哈工大信息光学Chapter5-1.pdf

幻 灯 片 Chapter 5 1 Wave-Optics Analysis of Coherent Optical Systems Weimin Sun College of Science Harbin Engineering University 幻 Suffer：遭受，经历 灯 A thin lens as a phase transformation 片 y 2 Let the maximum thickness of the lens (on its axis) be , and let the thickness 0 at coordinate (x,y) be (x,y ). x Then the total phase delay suffered by the wave at coordinate (x,y) in passing through the lens may be written f ( x, y ) kn (x , y ) k [ 0 (x , y )] (x,y ) where n is the refractive index of the lens material, kn(x,y ) is the phase delay 0 introduced by the lens, and k[ -(x,y)] 0 is the phase delay introduced by the remaining region of free space between the two planes . 幻 Equivalently：等效地 灯 片 3 n Equivalently, the lens may be represented by a multiplicative phase transformation of the form t (x , y) exp(jk ) exp[jk (n 1)(x ,y )] l 0 n The complex field U ’(x,y) across a plane immediately