Metal halide perovskite has generated significant attention due to its high optical absorption coefficient, the tunability of bandgap, and its solution processing properties, all of which have led to a range of applications including solar cells, photodetectors, light-emitting diodes and lasers. However, the material's application as an optical modulator for high-energy ultrafast lasers is still limited by its slow nonlinear optical response, low damage threshold and the inferior stability. Herein, we developed a saturable absorber (SA) with the thermally stable Cs0.15FA0.85PbI2.85Br0.15 perovskite thin films as an optical modulator towards the near-infrared nanosecond passively Q-switched Nd:YAG laser generation for the first time. The Cs0.15FA0.85PbI2.85Br0.15 perovskite SA optical modulator produced an exceptional nonlinear optical response with a notable modulation depth of 15.1%, an ultrashort recovery time of 52.46 ps, and a high optical damage threshold exceeding 275.9 mJ/cm2. Of further significance, it displayed an excellent operational stability, and when incorporated into the oscillator of the Nd:YAG laser, allowed for a stable operation of 166 ns pulse laser with a center wavelength of 1.06 μm. The findings provide a pathway for the employment of the Cs0.15FA0.85PbI2.85Br0.15 perovskite SA optical modulator in near-infrared ultrafast laser applications.

中文翻译：

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近红外光调制器的热稳定钙钛矿的非线性光学响应


金属卤化物钙钛矿因其高光吸收系数、带隙的可调谐性及其溶液加工特性而受到广泛关注，所有这些都导致了包括太阳能电池、光电探测器、发光二极管和激光器在内的一系列应用。然而，该材料作为高能超快激光器的光调制器的应用仍然受到其缓慢的非线性光学响应、低损伤阈值和较差的稳定性的限制。在此，我们开发了一种可饱和吸收剂 （SA），其热稳定的 Cs0.15FA0.85PbI2.85Br0.15 钙钛矿薄膜作为光调制器，首次用于近红外纳秒被动 Q 开关 Nd：YAG 激光器的产生。Cs0.15FA0.85PbI2.85Br0.15 钙钛矿 SA 光调制器产生了出色的非线性光响应，具有 15.1% 的显着调制深度、52.46 ps 的超短恢复时间和超过 275.9 mJ/cm2 的高光损伤阈值。更重要的一点是，它表现出出色的操作稳定性，当集成到 Nd：YAG 激光器的振荡器中时，允许中心波长为 1.06 μm 的 166 ns 脉冲激光器稳定运行。研究结果为Cs0.15FA0.85PbI2.85Br0.15钙钛矿SA光调制器在近红外超快激光应用中的应用提供了一条途径。