Broadband nonlinear refraction transients in C-doped GaN based on absorption spectroscopy  

作　　者：FANGYUAN SHI YUNFEI LV ZHANPENG CHEN XINGZHI WU ZHENGGUO XIAO ZHONGGUO LI QUANYING WU YINGLIN SONG YU FANG 

机构地区：[1]Key Laboratory of Efficient Low-carbon Energy Conversion and Utilization of Jiangsu Provincial Higher Education Institutions,School of Physical Science and Technology,Suzhou University of Science and Technology,Suzhou 215009,China [2]Department of Physics and Electronic Engineering,Tongren University,Tongren 554300,China [3]School of Electronic and Information Engineering,Changshu Institute of Technology,Changshu 215500,China [4]School of Physical Science and Technology,Soochow University,Suzhou 215006,China

出　　处：《Photonics Research》2024年第10期2334-2343,共10页光子学研究（英文版）

基　　金：National Natural Science Foundation of China(11704273,12374300);Natural Science Foundation of Jiangsu Province(BK20221384);Jiangsu Key Disciplines of the Fourteenth Five-Year Plan(2021135);Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX22_3267);Science and Technology Innovation Team of Guizhou Education Department([2023]094);Science and Technology Foundation of Guizhou Province(ZK[2023]049)。

摘　　要：Optical nonlinear response and its dynamics of wide-bandgap materials are key to realizing integrated nonlinear photonics and photonic circuit applications.However,those applications are severely limited by the unavailability of both dispersion and dynamics of nonlinear refraction(NLR)via conventional measurements.In this work,the broadband NLR dynamics with extremely high sensitivity(λ∕1000)can be obtained from absorption spectroscopy in GaN:C using the refraction-related interference model.Both the absorption and refraction kinetics are found to be significantly modulated by the C-related defects.Especially,we demonstrate that the refractive index changeΔn of GaN:C is negative and can be used to realize all-optical switching applications owing to the large NLR and ultrafast switching time.The NLR under different non-equilibrium carrier distributions originates from the capture of electrons by CN defect state,while the absorption modulation originates from the excitation of tri-carbon defects.We believe that this work provides a better understanding of the GaN:C nonlinear properties and an effective solution to broadband NLR dynamics of transparent thin films or heterostructure materials.

关 键 词：REFRACTION ABSORPTION NONLINEAR 

分 类 号：O433[机械工程—光学工程]