Mode-Locked Characteristic of L-Band All-Fiber Laser with Different 2D and Quasi-2D Perovskite Saturable Absorbers

In recent years, the quasi-2D perovskite material ((PEA) 2 (CsPbBr3) n −1 PbBr 4 ) has exhibited outstanding optoelectronic performance and environmental stability due to its unique structure, presenting a broad range of potential applications. However, structural differences arising from varying values of “ n ” result in distinct nonlinear effects in perovskite materials, which have not been thoroughly investigated to date. We conducted a comparative analysis of the mode-locked characteristics of 2D and n = 3, 4, 5, and 6 quasi-2D perovskite materials within an Erbium-doped fiber laser (EDFL). All materials exhibited excellent saturable absorption effects. Besides, the superior performance of the n = 5 quasi-2D perovskite material, with an SNR of 72.59 dB, performed best in terms of the average power and single pulse energy. The five-layer quasi-2D perovskites offer a suitable bandgap, exciton binding energy, and moderate quantum confinement, leading to effective laser operation. Additionally, the optimal nonlinear absorption, refractive index, and thermal stability contribute to stable and high-power laser performance, while suppressing surface states and interface effects. Experimental results indicate that quasi-2D perovskite materials hold significant potential for applications in the realm of ultrafast optics.