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？ $ T2 n^yz
以下是我的ＡＳＡＰ代码，可以拷贝运行一下。 _ /pdZM,V
{8im{]8_
SYSTEM NEW K /A1g.$
RESET &60#y4
O_^X:0}
UNITS MM ,\CG}-v@CN
WAVELENGTHS 3.7 UM p+.{ "%
\f-HfYG
COATING PROPERTIES Qh {]gw-6
1 0 'REFLECT' =JDa[_lpN
0 0 'ABSORB' -I zc-W
W^T6^q5;H
PARABASAL 4 dt1,! sHn
BEAMS COHERENT DIFFRACT @'lO~i
WIDTHS 1.6 wf&1,t3Bgn
,]cb3nP
A=1 *<IQ+oat,a
N=32 ;FH_qF`.
L=(N)*(A) .4cOMi G
D1=0.625E-3 > Du>vlT Y
D2=(N)*(D1) <uL0 M`u3
!! 微阶梯镜======================= KOP*\ \1
J
$DO -16 15 1 >XomjU[srQ
{SURFACE O ]Stf7]%;
PLANE Z 0 RECTANGLE (A)/2 (L)/2 K4|{[YpPB
OBJECT 'MIRROR2_?' ,]. S~6IM
INTERFACE COATING REFLECT AIR AIR +jrMvk"
SHIFT X (A)*?+(A)/2 'X ]m y
SHIFT Z (D2)*? qE)G;Y<,1
} 6u-a V
GROUP MIRROR2_? f^D4aEU
SHIFT Z (L) $/XR/
ROTATE X -90 0 0 ?D]q w4 J
!! DETECTOR====================== $P7G,0-
SURFACE F3,djZq
PLANE Y -(2*L) RECTANGLE (L)/2 (L)/2 TkjPa}; R
OBJECT 'DETECTOR' [R9!Tz
INTERFACE COATING ABSORB AIR AIR ?[~)D}] j
!! SOURCE ======================= vp#r :+=
GRID RECT Y -(L) -(L)/2 (L)/2 -(L)/2 (L)/2 (256) (256) ^{(i;IVG
SOURCE DIR 0 1 0 ypA)G /;
!! !!TRACE PLOT========================= NX5NE2@^qH
!!WINDOW Y Z DU OS L
!!PLOT FACETS 5 5 !!OVERLAY F ?!
TRACE!! PLOT _0c$SK
!!$VIEW o7#Mr`6H
|= U(8t
CONSIDER ONLY DETECTOR !!CONSIDER ONLY DUMY 8~s-@3J
WINDOW X -(L)/2 (L)/2 Z -(L)/2 (L)/2 @[] A&)B
PIXELS (256) j"Vb8}
SPREAD NORMAL .}||!
DISPLAY jpW(w( $XL
!! FORM 0.5 9X[}ik0
PICTURE AG==A&d>$
RETURN
