[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？ ?N+pWdi  
以下是我的ＡＳＡＰ代码，可以拷贝运行一下。 MP@}G$O  
?st}rJ_  
SYSTEM NEW =.J>'9Q  
RESET *XDe:A  
V[^AV"V  
UNITS MM 1h162  
WAVELENGTHS 3.7 UM \Rt>U|%  
7!o
#pt7  
COATING PROPERTIES D}{]5R  
  1 0 'REFLECT' O d6'bO;G  
  0 0 'ABSORB' wko9tdC=U  
!}`[s2ji  
PARABASAL 4 ELG{xN=o  
BEAMS COHERENT DIFFRACT t ~]' {[F  
WIDTHS 1.6 )g&nI<Mh  
b!QRD'31'j  
A=1   N>s3tGh  
N=32   p&xj7qwp@F  
L=(N)*(A)   %"E!E1_Sv  
D1=0.625E-3     qbD_  
D2=(N)*(D1) ,o `tRh
<  
!! 微阶梯镜======================= rCGKE`H
 
$DO -16 15 1 _M>S=3w  
{SURFACE 2 =>3B  
   PLANE Z 0 RECTANGLE (A)/2 (L)/2 KLj/,ehD !  
OBJECT 'MIRROR2_?' RT%{M1tkS  
   INTERFACE COATING REFLECT AIR AIR   /lHs]) ,  
   SHIFT X (A)*?+(A)/2 RXWdqaENx  
   SHIFT Z (D2)*?   zEE:C|50  
}   oY\;KPz  
GROUP MIRROR2_? :E|+[}|  
  SHIFT Z (L) j9%vw.3b  
  ROTATE X -90 0 0   rJp9ut'FEz  
!! DETECTOR======================   ]RVme^=  
SURFACE {j[*:l0Ui  
  PLANE Y -(2*L) RECTANGLE (L)/2 (L)/2 #5{lOeN  
OBJECT 'DETECTOR' za.^vwkBk2  
  INTERFACE COATING ABSORB AIR AIR   =xH>,-8}  
!! SOURCE ======================= Y}\3PaUa  
GRID RECT Y -(L) -(L)/2 (L)/2 -(L)/2 (L)/2 (256) (256) :W'.SRD  
  SOURCE DIR 0 1 0 vMXn#eR  
!! !!TRACE PLOT========================= T
z(Dhb,  
!!WINDOW Y Z ]
VN1Y)  
!!PLOT FACETS 5 5 !!OVERLAY $reQdN=~  
TRACE!! PLOT b3=XWzK5  
!!$VIEW   N9H qFp  
t/]za4w/  
CONSIDER ONLY DETECTOR !!CONSIDER ONLY DUMY Hc0V4NHCaL  
WINDOW X -(L)/2 (L)/2 Z -(L)/2 (L)/2   +b dnTV6  
PIXELS (256) =lh&oPc1  
SPREAD NORMAL }V+&o\4  
DISPLAY xLbF9ASim  
!!  FORM 0.5 4 $)}d  
  PICTURE |z)7XK  
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.