[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： 5>CeFy  
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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。 {Fyw<0 [@  
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背景： rGt]YG#C  
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。 A>F&b1  
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。 PIFZ '6gn  
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步骤 Sjwwc6_c  
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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。 C'l\4ij)7  
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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） ;YQ6X>
 
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 wV$V X  
例如下所示： 23p.g5hJi  
Sample name:  EDF-C1-56 b+ZaZ\-y |  
Merging data from file EDF-C1-56 0-0.txt XM?c*,=fu  
Finished merging RPC data for sample EDF-C1-56 }l]r-  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt B}p.fE  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 r[kHVT8  
a. 创建一个新的散射库 Sqmjf@o$>  
b. 散射模型命名 +U<Ae^V
 
c. 改变散射模型为“Tabulated BSDF”. DX3jE p2  
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 ） MfL
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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。 R~TG5^(  
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， l`0JL7  
g. 点击OK >2mY%  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 (lit^v,9  
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脚本代码：
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'#Language "WWB-COM" Wk-.dJ  
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Option Explicit \vj xCkg{  
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Sub Main g8"{smP/  
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    'Cleanup f'S0"  
    ClearOutputWindow() E*9W'e~=  
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    Print "Merging RPC Photonics BSDF Data Files" 4=* ml}RP  
    SetTextColor(255,0,0) Hpp;dG  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." %-!:$ 1;  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." 'xM\txZ;  
    SetTextColor(0,0,0) uA%F0oM  
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    'Current directory of this script (should be the same as the text files being merged) !:g\
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    Dim cDir As String z5[Qh<M  
    cDir = MacroDir$ & "\" '+S!>Lqb  
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    'Array which will be populated with the list of files to be merged #: ,X^"w3  
    Dim fList() As String, curFile As String ,(#n8|q4  
    GetFileList( cDir, fList ) (jE[W:  
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    Print "" L=<,+m[!  
    Print "Files found for merging:" k1FG$1.  
    For Each curFile In fList  bqR0./V  
        Print Chr(9) & curFile m%OX< T!  
    Next N_.`5I;e  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. ;wr]_@<~  
    Dim nameArray() As String, sampName As String +G!;:o  
    nameArray = Split(fList(0)," 0-0.txt") ."v&?o Ck]  
    sampName  = nameArray(0) nQ'AB~ Do  
    Print "" v{U1B
 
    Print "Sample name: " & Chr(9) & sampName K9'AYFse  
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    'Open an output file and write the FRED header data j7Lw(AJ  
    Dim outFile As String @j4~`~8  
    outFile = cDir & sampName & "_FRED.txt" _~ 7cn  
    Open outFile For Output As #1 pM@0>DVi  
    Print #1, "type bsdf_data" W}oAgUd  
    Print #1, "format angles=deg bsdf=value scale=1" rMUQh~a/  
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    'Loop the file list, skip the two header lines and write the remaining data to file ?DJ,YY9P  
    Dim lineArray() As String, curLine As Long :cTwp K  
    For Each curFile In fList 1FC1*7A[  
        Print "Merging data from file " & curFile 
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        ReadFile( cDir & curFile, lineArray ) 9DmQ  
        For curLine = 2 To UBound(lineArray) (KG>lTdN  
            Print #1, lineArray(curLine) DfP vi1  
        Next tZY(r {  
    Next PR1%  
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    'Close the output file Ibl==Irk  
    Close #1 uI[lrMQYa  
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    Print "Finished merging RPC data for sample " & sampName {R.@EFkZ  
    Print "FRED formatted data file: " & Chr(9) & outFile jvos)$;L-  
End Sub [kq+a]q  
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'Utility function to read the contents of a file into an array of strings. Wj.
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Function ReadFile(ByVal fileName As String, _ axi%5:I  
                  ByRef lineArray() As String) As Long &+t,fwlM  
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    ReadFile = -1 /!0{9F<  
    Dim oFSO As Object Ib8xvzR6I&  
    Set oFSO = CreateObject("Scripting.FileSystemObject") niN$!k+Jr  
    Erase lineArray WAcQRa~C  
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    Dim fid As Long pfvNVu  
    If oFSO.fileexists( fileName ) Then ^Q4m1? 40  
        fid = FreeFile() @7';bfsix  
        Open fileName For Input As fid QFf lx  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) Y1vSwS%{T  
        Close fid PDssEb7  
    End If a|@^N  
    Set oFSO = Nothing G%K<YyAP  
    Return UBound( lineArray ) nPUq+cXy]C  
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End Function fXYg %  
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Sub GetFileList( ByVal in_dir As String, _ eESJk14  
                 ByRef in_flist() As String ) P A9 ]L
 
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    'Redimension the file list array n2H2G_-L[  
    Erase in_flist =lG5Kc{B  
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    'Tracks how many files are found ,*V{
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    Dim fCount As Long [0}^w[  
    fCount = 0  B9^@]  
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    'Recurse directory and search for text files ?H3xE=<
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    Dim f As String o^},L?  
    f = Dir$(in_dir & "*.txt") #sEbu^  
    While f <> "" t <#Yr%a  
        ReDim Preserve in_flist(fCount) '5eW"HGU]`  
        in_flist(fCount) = f {j E}mzi  
        fCount += 1 mOyBSOad4  
        f = Dir$() p9 |r y+t  
    Wend Ydu=Jg5u7  
    ReDim Preserve in_flist(fCount-1) ` oYrW0Vm  
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End Sub @&d/}Mx"t