圆偏振光的产生、测量与自旋偏振电子的光注入

Generation and Measurement of Circularly Polarized Light and Optical Injection of Spin-polarized Electrons

理论上给出了线偏振光通过波片产生的椭圆偏振光的圆偏振度与方位角和相位延迟量的关系。结果表明,圆偏振度对方位角的变化更灵敏,在保持圆偏振度不变条件下,每提高方位角精度一度,则可降低相位延迟精度至少两度,这将改变人们重视相位延迟而轻视方位角精度的通常做法,降低1 4波片的加工难度和造价。还给出了宽带光谱分布和波片相位延迟色散对圆偏振度影响的解析解。发展了一种圆偏振度和波片相位延迟实验测量的简单方法。利用这种方法实验测试了Newport公司生产的1 4波片的相位延迟。

The dependence of the degree of circular polarization (DCP) of an elliptically polarized light, produced by linearly polarized light through a waveplate on the azimuth angle and phase retardation of the waveplate, is given theoretically. It shows that DCP is more sensitive to the azimuth angle, and the accuracy of phase retardation may be decreased by at least 2° as the accuracy of the azimuth angle is increased by 1° under the condition of constant DCP. This will change the conventional viewpoint to emphasize on the accuracy of the phase retardation and neglect that of the azimuth angle, and reduce the difficulties and expenses of waveplates in fabrication. The effects of the spectral distribution of light and the dispersion of the phase retardation on DCP are also considered. A simple method to measure DCP and phase retardation of a waveplate is developed and is used to measure the phase retardation of the 1/4 waveplate manufactured by Newport Company, Inc.