三孔干涉条件下部分相干电磁光束的偏振特性

Polarization Properties of Partially Coherent Electromagnetic Beams in Three Points′ Interference Pattern

推导了三孔干涉条件下的交叉谱密度矩阵,研究了该条件下部分相干光偏振特性的变化情况。比较了x、y方向场分量不相关和相关的情况,并与同样条件下双孔干涉的偏振度变化进行了对比。研究表明,偏振度在观察面上是振荡变化的,离中心越远振荡越剧烈;不同位置的偏振度传输足够长的距离后都将趋于稳定,其稳定值与参量Bxy和δxy有关,且离中心越远其偏振度达到稳定的传输距离越长;轴上偏振度与三孔的初始相干度是密切相关的。特别指出,当x、y方向场分量相关时,对应点偏振度的值远远大于其不相关的情况。

The cross-spectral density matrix in three points＇ interference pattern is derived, and the variation of polarization properties of partially coherent beams under this condition is given. A comparation between the cases of unrelated and related field components of x-direction and y-direction is studied, and compared with two points＇ interference pattern in the same conditions. It is shown that the degree of polarization is oscillating in the observation plane. The farther away from the center, the more intense the oscillation is. The degree of polarization at different positions tends to the stable value after a long-propagation distance, which is related to the parameters of B~ and ~. The farther away from the center, the longer-propagation distance that the degree of polarization tends to be stable. The degree of polarization on the axes is closely related to the initial degree of coherence of three points. In particular, when field components of x-direction and y-direction are related, the degree of polarization at the corresponding point is much larger than the case of unrelated field components.