【作者】 刘启明； 赵修建； 干福熹； 米君； 钱士雄；

【Author】 Liu Qiming Zhao Xiujian Key Laboratory of Silicate Materials Science and Engneering (Wuhan University of Technology),Ministry of Education,Hubei Wuhan 430070 Fuxi Gan Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,RO.Box 800-211,Shanghai,201800,R R.China School of Information Sciences and Engineering,Fudan University,Shanghai 200433,RR.China Jun Mi Shixiong Qian Department of Physics,Fudan University,Shanghai 200433,RR.China

【机构】 武汉理工大学硅酸盐材料工程教育部重点实验室； 中国科学院上海光学精密机械研究所； 复旦大学物理系；

【摘要】 运用X 射线衍射分析（XRD）、红外光谱分析（IR）和透射光谱分析,研究了Ge₂₀As₂₅Se₅₅非晶半导体薄膜经514.5nm 波长的氩离子激光辐照后的结构及性能变化。实验结果表明,经热处理和激光辐照后,在薄膜中观察到光致漂白效应,即薄膜的光学吸收边均移向短波长处（绿移）,并且随着辐照激光强度和辐照时间的增大而增大。利用超外差—光克尔效应法测得薄膜的三阶非线性实部和虚部值分别为6.6×10^-12 esu 和-2.4x10^-12 esu,其非线性响应时间小于200fS。更多还原

【Abstract】 The changes of structure in Ge_20As₂₅Se₅₅ amorphous semiconductor films by light illumination from Ar ion laser were studied with the XRD,IR and transmission spectra analysis.It was indicated that the optical absorption edges of films shifted to shorter wavelength according tolight illumination.The magnitude of shift increased with the increase of the intensity ofillumination light and the illumination time.By sides,Ge₂₀As₂₅Se₅₅films were studiedexperimentally by the method of the femtosecond optical heterodyne detection of optical Kerreffect.The real and imaginary parts of complex third-order optical nonlinearity was effectivelyseparated and their values and signs could be also determined,which were 6.6×10^-12 esu and-2.4×10^-12 esu,respectively.Amorphous Ge₂₀As₂₅Se₅₅ films showed a very fast response in therange of 200 fs under ultrafast excitation.更多还原