[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： e"{"g[b/7  
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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。 k\dPF@~Hvl  
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背景： rKT.~ZP\  
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。 wf\7sz  
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。 7xux%:BN  
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步骤 &N+`O)$  
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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。 nII#uI/!q  
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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） BSJS4+,E  
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 -AolW+Y  
例如下所示： C+%eT&
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Sample name:  EDF-C1-56 kg7bZ  
Merging data from file EDF-C1-56 0-0.txt WSv%Rxr8L  
Finished merging RPC data for sample EDF-C1-56 X?&{< vz  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt kUT^o  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 C@zG(?X  
a. 创建一个新的散射库 PBFpV8P,  
b. 散射模型命名 SXO.|"M  
c. 改变散射模型为“Tabulated BSDF”. ;_|4c7
  
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 ） #Ak|p#7 ^  
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。 ZH>i2|W<  
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， |-S+x]9  
g. 点击OK :*DWL!a  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 lFSvHs5  

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脚本代码： E`hR(UL ?  
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'#Language "WWB-COM" jAv3qMQA  
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Option Explicit w:iMrQeJg  
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Sub Main v;Q*0%~  
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    'Cleanup 9}Z;(,6/.\  
    ClearOutputWindow() fE&s 6w&  

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    Print "Merging RPC Photonics BSDF Data Files" 6K<o0=,jm2  
    SetTextColor(255,0,0) W=LJhCpRHj  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." z 0zB&}  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." ) j&khHD  
    SetTextColor(0,0,0) *QIYq  
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    'Current directory of this script (should be the same as the text files being merged) >j$a
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    Dim cDir As String /me ]sOkn  
    cDir = MacroDir$ & "\" %g89eaEZ  
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    'Array which will be populated with the list of files to be merged &,:!
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    Dim fList() As String, curFile As String iQT0%WaHl  
    GetFileList( cDir, fList ) J7%rP
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    Print "" 5K682+^5  
    Print "Files found for merging:" 'irwecd8  
    For Each curFile In fList #w\x-i|  
        Print Chr(9) & curFile MLM/!N 7  
    Next :A:7^jrhi  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. =h +SZXe<r  
    Dim nameArray() As String, sampName As String m|x_++3  
    nameArray = Split(fList(0)," 0-0.txt") 0R`>F">  
    sampName  = nameArray(0) ^,vFxN--q  
    Print "" A #m_w*  
    Print "Sample name: " & Chr(9) & sampName  "^BA5  
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    'Open an output file and write the FRED header data rz-61A) _  
    Dim outFile As String {D|ST2:E  
    outFile = cDir & sampName & "_FRED.txt" x _d   
    Open outFile For Output As #1 ,{msJyacmR  
    Print #1, "type bsdf_data" 8'bZR]  
    Print #1, "format angles=deg bsdf=value scale=1" z8%qCq  
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    'Loop the file list, skip the two header lines and write the remaining data to file Eyk:pnKJb  
    Dim lineArray() As String, curLine As Long BD}%RTeWKq  
    For Each curFile In fList ?u".*!%  
        Print "Merging data from file " & curFile >SziRm>Y7  
        ReadFile( cDir & curFile, lineArray ) ZGI<L  
        For curLine = 2 To UBound(lineArray) 2J$vX(  
            Print #1, lineArray(curLine) ]q[(z  
        Next Nge@8  
    Next aaN
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    'Close the output file D)l\zs%ie  
    Close #1 |22vNt_  
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    Print "Finished merging RPC data for sample " & sampName Vkd_&z7  
    Print "FRED formatted data file: " & Chr(9) & outFile h05FR[</  
End Sub 1q5S"=+W[  
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'Utility function to read the contents of a file into an array of strings. UWS 91GN@  
Function ReadFile(ByVal fileName As String, _ n_ ?+QF  
                  ByRef lineArray() As String) As Long s6(md<r  
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    ReadFile = -1 +F-Y^):  
    Dim oFSO As Object ,,80nW9E  
    Set oFSO = CreateObject("Scripting.FileSystemObject") ~&F|g2:  
    Erase lineArray x5pu+-h  
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    Dim fid As Long 5M #',(X  
    If oFSO.fileexists( fileName ) Then jOGiT|A  
        fid = FreeFile() O0`ofFN  
        Open fileName For Input As fid 0`p"7!r  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) )D'#>!Y  
        Close fid TvT>UBqj=  
    End If Ex*{iJ;\  
    Set oFSO = Nothing ,3MHZPJ?k]  
    Return UBound( lineArray ) }aXSMxCd  
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End Function jTV4iX  
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Sub GetFileList( ByVal in_dir As String, _ pr4y*!|Y$  
                 ByRef in_flist() As String ) a|4D6yUw|  
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    'Redimension the file list array T \- x3i  
    Erase in_flist Lyn{Uag  
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    'Tracks how many files are found \pT
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    Dim fCount As Long WJa7  
    fCount = 0 B~qo^ppVU  
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    'Recurse directory and search for text files sMUpkU-  
    Dim f As String L ed{#+  
    f = Dir$(in_dir & "*.txt") /?XI,#j3kM  
    While f <> "" 52Dgul  
        ReDim Preserve in_flist(fCount) [P ;fv  
        in_flist(fCount) = f }0@@_Y]CC  
        fCount += 1 u(f;4`  
        f = Dir$() /dvronG  
    Wend i`];xNR'  
    ReDim Preserve in_flist(fCount-1) 7,Z<PE  
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End Sub yIngenr$