Dispersions of two-photon and three-photon absorption in GaS films from 540 to 1600 nm  

作　　者：Yijie Wang Jinhong Liu Yanqing Ge Erkang Li Lili Zhao Chunhui Lu Yixuan Zhou Xinlong Xu 王艺洁;刘晋红;葛燕青;李二康;赵丽丽;卢春辉;周译玄;徐新龙

机构地区：[1]Shaanxi Joint Laboratory of Graphene,State Key Laboratory Incubation Base of Photoelectric Technology and Functional Materials,International Collaborative Center on Photoelectric Technology and Nano Functional Materials,Institute of Photonics&Photon-Technology,School of Physics,Northwest University,Xi’an 710069,China

出　　处：《Chinese Optics Letters》2025年第1期102-106,共5页中国光学快报(英文版)

基　　金：supported by the National Natural Science Foundation of China(Nos.12261141662 and 12074311);the 2023 Graduate Education Comprehensive Reform Research and Practice Project(No.ZG2023009)。

摘　　要：The development of nonlinear optical materials with strong multiphoton absorption(MPA)is crucial for the design of ultrafast nonlinear optical devices,such as optical limiters and all-optical switchers.In this study,we present the wavelengthdependent coefficients of two-photon absorption(2PA)and three-photon absorption(3PA)in a Ga S film across a broad range of wavelengths from 540 to 1600 nm.The observed dispersions in the 2PA and 3PA coefficients align well with the widely used two-band approximation model applied to direct bandgap semiconductors.Notably,the Ga S film exhibits exceptional MPA properties with a maximum 2PA coefficient of 19.89 cm/GW at 620 nm and a maximum 3PA coefficient of4.88 cm^(3)/GW2at 1500 nm.The Ga S film surpasses those found in traditional wide-bandgap semiconductors like β-Ga_(2)O_(3),Ga N,Zn O,and Zn S while remaining comparable to monolayer Mo S_(2),Cs Pb Br_(3),and(C_(4)H_(9)NH_(3))_(2)Pb Br_(4) perovskites.By employing a simplified two-energy-level model analysis,our results indicate that these large MPA coefficients are primarily determined by the remarkable absorption cross sections,which are approximately 4.82×10^(-52)·cm^(4)·s·photon-1at 620 nm for 2PAand 8.17×10^(-80)·cm^(6)·s^(2)·photon^(-2)at 1500 nm for 3PA.Our findings demonstrate significant potential for utilizing Ga S films in nonlinear optical applications.

关 键 词：GaS film multiphoton absorption two-photon absorption three-photon absorption DISPERSION 

分 类 号：O469[理学—凝聚态物理]