[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？ (-yl|NFBw  
以下是我的ＡＳＡＰ代码，可以拷贝运行一下。 '%iPVHK7  
=C7 khE  
SYSTEM NEW $K}. +`vVO  
RESET gvavs+H%  
;6;H*Y0,|E  
UNITS MM s'I)A^i+  
WAVELENGTHS 3.7 UM EYzg%\HH  
>=,uau7  
COATING PROPERTIES x!7yU_ls`  
  1 0 'REFLECT' m9$:9yRm  
  0 0 'ABSORB' xp \S2@<  
?r_kyuU  
PARABASAL 4 LgqGVh3\s  
BEAMS COHERENT DIFFRACT B&KL2&Z~Pq  
WIDTHS 1.6 S\C*iGeqJ  
eQN.sl5  
A=1   +Ghi}v  
N=32   /MTf0^9  
L=(N)*(A)   ~hX-u8Ul'N  
D1=0.625E-3     dDcZ!rRaL@  
D2=(N)*(D1) 3}Xc71|v  
!! 微阶梯镜======================= sa-9$},z4  
$DO -16 15 1 O12Q8Oj!0  
{SURFACE 5N/Lk>p1u
 
   PLANE Z 0 RECTANGLE (A)/2 (L)/2 rGwIcx(%  
OBJECT 'MIRROR2_?' 0irr7Y  
   INTERFACE COATING REFLECT AIR AIR   *:"^[Ckc  
   SHIFT X (A)*?+(A)/2 I<\ '%  
   SHIFT Z (D2)*?   _^!vCa7f  
}   jZ9[=?   
GROUP MIRROR2_? j'rS&BIG  
  SHIFT Z (L)
K'b*A$5o  
  ROTATE X -90 0 0   4SVW/Zl.?  
!! DETECTOR======================   )/t6" "  
SURFACE |"7Pv skT  
  PLANE Y -(2*L) RECTANGLE (L)/2 (L)/2 7nE"F!d+0  
OBJECT 'DETECTOR' 5
D`26dB2  
  INTERFACE COATING ABSORB AIR AIR   ^$?qT60%d|  
!! SOURCE ======================= !c(QSf502  
GRID RECT Y -(L) -(L)/2 (L)/2 -(L)/2 (L)/2 (256) (256) Ej
(2w Q  
  SOURCE DIR 0 1 0 Q+[ .Y&  
!! !!TRACE PLOT========================= yXfMzG  
!!WINDOW Y Z 6SEltm(  
!!PLOT FACETS 5 5 !!OVERLAY ?[1SiJT  
TRACE!! PLOT "ED8z|]j  
!!$VIEW   RI.2F*|  
BSUPS+@+  
CONSIDER ONLY DETECTOR !!CONSIDER ONLY DUMY POd/+e9d  
WINDOW X -(L)/2 (L)/2 Z -(L)/2 (L)/2   R{}qK r  
PIXELS (256) R 1zC.m  
SPREAD NORMAL A|RR]CFJ  
DISPLAY p8>%Mflf  
!!  FORM 0.5 4br6$  
  PICTURE ohZx03  
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.