[求助]用ASAP高斯光束分解的方法遇到的问题 [复制链接]

各位光学专业的大神，我最近在用ASAP对微阶梯反射镜（如附图）进行模拟。一束单色平行光垂直入射到微阶梯反射镜上，用探测器接收反射光。如图，理论上在探测器上应该也是均匀的光场，但是用ＡＳＡＰ的高斯光束分解模拟得到的结果却如图所示。这是为什么呢？  9-Xr  
以下是我的ＡＳＡＰ代码，可以拷贝运行一下。 d-B,)$zE  
knRs{1}Pw{  
SYSTEM NEW dz)(~@tgz  
RESET !InC8+be  
8LGNV&Edg  
UNITS MM CD)JCv  
WAVELENGTHS 3.7 UM Uq(fk9`6  
}i9VV+L#1  
COATING PROPERTIES Gg{M  
  1 0 'REFLECT' +\25ynM

 
  0 0 'ABSORB' nZ#0L`@"Y  
*NoixV1>  
PARABASAL 4 h:<?)g~U  
BEAMS COHERENT DIFFRACT .\"8H1I\T  
WIDTHS 1.6 Url8&.pw  
= Tq\Ag:  
A=1   &>vfm9  
N=32   1raq;^e9  
L=(N)*(A)   "?s  
D1=0.625E-3     mN1n/LNi  
D2=(N)*(D1) bA/'IF+  
!! 微阶梯镜======================= +
sx$%N  
$DO -16 15 1 i: VMCNH  
{SURFACE e9rgJJ  
   PLANE Z 0 RECTANGLE (A)/2 (L)/2 A%.ZesjAx  
OBJECT 'MIRROR2_?' dg@'5.ApPu  
   INTERFACE COATING REFLECT AIR AIR   VH<-||X/4  
   SHIFT X (A)*?+(A)/2 ;~(yv|f6  
   SHIFT Z (D2)*?   noO#o+ Jg#  
}   '_FxxLAO  
GROUP MIRROR2_? J(Zz^$8]<?  
  SHIFT Z (L) $[+)N~  
  ROTATE X -90 0 0   p4z thdN[  
!! DETECTOR======================   iB5'mb*
 
SURFACE Gw+pjSJL`  
  PLANE Y -(2*L) RECTANGLE (L)/2 (L)/2 h|OWtf4  
OBJECT 'DETECTOR' \ 9#X]H  
  INTERFACE COATING ABSORB AIR AIR   N
)  
!! SOURCE ======================= y*#+:D]o*  
GRID RECT Y -(L) -(L)/2 (L)/2 -(L)/2 (L)/2 (256) (256) #E4|@}30`  
  SOURCE DIR 0 1 0 mD;ioaE  
!! !!TRACE PLOT========================= REJHh\:.77  
!!WINDOW Y Z 1i@a? 27
|  
!!PLOT FACETS 5 5 !!OVERLAY 3% O[W  
TRACE!! PLOT b-YmS=*  
!!$VIEW   -BEd7@?A  
? w@)3Z=u  
CONSIDER ONLY DETECTOR !!CONSIDER ONLY DUMY z(1`Iy M  
WINDOW X -(L)/2 (L)/2 Z -(L)/2 (L)/2   {ukQBu#}<  
PIXELS (256) !3 zN [@w,  
SPREAD NORMAL _tpOVw4I  
DISPLAY =JN{j2xY  
!!  FORM 0.5 lec3rv0)  
  PICTURE 96<0=   
RETURN

有谁知道吗？急啊。

好吧，过了这么久都没人回。

Since you use the coherence switch, the edge might diffract the gaussian beam and those diffracted beams interfer with your other beams to give out the interference pattern.