.569414.
In this work, two-dimensional (2D) PdX (X = S, Se) nanosheets were successfully fabricated via the ultrasound-assisted liquid-phase exfoliation (LPE) method and characterized comprehensively. Employing open-aperture (OA) Z/I-scan techniques, the nonlinear absorption (NLA) properties of the samples in the mid-infrared (MIR) region were systematically investigated, which revealed that PdX (X = S, Se) nanosheets exhibited excellent saturable absorption characteristics at 3 μm. The large effective NLA coefficient, high modulation depth, and low saturation intensity highlight their potential as high-performance saturable absorbers (SAs). Subsequently, to the best of our knowledge, PdX (X = S, Se) were used as SAs (PdS-SA, PdSe-SA) to demonstrate a passively Q-switched (PQS) Er:YAP laser at 3 μm for the first time. Stable pulsed outputs were achieved with the shortest pulse durations of 525 ns and 369 ns at repetition rates of 93.22 kHz and 106.02 kHz, respectively, for PdS-SA and PdSe-SA. These results demonstrate that PdX (X = S, Se) are promising candidate materials for SAs in the MIR pulsed laser systems, while also revealing the significantly enhanced NLA and optical modulation characteristics of PdSe compared to PdS.
在本工作中，通过超声辅助液相剥离（LPE）法成功制备了二维（2D）PdX（X = S，Se）纳米片，并对其进行了全面表征。采用开孔（OA）Z扫描技术，系统研究了样品在中红外（MIR）区域的非线性吸收（NLA）特性，结果表明PdX（X = S，Se）纳米片在3μm处表现出优异的饱和吸收特性。大的有效NLA系数、高调制深度和低饱和强度突出了它们作为高性能饱和吸收体（SAs）的潜力。随后，据我们所知，首次将PdX（X = S，Se）用作饱和吸收体（PdS-SA，PdSe-SA）来演示3μm被动调Q（PQS）Er:YAP激光器。对于PdS-SA和PdSe-SA，分别在93.22kHz和106.02kHz的重复频率下实现了最短脉冲持续时间为525ns和369ns的稳定脉冲输出。这些结果表明，PdX（X = S，Se）是MIR脉冲激光系统中饱和吸收体的有前途的候选材料，同时也揭示了与PdS相比，PdSe的NLA和光调制特性显著增强。
