纳微结构发光动力学过程及超快响应

Based on delicate consideration of both the surface plasmonic enhanced light emission effects and the special light modulation from the nano-micro structures, we would fabricate the nano-micro structures embedded with ultrafast light emission materials by the application of femtosecond laser pulse. The ultrafast responsive optoelectronic nano-micro structures are expected to be achieved...The main tasks are as follows: .(1) Sample preparation: with the special profile modulation of laser pulse, we will fabricate different patterns of nano-micro structures combined with the consideration of polarization of the laser beam, the pulse repetition and the density of the femtosecond laser pulse. Furthermore, we will embed the nanometer sized materials such as gold particles and ultrafast multiphotonic lasing materials in the nano-micro strutures to get the composed optical active nano-micro samples. .(2)Ultrafast spectroscopy measurement: the ultrafast light emission behavior will be measured by femtosecond streak camera and the spacial light distribution from the sample will be measured by weak-light micro fluorescence detection system; more difficultly the near field plasmonic enhance light emission behavior should be measured by SNOM combined with pump-probe technique indirectly. .(3)Construction of dynamic model: based on Mie scattering mechanism we have constructed the simulation programm with regarding to spherical nano particels on the crystal substrate,we will continue to construct the simulation model to calculate the light scattering from active nano-micro system, especially from the nanometer scale to micrometer scale to get practical light emission pattern from the sample. Finally, with the output from the simulation we can calculate the space distribution of the ultrafast light emission on the level at geometric optics to satisfy the practical demandings.

为了满足信息高速公路的迅猛发展和互联网信息吞吐量的骤增引起的超快速光信息传输和超高速光信息处理以及超高密度的光信息存储的需求，探索制备超快速响应的光源和超高集成度的光电器件，开拓未来高速超宽带全光网的核心技术，本项目拟在纳微发光研究基础上，寻找新型微纳局域协同超快发光的物理机制，建立超快纳微集成发光动力学模型，结合飞秒激光纳微加工技术和新型纳米材料合成技术，利用近场光谱间接测量联合条纹相机实时瞬态测量的超快发光动力学实验研究手段，实现高速响应的纳微超快发光结构设计、制备和表征。.本项目研究成果将为进一步实现高集成度、超快光通信光源制造提供理论基础和实验支撑，有助于突破传统的载流子注入诱导电致发光器件的时间响应极限，设计具有超快响应速率的发光器件，有希望引发信息和光电集成领域的一系列技术突破。

飞秒激光辐照材料表面诱导形成纳微结构可以直接制备具有接近或低于光波长的周期结构。这种诱导形成的表面结构具有许多新颖有趣的特性，包括表面的彩色化现象，光吸收增加强，表面等离子体激元等。这些现象具有重要的应用价值，可以应用于防伪技术，光探测器制备，太阳能器件研究，照明器件设计以及表面等离子体研究等。同时，新型纳微结构的超快非线性动力学是激光与物质相互作用领域的一个研究重点，其蕴含的丰富的物理意义对新型材料的荧光发光，超短脉冲非线性传输等具有重要的指导意义。. 本项目在材料表面飞秒激光诱导周期表面结构制备的基础上，研究了飞秒激光诱导周期表面结构中红铜表面所形成的彩色化现象。利用平行光垂直入射至已经制备了周期表面条纹结构的红铜表面，在不同的观察角度下观察表面的色彩变化，使用光纤光谱仪对表面的色彩进行光谱表征，与表面结构的周期的计算结果对比，证实了这种色彩是由表面条纹结构的光栅效应所形成的。另外，在甲醇中，我们使用双光子荧光法实时探测了飞秒激光脉冲传输成丝的非线性光动力学过程，并引入ABCD光学系统的理论模型计算了在衍射的作用下高斯型激光脉冲在介质中的传输特性。实验和理论模拟的结果显示：衍射效应在成丝的初始阶段占主导地位，随着传输距离的增加，克尔自聚焦效应逐渐增强并取代衍射效应的主导地位，成为光丝传播的主要机制。