Author Affiliations
Abstract
1 State Key Laboratory of Luminescent Materials and Devices (SKLLMD), South China University of Technology, Guangzhou 510640, China
2 Department of Chemistry, National University of Singapore, 117543, Singapore
3 NUSNNI-NanoCore, National University of Singapore, 117576, Singapore
4 e-mail: msxfjiang@scut.edu.cn
We report a simple solution-processed method for the fabrication of low-cost, flexible optical limiting materials based on graphene oxide (GO) impregnated polyvinyl alcohol (PVA) sheets. Such GO–PVA composite sheets display highly efficient broadband optical limiting activities for femtosecond laser pulses at 400, 800, and 1400 nm with very low limiting thresholds. Femtosecond pump–probe measurement results revealed that nonlinear absorption played an important role for the observed optical limiting activities. High flexibility and efficient optical limiting activities of these materials allow these composite sheets to be attached to nonplanar optical sensors in order to protect them from light-induced damage.
Thin films, optical properties Nonlinear optical materials Ultrafast nonlinear optics Spectroscopy, time-resolved Photonics Research
2015, 3(3): 03000A87
1 中山大学 光电材料与技术国家重点实验室， 广东 广州510275
2 中山大学 化学与化工学院, 广东 广州510275
室温下采用640 nm的飞秒脉冲激光泵浦ZnO纳米针得到双光子诱导的光致发光谱。结合单光子下的研究结果，实验分析了双光子泵浦下样品随着受激能量增强产生的三种紫外发射行为并归结为自由激子自发辐射，激子-激子散射和电子空穴等离子体复合。双光子泵浦下ZnO纳米针的受激阈值是4.82 GW/cm2，远小于其他ZnO微纳材料的双光子阈值(TW/cm2)。结果表明：这种新型的ZnO纳米针结构能更有效地产生双光子激射，这在纳米激光器方面将会有很大的应用前景。
氧化锌 纳米针 受激发射 光致发光 ZnO nanoneedle stimulated emission photoluminescence
