部分相干径向偏振光束传输中相干性研究

根据广义惠更斯理论及相干偏振统一理论, 研究部分相干径向偏振光束在自由空间中传输时, 不同参考点处复相干度随传输距离的变化规律. 研究表明, 部分相干径向偏振光束在自由空间中传输, 不同参考点处, 复相干度模值随距离的变化规律有所差别. 当参考点位于原点时, 随着传输距离增大, μ_xx模值及μ_xy模值分布形式不变, 分布范围增大; 当参考点位于x轴上时, μ_xx模值由单峰值向三峰两谷对称形式演化, μ_xy模值由单侧两峰向四峰四谷对称形式演化, 完成演化所需传输距离与参考点距离x轴中心的远近有关, 参考点距离x轴中心越近, 完成演化所需的传输距离越短; 当参考点位于y轴时, 随着距离增大, μ_xx模值分布形式不变, 分布范围增大, μ_xy模值由上侧两峰向四峰四谷对称形式演化, 演化所需传输距离与参考点距y轴中心远近有关, 参考点距y轴中心越近, 完成演化所需的传输距离越短; 当参考点位于其他位置时(非特殊位置), μ_xx模值及μ_xy 模值分布规律, 遵从各自参考点在x轴, y轴上的分布规律的结合即参考点位于其他位置时, μ_xx模值及μ_xy模值分别随距离变化逐渐演化成三峰结构、四峰结构.

Research on the coherence of partially coherent radially polarized beam during propagation

Based on the generalized Huygens theory and the unified theory of coherence and polarization, study is made on the module value of complex degree of coherence of partially coherent radially polarized beam (PCRPB) which changes with transmission distance at different reference point. Results show that the module value distribution of the complex degree changing with the transmission distance is different for different reference point while PCRPB propagates in a free space. When the reference point is at the origin, with the increase of the transmission distance, μ_xx and μ_xy hold a symmetric distribution, and the distribution range increases. When the reference point is confined on the x-axis, μ_xx changes from single peak to three peaks, and the two valleys lie symmetrically; and μ_xy changes from two peaks to four peaks, and the four valleys lie symmetrically. The transmission distance of the evolution is related to the distance between the reference point and the origin: the closer the distance between the reference point and the origin, the shorter the transmission distance is needed to achieve the evolution process. When the reference point lies on the y-axis, μ_xx holds a symmetric distribution, its distribution range increases, and μ_xy changes from two peak values to four peaks and four valleys which are in symmetric form. The transmission distance is related to the spacing between the reference point and the origin, the closer the distance between the reference point and the origin: the shorter the transmission is needed to achieve the evolution process. In addition, when the reference point lies at other positions on the observation plane, the module value distribution of μ_xx and μ_xy is obtained by combining the distribution rules of reference point at x-axis and y-axis: i.e., when the reference point lies at other positions of the observation plane, the module values μ_xx and μ_xy can be composed of three peaks and four peaks with the increase of transmission distance, respectively.