2D self-assembled perovskite nanosheets as a nonlinear saturable absorber for passive Q-switched laser

Saturable absorbers (SAs) are essential devices for laser generation through passive Q-switch or mode-locking methods. Quantum-confined nanocrystals as excellent SAs have been attracted much attention. Self-assembled CsPbBr3 nanoplatelets (NPLs) were prepared at room temperature, which indicated nonlinear optical transmission with the modulation depth and the saturable intensity of 13.88% and 1.75 MW cm−2, respectively. The maximum repetition rate of CsPbBr3 NPLs is 1466 kHz, while corresponding pulse width is 69 ns. The nonlinear optical performance of CsPbBr3 NPLs indicate its potential applications in optical communication, laser pulses and nonlinear optics.