基于飞秒时间门选通信号光的瞬态显微成像技术

项目名称： 基于飞秒时间门选通信号光的瞬态显微成像技术

项目编号： No.61308036

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 无线电电子学、电信技术

项目作者： 佟俊仪

作者单位： 西安理工大学

项目金额： 28万元

中文摘要： 飞秒时间门选通成像技术具有很高的时间分辨率和极强的抑制散射光的能力，因而适于观测高密度散射介质内目标物体或结构的动态过程，在物理和材料科学领域中具有重要的应用价值。然而，目前该技术成像空间分辨率仅为数十微米量级，无法测量飞秒激光烧蚀靶材等微区内微结构改变的动态过程。为此，本项目提出一种基于飞秒时间门选通信号光、抑制散射光的显微成像技术，使飞秒时间门选通成像技术的应用范围扩展至能够观测微区内超快动力学过程。主要研究内容包括：通过调控飞秒时域光克尔门中相干效应与克尔效应之间的竞争，抑制相干效应对信号光的干扰，提高成像信噪比；通过将时间门选通与空间频谱滤波有机结合，提高成像信噪比；研究飞秒脉冲在散射介质中传输的时空演化特性；研制适于散射介质微区内动态目标观测的飞秒时间门选通显微成像系统，成像系统时间分辨率优于200fs，空间分辨率优于10μm，散射介质最大光学密度大于12。

中文关键词： 飞秒激光；瞬态显微成像；时间门选通；散射介质；

英文摘要： Femtosecond time-gated imaging technique with optic Kerr gate has a high temporal-spatial resolution and the ability of eliminating the diffusive photons, so it has very important significantances for the observations of the dynamics of the targets embedded in turbid media in the studies of physics and materials. Up to now, however, the spatial resolution for this technique is only dozens of microns, and can not be applied to the observations of the formation dynamics of the microstructures in the femtosecond laser micromachining. Therefore, in this project we propose a microscopic imaging technique based on optical Kerr gate, in which the image-bearing photons can be selected efficiently and the diffusive photons can be eliminated, in order to extend the ability of the femtosecond time-gated imaging technique to observing the dynamic behaviors of the targets inside the microdomain of turbid media.The study includes: 1) Eliminating the influence of coherent effect and improving the signal-to-noise ratio by controlling the competition between the coherent effect and optical Kerr effect in femtosecond optic Kerr gate experiments; 2）Improving the signal-to-noise ratio of the images by combining the time-gated imaging technique and spatial frequency filtering technique; 3)Investigate the temporal and spatial propa

英文关键词： Femtosecond laser；transient microscopic imaging；time gating；turbid media；