[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？ b$b;^nly  
以下是我的ＡＳＡＰ代码，可以拷贝运行一下。 Y!L-5|G  
MKfK9>a  
SYSTEM NEW $9X+dvu*  
RESET GTR*3,rw  
|*c1S -#  
UNITS MM !'N@ZZ  
WAVELENGTHS 3.7 UM "K(cDVQ  
I;w!  
COATING PROPERTIES +mWf$+w  
  1 0 'REFLECT' 4:/V
|E\D  
  0 0 'ABSORB' jC'h54,Mr  
un 5r9  
PARABASAL 4 hP)Zm%@0f  
BEAMS COHERENT DIFFRACT _bCAZa&&  
WIDTHS 1.6 t1w]L  
o-@01_j  
A=1   \#,2#BmO"E  
N=32   ?z.?(xZ 6  
L=(N)*(A)   #KiJ{w'  
D1=0.625E-3     Z{B  e  
D2=(N)*(D1) K;6#v%  
!! 微阶梯镜======================= Q'n+K5&p  
$DO -16 15 1 ],weqs  
{SURFACE zpwoK&T+  
   PLANE Z 0 RECTANGLE (A)/2 (L)/2 A;L ]=J  
OBJECT 'MIRROR2_?' A&M_ 
J  
   INTERFACE COATING REFLECT AIR AIR    2 q4p-  
   SHIFT X (A)*?+(A)/2 t)&U'^  
   SHIFT Z (D2)*?   a>OYJe  
}   Br!;Ac&N  
GROUP MIRROR2_? <mFDC?j  
  SHIFT Z (L) YD[HBF)~j  
  ROTATE X -90 0 0   +E</A:|}S  
!! DETECTOR======================   *V kaFQZ$,  
SURFACE vi}16V84l  
  PLANE Y -(2*L) RECTANGLE (L)/2 (L)/2 GY%5N= u  
OBJECT 'DETECTOR' )9nW`d+  
  INTERFACE COATING ABSORB AIR AIR   dNgA C){w  
!! SOURCE ======================= s>/Xb2\  
GRID RECT Y -(L) -(L)/2 (L)/2 -(L)/2 (L)/2 (256) (256) b1?^9c#0d  
  SOURCE DIR 0 1 0 Sh(ys*y>  
!! !!TRACE PLOT========================= + Tp% *  
!!WINDOW Y Z oE+P=  
!!PLOT FACETS 5 5 !!OVERLAY qGA|.I9,  
TRACE!! PLOT ;d}>8w&tfy  
!!$VIEW   FygNWI'  
}*(_JR4G  
CONSIDER ONLY DETECTOR !!CONSIDER ONLY DUMY 3Rb#!tx9  
WINDOW X -(L)/2 (L)/2 Z -(L)/2 (L)/2   3`&FXgo  
PIXELS (256) 3WP\
MM  
SPREAD NORMAL $sY'=S  
DISPLAY !K(  
!!  FORM 0.5 ~-k,$J?7  
  PICTURE %e]G]B%  
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.