CdS纳米粒子的四波混频研究  

Degenerate Four Wave Mixing Study of CdS Nanoparticles

作　　者：张宇[1] 傅德刚[1] 汪昕[1] 刘举正[1] 顾宁[1] 陆祖宏[1] 王刚[2] 崔一平[2] 

机构地区：[1]国家分子与生物分子电子学实验室化学化工系,东南大学南京210096 [2]国家分子与生物分子电子学实验室电子工程系,东南大学南京210096

出　　处：《测试技术学报》2000年第4期226-230,共5页Journal of Test and Measurement Technology

摘　　要：目的　研究表面化学修饰对纳料粒子光学非线性的影响 .方法　采用简并四波混频 (DFWM)方法测量了表面用 2 ,2 ' -联吡啶 (bpy)进行化学修饰的 Cd S纳米粒子 (记为Cd S/ bpy)有机深胶的三阶非线性光学响应 ,并考虑一个双光子吸收的修正因子 ,用最小二乘法对实验结果进行了拟合 .结果　求得每个 Cd S/ bpy粒子的三阶超极化率的实部γIR=-0 .42× 1 0 -2 7esu,虚部 γ1 I=2 .0 2× 1 0 -2 7esu.结论　较大的虚部表明双光子吸收导致的共振增强作用对 DFWM信号有重要贡献 .另外 ,还用表面效应解释了表面修饰 Cd S纳米粒子相对于裸的 Cd S纳料粒子 (水溶胶 )Aim\ To investigate the influence of surface chemical modification on the optical nonlinearities of nanoparticles. Methods\ The third order nonlinear optical response of surface modified CdS nanoparticles with 2,2\+' bipyridine (named as CdS/bpy) in organic solvent was measured via a Degenerate Four Wave Mixing (DFWM) technique. Considering a correction factor to two photon absorption, the experimental data was fit by the least square method. Results\ The results show that the real part of third order hypersusceptibility is -0.42×10\+\{-27\} esu and the imaginary part is 2.02×10\+\{-27\} esu. Conclusion\ The larger imaginary part shows that two photon absorption induced resonance enhancement plays an important role in the contribution to DFWM signal. For the surface modified CdS nanoparticles, the third order nonlinear optical response is enhanced as compared with bare CdS nanoparticles in water, interpreted in terms of surface effects.

关 键 词：三阶光学非线性 四波混频 CDS纳米粒子 

分 类 号：TB383[一般工业技术—材料科学与工程] O437[机械工程—光学工程]