非线性自成像效应及其调控研究

项目名称： 非线性自成像效应及其调控研究

项目编号： No.11274162

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 张勇

作者单位： 南京大学

项目金额： 93万元

中文摘要： Talbot效应,又叫自成像效应,是指光照射到一个具有周期结构的物体时会在后面有限距离处出现物体自身的像。这是一种近场无透镜成像技术。Talbot 效应在实践中已经被广泛地应用于光刻、光学精密测量、光开关等众多领域。在基础研究中，这一概念也被拓展到了量子光学、波色-爱因斯坦凝聚等领域。申请人在国际上率先把非线性光学引入进来,在具有周期非线性系数分布的非线性光子晶体中实现了二次谐波Talbot效应，在成像质量方面有较大的提高。在前期研究基础上，本项目将研究非线性光子晶体和非线性光波导阵列这两个材料体系中的非线性Talbot效应，利用微结构材料设计、电光效应等手段实现对非线性Talbot效应的人工调控，同时探讨基于双光栅Talbot干涉仪的微结构成像技术。通过本课题的研究，可进一步开拓非线性Talbot效应在成像、无损探测、光阵列、光通讯、光计算等领域的应用。

中文关键词： 自成像效应；非线性光子晶体；准相位匹配；；

英文摘要： The Talbot effect, a near-field diffraction phenomenon of periodic object, was first observed by H. F. Talbot in 1836 when he illuminated a diffraction grating with a white light source. Recent progresses on fundamental Talbot effect are made with, for example, single photons and entangled photon pairs, waveguide arrays, metamaterials, and electromagnetically induced grating. The effect is more than just an optical curiosity for physicists, and has led to a variety of applications, such as photolithography, optical testing, optical metrology, and array illuminator. The extension to X-ray and terahertz (THz) waves through Talbot interferometers is particularly useful because of the lack of efficient optics for these wavelengths. Recently, we reported a novel nonlinear Talbot effect in periodically poled LiTaO3 (PPLT) crystals, where the self-imaging is formed by the generated second-harmonic (SH) waves instead of the fundamental input beam. The prerequisite condition to realize the effect is to have a periodic SH pattern, which is fulfilled by the periodic distribution of second-order nonlinear coefficients in the PPLT crystals. Besides no real grating used in the experiment, spatial resolution improvement by a factor of 2, due to frequency doubling, is powerful to high-resolution imaging, compared with the simp

英文关键词： Talbot self-imaging；nonlinear photonic crystal；quasi-phase matching；；