[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？ j+v=Ul|l  
以下是我的ＡＳＡＰ代码，可以拷贝运行一下。 PQ$%H>{  
Jidwt$1l(  
SYSTEM NEW ` 3K)GA  
RESET o.\F.C$  
uw+M  
UNITS MM bTs?!~q  
WAVELENGTHS 3.7 UM >y:,9;  
\<TXS
)w]  
COATING PROPERTIES >{J(>B
\  
  1 0 'REFLECT' :I^;jdL  
  0 0 'ABSORB' !lc[  
<.izVD4/Gg  
PARABASAL 4 XtSkh] #z!  
BEAMS COHERENT DIFFRACT +8Ymw:D7a  
WIDTHS 1.6 2/=l|!JKLz  
O]Qd<%V'x  
A=1   (tw)nF  
N=32   6?~"V  
L=(N)*(A)   oij}'|/Jc  
D1=0.625E-3     3r."j2$Hs0  
D2=(N)*(D1) TXvI4"&  
!! 微阶梯镜======================= 9=h'9Wo  
$DO -16 15 1 v+#}rUTF  
{SURFACE [o+q>|q  
   PLANE Z 0 RECTANGLE (A)/2 (L)/2 T\j{Bi5 \J  
OBJECT 'MIRROR2_?' \k!{uRy'  
   INTERFACE COATING REFLECT AIR AIR   8~z~_TD6m@  
   SHIFT X (A)*?+(A)/2 D}8[bWF  
   SHIFT Z (D2)*?   /Uy"M:|V1  
}   QD*35Y!d  
GROUP MIRROR2_? (~wqa 3  
  SHIFT Z (L) OO*zhGD;[  
  ROTATE X -90 0 0   Jx7C'~,J  
!! DETECTOR======================   64G[|" j D  
SURFACE ={d>iByq  
  PLANE Y -(2*L) RECTANGLE (L)/2 (L)/2 (I{rLS!o,L  
OBJECT 'DETECTOR' 2:7zG"$  
  INTERFACE COATING ABSORB AIR AIR   /-+xQn]  
!! SOURCE ======================= ]<rkxgMW>  
GRID RECT Y -(L) -(L)/2 (L)/2 -(L)/2 (L)/2 (256) (256) Mh/dpb\Z  
  SOURCE DIR 0 1 0 >A"v ed8  
!! !!TRACE PLOT========================= bITP
Q7+  
!!WINDOW Y Z @ljA  
!!PLOT FACETS 5 5 !!OVERLAY ~8P!XAU56%  
TRACE!! PLOT qr4pR-Gdr  
!!$VIEW   7gvnl~C(  
L`p4->C9A  
CONSIDER ONLY DETECTOR !!CONSIDER ONLY DUMY Be=u&T:~  
WINDOW X -(L)/2 (L)/2 Z -(L)/2 (L)/2   RcM/!,B  
PIXELS (256) :xv!N*Le  
SPREAD NORMAL kJzoFFWo$  
DISPLAY T;y>>_,  
!!  FORM 0.5 -$jEfi4I  
  PICTURE ``Dq  
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.