High-order nonlinear optical response of a polymer nanocomposite film incorporating semiconducotor CdSe quantum dots
High-order nonlinear optical response of a polymer nanocomposite film incorporating semiconducotor CdSe quantum dots
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DOI：
10.1364/oe.20.013457
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发表时间：
2012-06-04
期刊：
影响因子：
3.8
通讯作者：
Kawai, Tsuyoshi
中科院分区：
文献类型：
--
作者：
Liu, Xiangming;Adachi, Yusuke;Kawai, Tsuyoshi
我们报告了在我们最近开发的光聚合半导体 CdSe 量子点 (QD)-聚合物纳米复合材料薄膜中观察到的高阶光学非线性，其中 CdSe QD 的各种体积分数高达 0.91 vol.% (3.6 wt.%)。我们使用 532 nm 皮秒激光器以 10 Hz 的重复率提供单个 35 ps 脉冲，进行 Z 扫描和简并多波混频 (DMWM) 测量。使用均匀固化的聚合物纳米复合材料薄膜，我们在闭孔Z扫描测量中观察到三阶和五阶非线性光学效应，发现诱导了可饱和非线性吸收（光致透明）和大的负非线性折射。我们还测量了有效三阶和五阶非线性折射常数对 CdSe QD 体积分数的依赖性。基于Maxwell-Garnett模型，我们估计了CdSe QD的三阶和五阶非线性光学磁化率，并讨论了级联（局部场）效应导致的三阶效应对五阶效应的贡献。 DMWM 也证实了三阶和五阶非线性折射的共存。 (C) 2012年美国光学学会
We report on observation of high-order optical nonlinearities in our recently developed photopolymerizable semiconductor CdSe quantum dot (QD)-polymer nanocomposite films at various volume fractions of CdSe QDs as high as 0.91 vol.% (3.6 wt.%). We performed Z-scan and degenerate multi-wave mixing (DMWM) measurements using a 532-nm picosecond laser delivering single 35 ps pulses at a repetition rate of 10 Hz. Using the uniformly cured polymer nanocomposite films, we observed the third-and fifth-order nonlinear optical effects in closed-aperture Z-scan measurements by which it was found that saturable nonlinear absorption (light-induced transparency) and large negative nonlinear refraction were induced. We also measured dependences of the effective third- and fifth-order nonlinear refraction constants on CdSe QD volume fraction. Based on the Maxwell-Garnett model, we estimated the third-and fifth-order nonlinear optical susceptibilities of CdSe QD and discussed a contribution of the third-order effect to the fifth-order one due to the cascaded (local-field) effect. Coexistence of the third-and fifth-order nonlinear refraction was also confirmed by DMWM. (C) 2012 Optical Society of America