[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？ Qh|-a@  
以下是我的ＡＳＡＰ代码，可以拷贝运行一下。 ]{AOh2Z.hv  
XWUvP  
SYSTEM NEW v?Yd
LR  
RESET +q #Xy0u  
}_a+X  
UNITS MM hy$M
V3LP  
WAVELENGTHS 3.7 UM c#{Ywh  
{+C%D'  
COATING PROPERTIES vbRrk($`  
  1 0 'REFLECT' Sv~YFS :oy  
  0 0 'ABSORB' (o x4K{  
b`h%W"|2L  
PARABASAL 4 z"6ZDC6
 
BEAMS COHERENT DIFFRACT {t844La"  
WIDTHS 1.6 e8d5(e  
Ad]<e?oN=  
A=1   \3H<z@;  
N=32   y wW-p.  
L=(N)*(A)   3x"@**(Q  
D1=0.625E-3     di3 B=A>3  
D2=(N)*(D1) r@*=|0(OrK  
!! 微阶梯镜======================= ).0V%}>  
$DO -16 15 1 a%7"_{s1  
{SURFACE )(h&Q? Ar  
   PLANE Z 0 RECTANGLE (A)/2 (L)/2 z:Xj_ `p  
OBJECT 'MIRROR2_?' r#_7]_
3  
   INTERFACE COATING REFLECT AIR AIR   pu/m8  
   SHIFT X (A)*?+(A)/2 `e'G.@  
   SHIFT Z (D2)*?   .sd B3x
 
}   qDby!^ryc  
GROUP MIRROR2_? I@3Q=14k%  
  SHIFT Z (L) -"~
L2f"?  
  ROTATE X -90 0 0   )"
(V*Z  
!! DETECTOR======================   *.kj]BoO  
SURFACE P$p@5hl  
  PLANE Y -(2*L) RECTANGLE (L)/2 (L)/2 sg3h i"Im  
OBJECT 'DETECTOR' KI Ek/]<H  
  INTERFACE COATING ABSORB AIR AIR   o"'iXUJ  
!! SOURCE ======================= PHQ{-b?4t  
GRID RECT Y -(L) -(L)/2 (L)/2 -(L)/2 (L)/2 (256) (256) :D"@6PC]  
  SOURCE DIR 0 1 0 y
#b;uDY  
!! !!TRACE PLOT========================= <A#5v\{.;~  
!!WINDOW Y Z IXGW2z;  
!!PLOT FACETS 5 5 !!OVERLAY LQh^; ]^(  
TRACE!! PLOT  M*d-z  
!!$VIEW   !2GHJHxv]c  
KK:N [x  
CONSIDER ONLY DETECTOR !!CONSIDER ONLY DUMY Q,zC_  
WINDOW X -(L)/2 (L)/2 Z -(L)/2 (L)/2   ' 2>l  
PIXELS (256) -1Djo:y  
SPREAD NORMAL |'ZN!2u  
DISPLAY >j&1?M2C  
!!  FORM 0.5 'n~fR]
h}  
  PICTURE LWD.  
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.