Arnaud J A, Kogelnik H
Appl Opt. 1969 Aug 1;8(8):1687-93. doi: 10.1364/AO.8.001687.
This paper considers the propagation and diffraction of coherent light beams through nonorthogonal optical systems such as sequences of astigmatic lenses oriented at oblique angles to each other. The fundamental (gaussian) mode has elliptical light spots in each beam cross section and ellipsoidal (or hyperboloidal) wavefronts near the axis. It is found that the orientation of the light spot differs from that of the wavefront, and changes continuously by as much as pi radians as the beam propagates through free space. A theory of these general astigmatic beams is given and simple experimental observations are described. The coupling factor between two such beams is also given.
本文研究了相干光束通过非正交光学系统（如彼此成斜角排列的像散透镜序列）的传播和衍射。基模（高斯模）在每个光束横截面上有椭圆形光斑，在轴附近有椭球面（或双曲面）波前。研究发现，光斑的取向与波前的取向不同，并且当光束在自由空间中传播时，光斑取向会连续变化多达π弧度。给出了这些一般像散光束的理论，并描述了简单的实验观察结果。还给出了两个这样的光束之间的耦合系数。
