[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： RG:_:%@%}  
4o<' fY  
RPC Photonics公司有高品质的的工程漫射体BSDF测试数据，但它对于FRED帮助甚少，下面这个步骤描述了如何利用FRED脚本转换RPC Photonics提供的TXT文件，并将数据直接应用到FRED的Tabulated scatter 散射模型。 up2wkc8  
!+(H(,gI  
背景： F#a'N c9  
Thorlabs和RPC Photonics联手共同推出的新型漫射体及光束整形技术，可以解决其他技术的不足，大大改善了诸如光刻系统、有效固态照明，显示，背光，显示亮度增强和投影屏等大多数应用的性能。这项我们称之为工程漫射体（Engineered DiffusersTM）的新概念，与其他技术有许多不同。与诸如磨砂玻璃、乳色玻璃和全息元件等随机漫射体截然不同，工程漫射体要求对于每个散射中心，通常为微透镜单元，都进行控制。例如全息漫射体可以视为一组随机排列的透镜，但是通过全息曝光形成的类透镜效果只能通过静态方式进行控制：而无法单独操控每个微透镜单元，这也帮助解释了全息漫射体无法控制光的分布和轮廓。另一方面，在工程漫射体中，每个微透镜单元形成漫射体，由其凹形纵断面和在阵列中的位置所确定。同时，为了确保漫射体不受输入光束变化的影响，并且不产生衍射效果，微透镜单元的分布是随机的，根据产生相应的光束形状函数所选取的概率分布函数来确定。因此，工程漫射体同时保留了随机与确定性漫射体的优点，从而实现高性能的光束整形功能。 +S@[1 N  
FRED是美国Photon Engineering 公司开发的光学工程仿真软件，其在杂散光分析中独特的算法、高效的准确性，使其与其它同类产品相比更具优势。本案例我们重点讲述如何由RPC Photonics的BSDF数据转为FRED可识别的散射数据。 cH6J:0>W  
eC`G0.op  
H3+P;2{  
w d6+,B  
步骤 oB+Ek~{z]  

|%@pjJ`3  
1、 在http://www.rpcphotonics.com/bsdf-data-optical-diffusers/下载并解压BSDF数据到某一文件夹下，选择“Raw data”文件。 DDe`Lb%%  
0~BZh%s< (  
XA\wZV |{  
2、 将     http://fred-kb.photonengr.com/wp-content/uploads/sites/2/2015/06/constructRpcScatterFile.frs脚本文件放在步骤1中的文件下。（脚本代码放在了本文的最后） Bh;N:{&^Eu  
3、 打开FRED并运行脚本文件，会输出如下“<SAMPLE>_FRED.txt”格式，<SAMPLE>即为RPC Photonics散射片数据集 @PV3G KJ  
例如下所示： {J-Ojw|Y b  
Sample name:  EDF-C1-56 i93^E~q]  
Merging data from file EDF-C1-56 0-0.txt EZ[e a<  
Finished merging RPC data for sample EDF-C1-56 KebC$g@W  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt f1q0*
)fk  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 _|7bpt
9  
a. 创建一个新的散射库 o\X|\nUk  
b. 散射模型命名 d 9]zB-A  
c. 改变散射模型为“Tabulated BSDF”. >aT~G!y  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ）
hbm#H7Y  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 nnCz!:9p  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， ?~<NyJHN%  
g. 点击OK u<EPK*O*  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 6S^JmYq  
=m6<H  
Wa9yyc  
脚本代码： i4mP*RwC  
/|@~:5R5H  
'#Language "WWB-COM" ]xPy-j6C  
i<*W,D6  
Option Explicit c
G{  
6foiN W+  
Sub Main r-,u)zf"  
\pXo~;E
\  
    'Cleanup 0F6~S   
    ClearOutputWindow() @4$la'XSx  
.:=5|0m  
    Print "Merging RPC Photonics BSDF Data Files" )B"E+Q'h{7  
    SetTextColor(255,0,0) XRi37|p  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." A}i>ys  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." _7 ^:1i~:.  
