[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： Wl^/=I4p#  
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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。 b]s%B.h  
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背景： _@}MGWlAPt  
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。 R _~m\P  
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。 `XRb:d^  
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步骤 +BTNm66Z  
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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。 m0q`A5!)  
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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） XzTH,7[n  
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 0Ci"tA3"  
例如下所示： GqF.T#|  
Sample name:  EDF-C1-56 lQ(BEv"2G[  
Merging data from file EDF-C1-56 0-0.txt smQpIB;  
Finished merging RPC data for sample EDF-C1-56 Ny&Fjzl  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt .$T:n[@  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 "$wPq@  
a. 创建一个新的散射库 [n@!=T  
b. 散射模型命名 =Z$=-\<x0.  
c. 改变散射模型为“Tabulated BSDF”. (Os OPTp  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） I@3c QxI  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 6d?2{_},  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， 3qwYicq,  
g. 点击OK K^1O =1gY  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 oew]ijnB  
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脚本代码： eDMwY$J  
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'#Language "WWB-COM" .TrQ +k>  
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Option Explicit h[v3G<C~r  
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Sub Main 7)5$1  
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    'Cleanup F/,<dNJ  
    ClearOutputWindow() XIW:Nk!S  
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    Print "Merging RPC Photonics BSDF Data Files" CjukD%>sde  
    SetTextColor(255,0,0) /xbF1@XtL  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." 4Xho0lO&  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." E3C[o! 5  
    SetTextColor(0,0,0) ~m=%a  
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    'Current directory of this script (should be the same as the text files being merged) ^+l\YB7pD  
    Dim cDir As String Pj5#G0i%  
    cDir = MacroDir$ & "\" -{sv3|P>  
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    'Array which will be populated with the list of files to be merged (dprY1noC  
    Dim fList() As String, curFile As String = 8e8!8  
    GetFileList( cDir, fList ) :^L]Da3  
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    Print "" >Ezwl5b  
    Print "Files found for merging:" %Yn)t3d  
    For Each curFile In fList $%"}N_M  
        Print Chr(9) & curFile Y>m=cqR  
    Next JBJ7k19;  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. P T.jR*  
    Dim nameArray() As String, sampName As String HP
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    nameArray = Split(fList(0)," 0-0.txt") hd BC ^n  
    sampName  = nameArray(0) ~"YNG?Rre  
    Print "" *^5,7}9Qo  
    Print "Sample name: " & Chr(9) & sampName ,5"]K'Vce  
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    'Open an output file and write the FRED header data n\p\*wb  
    Dim outFile As String QYb?;Z  
    outFile = cDir & sampName & "_FRED.txt" #C7j|9Ew1]  
    Open outFile For Output As #1 0e](N`  
    Print #1, "type bsdf_data" [$Bb'],k  
    Print #1, "format angles=deg bsdf=value scale=1" aM}"DY-_ h  
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    'Loop the file list, skip the two header lines and write the remaining data to file +E[
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    Dim lineArray() As String, curLine As Long D8{HOv;d^  
    For Each curFile In fList pREYAZh  
        Print "Merging data from file " & curFile {EN@,3bA  
        ReadFile( cDir & curFile, lineArray ) *g6o ;c  
        For curLine = 2 To UBound(lineArray) zQ+t@;g1  
            Print #1, lineArray(curLine) JB_`lefW,'  
        Next E\N=p&g$  
    Next wdV?&W+  
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    'Close the output file 0l@+xS;  
    Close #1 tP{$}cEY  
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    Print "Finished merging RPC data for sample " & sampName )fL*Ws6  
    Print "FRED formatted data file: " & Chr(9) & outFile `\0a5UFR  
End Sub "uC*B4`  
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'Utility function to read the contents of a file into an array of strings. 04d$_1:}a  
Function ReadFile(ByVal fileName As String, _ w8ld*z  
                  ByRef lineArray() As String) As Long *v3 |  
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    ReadFile = -1 ljON_*  
    Dim oFSO As Object V
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    Set oFSO = CreateObject("Scripting.FileSystemObject") <~+  
    Erase lineArray NyLnE  
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    Dim fid As Long rv%[?Ml  
    If oFSO.fileexists( fileName ) Then d~8~RT2m  
        fid = FreeFile() RBD MZ  
        Open fileName For Input As fid 1iDo$]TEK  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) H12@12v  
        Close fid  O+j:L  
    End If J,Ap9HJt  
    Set oFSO = Nothing GA}^Rh`T-  
    Return UBound( lineArray ) _AbEQ\P{  
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End Function +cH(nZ*f  
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Sub GetFileList( ByVal in_dir As String, _ j@!}r|-T  
                 ByRef in_flist() As String ) <z)G& h@  
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    'Redimension the file list array e8bJ]  
    Erase in_flist 3>Snd9Q  
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    'Tracks how many files are found I!D*(>  
    Dim fCount As Long n#cN[C9  
    fCount = 0 [+z:^a1?V  
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    'Recurse directory and search for text files Y cpO;md  
    Dim f As String q04Dj-2<  
    f = Dir$(in_dir & "*.txt") -+_&#twU  
    While f <> "" 3PffQ,c[~  
        ReDim Preserve in_flist(fCount) 5 ZPUY  
        in_flist(fCount) = f |lV9?#!  
        fCount += 1 -+|[0hpw  
        f = Dir$() G- WJlu  
    Wend V0i$"|F+E  
    ReDim Preserve in_flist(fCount-1) AAgA]OD,  
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End Sub Sw'?$j^3