-光学人物试题.ppt

光信息科学与技术专业 光 学 主讲教师: 郑耀辉 (光电研究所, 量子光学与光量子器件国家重点实验室) Email: yhzheng@sxu.edu.cn 电话：7113885 办公地址：量子光学科研楼323 Introduction 古老而充满生机 BC600 ~ 至今，激光的产生、多学科交叉。 平常又不寻常 随处可见、又难以说清楚！ 简单又复杂 常见现象、简单仪器、复杂设计。 色散、像差、双折射等。 非线性、非经典(单光子)、光的测量。 Light:wave and/or particle ? Young and Fresnel Faraday and Maxwell Einstein 1905 Reaction to Einstein’s paper 1921: Nobel prize to Einstein for photoelectric effect Quantum Mechanics Situation in the 50-70s The hero of the story: the beamplitter The crucial experiment: Kimble, Dagenais, Mandel 1977 Conclusion: is light a wave and/or a particle ? light can look like classical wave Light can look like a classical particle Light can look like nothing classical What is the nature of light ? Situation in the 50-70s 電磁波示意圖  光学课主要内容 几何光学及光度学 几何光学基本定律 惠更斯原理，费马原理 共轴球面组成像，薄透镜成像，理想光具组理论 光学仪器，光度学基本概念 波动光学 光的干涉 光的衍射 光的偏振 傅立叶(Fourier)光学简介 量子特性简介 玻尔原子模型与爱因斯坦辐射理论，粒子反转与光放大 激光原理与进展 量子光学及量子信息 The semi-classical approach explains most phenomena involving light. the photoelectric effect can be explained without photons ? quantum jump ? of electron, not arrival of a photon MUST WE WITHDRAW EINSTEIN’S NOBEL PRIZE ? Semi-classical approach of matter–light interaction Quantization of light only useful to calculate subtle properties of matter Semiclassical approach (using classical electromagnetic wave) allows physicists to calculate all properties of fields No direct evidence of the existence of the photon as it freely propagates A beamspliiter divides a wave in two parts, but cannot divide a photon in two parts ! (1) (2) (2) (1) (Newton was aware of the problem) (1) (2) Coincidence counter Semi classical theory: Full quantum theory: coincidence never occurs coincidence may randomly occur Single Photon Source Single excited atom Experiment with a very weak light source: (1) (2) Coincidence counter Coincidences measured ! Compatible with random events ! A weak light source is not a single photon source There is a non-zero probability to have two p