    SetTextColor(0,0,0) fDAT#nlyp  
g#o9[su  
    'Current directory of this script (should be the same as the text files being merged) ,
;n[_f  
    Dim cDir As String Jt3*(+J>/  
    cDir = MacroDir$ & "\" :VE0eJ]J6  
mt4X  
    'Array which will be populated with the list of files to be merged Z61L;E  
    Dim fList() As String, curFile As String f<>CSjQ4c  
    GetFileList( cDir, fList ) sU/vXweky"  
R#!U
rhh  
    Print "" WQMoAPfqL  
    Print "Files found for merging:" T-Yb|@4  
    For Each curFile In fList bd[iD?epD]  
        Print Chr(9) & curFile b{;LbHq+G  
    Next 2yVQqwQm  
PoD/i@  
    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. ;f /2u  
    Dim nameArray() As String, sampName As String Zi<(>@z2  
    nameArray = Split(fList(0)," 0-0.txt") on 4 $n7  
    sampName  = nameArray(0) )NO,G  
    Print "" dv?t;D@p!  
    Print "Sample name: " & Chr(9) & sampName XI"IEwB  
zpg5
12\y  
    'Open an output file and write the FRED header data M,we,!B0  
    Dim outFile As String rVwW%&  
    outFile = cDir & sampName & "_FRED.txt" A@e!~  
    Open outFile For Output As #1 j|@8Vx
Z  
    Print #1, "type bsdf_data" #I#_gjJkx  
    Print #1, "format angles=deg bsdf=value scale=1" @_?Uowc8  
@{ L|&Mk!  
    'Loop the file list, skip the two header lines and write the remaining data to file 
YTg8Zg-Z  
    Dim lineArray() As String, curLine As Long dRUmC H  
    For Each curFile In fList k0
D):  
        Print "Merging data from file " & curFile v!AfIcEV  
        ReadFile( cDir & curFile, lineArray ) [d=BN ,?  
        For curLine = 2 To UBound(lineArray) #4V->I  
            Print #1, lineArray(curLine) ~J >Jd
 
        Next 3?TUt{3g  
    Next sn+ kFvk}S  
f6
m h_l  
    'Close the output file B/B`=%~5_^  
    Close #1 -c#vWuLl  
_~;K]  
    Print "Finished merging RPC data for sample " & sampName F(w<YU%6  
    Print "FRED formatted data file: " & Chr(9) & outFile cL4Xh|NBp  
End Sub yF-
`f _  
QV -ZP'e^  
'Utility function to read the contents of a file into an array of strings. $5@[l5cJU;  
Function ReadFile(ByVal fileName As String, _ 0> QqsQ  
                  ByRef lineArray() As String) As Long dJ~Occ1~r  
x
u>grj  
    ReadFile = -1 lU`t~|>r+  
    Dim oFSO As Object uEkGo5  
    Set oFSO = CreateObject("Scripting.FileSystemObject") I p|[  
    Erase lineArray ek d[|g  
/< Dtu UM  
    Dim fid As Long QiaB
ZAol  
    If oFSO.fileexists( fileName ) Then gFXz:!A  
        fid = FreeFile() )Jh:~9L%='  
        Open fileName For Input As fid >^g\s]c[  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) $<L@B|}F)  
        Close fid %
0vWyU:K9  
    End If ycf)*0k  
    Set oFSO = Nothing [S0wwWU |0  
    Return UBound( lineArray ) +kq+x6&  
$)6x3&]P  
End Function 8J~-|<Q6  
6Q_ZP#oAV  
Sub GetFileList( ByVal in_dir As String, _ vZPBjloT!.  
                 ByRef in_flist() As String ) I(j$^DA.  
"O_)~u  
    'Redimension the file list array f,Am;:\|  
    Erase in_flist !1l~'/r  
v3wq-  
    'Tracks how many files are found O"wo&5b_  
    Dim fCount As Long m14'u GC  
    fCount = 0 CW FE{  
%0'7J@W  
    'Recurse directory and search for text files Rpj{!Ia  
    Dim f As String Sx1OY0)s  
    f = Dir$(in_dir & "*.txt") z~ua#(z1S  
    While f <> "" GQ sE5Vb  
        ReDim Preserve in_flist(fCount)  p+-IvU  
        in_flist(fCount) = f /)sP<WPQ6  
        fCount += 1 KfQ?b_H.  
        f = Dir$() D#[<N  
    Wend B/Ltb^a  
    ReDim Preserve in_flist(fCount-1) YR[I,j  
cGlpJ)'-{  
End Sub NTVaz.