[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： a<%Ivqni  
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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。 fmqHWu*wG  
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背景： #.1+-^TQk  
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。 X2CpA;#;7l  
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。 zx:Qz  
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步骤 tzH~[n,  
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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。 44e
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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） Uwj|To&QR  
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
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例如下所示： &lnr?y^  
Sample name:  EDF-C1-56 mdzUL d5J  
Merging data from file EDF-C1-56 0-0.txt |HT5G=dw
 
Finished merging RPC data for sample EDF-C1-56 .W;,~.l  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt )96tBA%u  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 lVb{bO9-O  
a. 创建一个新的散射库 2
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b. 散射模型命名 {=3&_/9s){  
c. 改变散射模型为“Tabulated BSDF”.
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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 ） {,:yZ&(  
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。 z89
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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， H3Ws$vl9n  
g. 点击OK w|t}.u  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 =Oyn<  
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脚本代码： mz-sazgV  
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'#Language "WWB-COM" 9E`Laf  
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Option Explicit ya`Z eQ-p  
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Sub Main BIQQJLu  
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    'Cleanup l%\p  
    ClearOutputWindow() o5h*sQ9  
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    Print "Merging RPC Photonics BSDF Data Files" lf`" (:./  
    SetTextColor(255,0,0) dbe\ YE  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." S
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    Print "Note: Do not run this script multiple times without deleting the output file between executions." |BA&ixHe~C  
    SetTextColor(0,0,0) @~ 6,8nQ  
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    'Current directory of this script (should be the same as the text files being merged) \&XtPQ  
    Dim cDir As String (&o|}"kRq  
    cDir = MacroDir$ & "\" m#Y[EPF=|  
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    'Array which will be populated with the list of files to be merged b)(si/]\  
    Dim fList() As String, curFile As String \281X  
    GetFileList( cDir, fList ) /mK."5-cm  
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    Print "" "=Xky,k  
    Print "Files found for merging:"
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    For Each curFile In fList TdKo"H*C  
        Print Chr(9) & curFile prw% )#,  
    Next |s!<vvp]  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. q.:j yj6  
    Dim nameArray() As String, sampName As String nvInq2T
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    nameArray = Split(fList(0)," 0-0.txt") x'iBEm  
    sampName  = nameArray(0) cgV5{|P  
    Print "" U-.A+#<IT9  
    Print "Sample name: " & Chr(9) & sampName Q$^)z_jai  
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    'Open an output file and write the FRED header data `p#u9M>  
    Dim outFile As String Yc`PK =!l  
    outFile = cDir & sampName & "_FRED.txt"
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    Open outFile For Output As #1 tq.g4X ;_  
    Print #1, "type bsdf_data" 6[T)Q^0`  
    Print #1, "format angles=deg bsdf=value scale=1" 9i`MUE1Sh  
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    'Loop the file list, skip the two header lines and write the remaining data to file -~NjZ=vPh  
    Dim lineArray() As String, curLine As Long @W.0YU0|J  
    For Each curFile In fList 3kJ7aBiR<  
        Print "Merging data from file " & curFile &Db'}Y?x]  
        ReadFile( cDir & curFile, lineArray ) \R.Fmeko  
        For curLine = 2 To UBound(lineArray) =`+c}i?  
            Print #1, lineArray(curLine) ^!7|B3`  
        Next OI)U c .  
    Next :F.eyA|#@G  
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    'Close the output file V8947h|&  
    Close #1 _edT+r>+  
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    Print "Finished merging RPC data for sample " & sampName y{9<>28  
    Print "FRED formatted data file: " & Chr(9) & outFile +![\7  
End Sub [&5%$ T  
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'Utility function to read the contents of a file into an array of strings. xX~; /e&,  
Function ReadFile(ByVal fileName As String, _ UNCI"Mjb  
                  ByRef lineArray() As String) As Long f-5}`)`.+  
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    ReadFile = -1 t-Zk)*d/0  
    Dim oFSO As Object ia*Bcx_RW+  
    Set oFSO = CreateObject("Scripting.FileSystemObject") K*aGz8N  
    Erase lineArray nC@UK{tVa  
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    Dim fid As Long `{+aJ0<S  
    If oFSO.fileexists( fileName ) Then fctVJ{?  
        fid = FreeFile() pIgjo>K  
        Open fileName For Input As fid PS/00F/Ak  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) PbIir=  
        Close fid ]}9D*V  
    End If 9t"/@CH{  
    Set oFSO = Nothing %&&;06GU}  
    Return UBound( lineArray ) 9V?:!%J  
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End Function $@eFSA5k,7  
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Sub GetFileList( ByVal in_dir As String, _ Nrfj[I  
                 ByRef in_flist() As String ) FQO>%=&4  
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    'Redimension the file list array 9D H
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    Erase in_flist Ji;R{tZ.R  
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    'Tracks how many files are found c n^z=?  
    Dim fCount As Long dL|*#e  
    fCount = 0 }
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    'Recurse directory and search for text files 9Fh1rZD<  
    Dim f As String T]y^PT<8?  
    f = Dir$(in_dir & "*.txt") l>?k>NEpP  
    While f <> "" g6(u6%MD  
        ReDim Preserve in_flist(fCount) !~a1xI~s  
        in_flist(fCount) = f wKj0vMW  
        fCount += 1 f4lC*nCN  
        f = Dir$() b:YyzOqEu  
    Wend ]V.0%Ccw;.  
    ReDim Preserve in_flist(fCount-1) >@i{8AD  
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End Sub J/ZC<dkYQ