基于光子时间间隔统计的激光相干频率分析新模型

项目名称： 基于光子时间间隔统计的激光相干频率分析新模型

项目编号： No.61205143

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 信息四处

项目作者： 张合勇

作者单位： 中国科学院长春光学精密机械与物理研究所

项目金额： 28万元

中文摘要： 传统激光相干探测依靠增加本振光束的功率来提高探测灵敏度，而实际研究中发现较强的本振光会带来较大散粒噪声。因此，该项目旨在从光子计数角度分析弱激光相干探测中存在的上述问题。具体从以下2方面展开研究：第一，采用多像素光子计数器(MPPC)作为接收探测器，将激光相干探测所需的本振光和信号光分别看作相干光场和赝热光场进行统计分析，主要分析参数包括光场热模数、Fano因子、对称参数，通过对上述两种光场分析获得混合光场统计特性，为分析目标反射特性及干涉信号频率提取提供数据支撑。第二，在混合光场干涉频率提取方式上，采用全新的光子时间间隔统计方式，建立光场干涉频率分析新模型，在其概率密度分布函数曲线上提取激光干涉信号频率，并进一步估计信号光和本振光的混合效率。其中所采用光子计数率远小于干涉信号频率值，即以较小的光子计数率探测较高干涉频率，理论分析表明，该方法能够突破MPPC死亡时间所带来的探测器带宽限制。

中文关键词： 统计光学；激光相干；光子时间间隔；概率密度函数；死亡时间

英文摘要： The enhancement of detection sensitivity for traditionallaser heterodyne detection is mainly based on increasing the power of local oscillator,in fact,the higher the local oscillator, the intenser the short spot noise. Therefore,this scientific project will mainly solve the problem of large noise in coherent detection founded on photon counting.The detailed description of the research contained the following two aspects: Firstly, the local oscillator and the echo signal in coherent detection can be regarded as coherent and pseudo-thermal light field respectively. The Multi-Pixel Photon Counter(MPPC) can be used for photon statistics,the primary parameter which can be acquired from the statistic are as follows: the number of thermal modes for the light field, the Fano factor,symmetry parameter.The statistacal property of the mixed light field can be gained through the methods above.thereby, the research before will be the groundwork for the target's reflection characteristic and the frequency extraction of coherent detection.Secondly,the novel mode for the frequency extaction has been established through the statistic of arrived photon time interval,this new method is absolutely different from the traditional way of frequency analysis based on FFT(Fast Fourier Transform).The frequency extraction of the new met

英文关键词： Statistics optics；laser coherent；photon time interval；probability density function；dead time