透镜介质中单光子态光动量的实验研究

Based on a series of experiments, we study the momentum of light in transparent medium in this project. More than a century ago, Minkowski and Abraham put forward two completely different theory of the momentum of light almost at the same time. Minkowski's formula is nE/c, and Abraham's formula is E/(nc). Here, N, E and c are the refractive index of transparent medium, light energy and the speed of light in the vacuum, respectively. In order to clarify the two different light momentum, theorists have put forward different theories and had a fierce debate, but never been able to get a precise and satisfactory answer since it is extremely difficult to test by experiments. So far, a few experiments have been reported, but they still remain some questions. In addition, the momentum of light also has very important applications in many aspects, such as light machinery and light-induced nuclear fusion. Therefore the study of the mementum of light in transparent medium is important in science and practical application. In this project, we intend to use the experiments of water pressure, oil film pressure, cantilever beam fiber and optical waveguide pressure to study the light momentum in transparent medium further. These experiments are more simple, intuitive, and effective. We expect to get favorable results, in order to judge Abraham momentum and Minkowski momentum.

该项目主要是对透明介质中光动量问题进行实验研究。一个多世纪以前，Minkowski和Abraham几乎同时提出两个完全不同的关于介质中光动量的理论：Minkowski公式是nE/c，Abraham公式是E/(nc)。这里n、E和c分别是透明介质的折射率、光波能量和真空光速。为了澄清这两个不同的光动量，理论学家们提出了许多理论，并展开激烈的争论。但到目前为止仍无法得到一个确切和令人满意的答案。相当程度上说，这是因为没有很好的实验支持。对光动量的实验检验极端困难，现已公开发表的实验工作寥寥无几，尚缺乏令人信服的实验结论。此外，光与物质之间的动量交换是光力学的核心，光动量在光机械、光诱导核聚变生物医学、纳米工程、光操控等方面有十分重要的应用，所以对透明介质中光动量的研究，尤其是实验验证就很有科学和应用意义。本项目拟利用水面光压实验、油膜光压实验、悬臂梁光纤光压实验和液芯光波导光压实验这四类更为简单、直观、有效的实验方案对透明介质中光动量问题进行进一步的研究，期望得到有利的实验结果，判断Abraham光动量形式和Minkowski光动量形式的正确性。

Minkowski和Abraham关于介质中光动量的理论被持续争议一个多世纪，但至今没有一个确切和令人满意的答案。一定程度上讲，这是因为缺乏令人信服的实验支撑。此外，光与物质之间的动量交换是光力学的核心，在光机械、生物医学、纳米工程等方面有十分重要的应用，所以对透明介质中光动量的研究具有很高的学术价值和应用价值。首先，本项目通过液面光压实验和悬臂梁光纤光压实验直接测量介质中光动量，解决以往无法直接观察光致界面形变的难题。液面光压实验结果显示非聚焦532nm连续入射光可导致液体表面凸起，说明入射光在界面处的光动量改变对液面具有拉力的作用，这只能由Abraham光动量解释。悬臂梁光纤光压实验综合考虑悬臂梁光纤的绕度和光动量改变，结果依然符合Abraham光动量。其次，项目利用光动量产生的力学效应，分析得到矢量光场光动量改变所引起的散射力对微粒具有推力作用，结果满足Abraham光动量形式；并且给出同时产生不同波长矢量光场的实验方案，构建矢量光场微纳光操控的实验装置，为研究光散射力的力学效应及光动量测量提供了理论和实验基础。最后，将光动量与光子角动量相结合，提出两种检测光子角动量的实验方案，为间接探测介质中光子动量提供新的实验思路。本项目的一系列研究为解决介质中光子动量这一争议性物理问题提供了一定实验素材。