[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： IQBL;=.J.  
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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。 dwn|1%D  
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背景： P0UR{tK  
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。 l<_v3/3  
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。 +9HU&gQ3  
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步骤 QmBHD;Gf  
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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。 eGMw:H  
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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） 5]
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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 &Zz&VwWR  
例如下所示： |(~IfSE2  
Sample name:  EDF-C1-56 7:~3B-Tb  
Merging data from file EDF-C1-56 0-0.txt ,5 ,r.  
Finished merging RPC data for sample EDF-C1-56 A7QT4h&6  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt ['(qeS@5O  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 d Np%=gIj  
a. 创建一个新的散射库 K81FKV.  
b. 散射模型命名 D*L@I@ [  
c. 改变散射模型为“Tabulated BSDF”. uJ"#j X  
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 ） X>dQK4!R  
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。 8Ogg(uS70'  
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， PR;Bxy  
g. 点击OK +46& Zb35  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 DI{Qs[  
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脚本代码： !le#7Kii  
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'#Language "WWB-COM" FkMM>X  
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Option Explicit dsEvpa$
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Sub Main ILG&l<!E  
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    'Cleanup C B;j[.  
    ClearOutputWindow() lyowH{.N"3  
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    Print "Merging RPC Photonics BSDF Data Files" 6/a%%1c1  
    SetTextColor(255,0,0) c7rC!v  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." TPJuS)TU9  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." Na\&}GSf^  
    SetTextColor(0,0,0) p@$92> '  
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    'Current directory of this script (should be the same as the text files being merged) fN`Prs A  
    Dim cDir As String z#5qI',L  
    cDir = MacroDir$ & "\" *R&77 o7  
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    'Array which will be populated with the list of files to be merged _Wp, z`  
    Dim fList() As String, curFile As String 8yr-X!eF  
    GetFileList( cDir, fList ) n`Ypv{+ {%  
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    Print "" @ /e{-Q  
    Print "Files found for merging:" .j!:Hp(z}  
    For Each curFile In fList _=w=!U
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        Print Chr(9) & curFile 'mU\X!- 4<  
    Next H8c -/  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. V" 5rIk  
    Dim nameArray() As String, sampName As String h#h)=;  
    nameArray = Split(fList(0)," 0-0.txt") 8LtkP&Wx  
    sampName  = nameArray(0) Ze`ms96j{  
    Print "" ohPXwp?]  
    Print "Sample name: " & Chr(9) & sampName Y Odwd}M  

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    'Open an output file and write the FRED header data o>M&C X+j$  
    Dim outFile As String J@Nq  
    outFile = cDir & sampName & "_FRED.txt" yX\~{%  
    Open outFile For Output As #1 1 RyvPP  
    Print #1, "type bsdf_data" Kn+
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    Print #1, "format angles=deg bsdf=value scale=1" 3k+46Wp  
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    'Loop the file list, skip the two header lines and write the remaining data to file l%cE o`U  
    Dim lineArray() As String, curLine As Long 
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    For Each curFile In fList ^O5PcV3Eg  
        Print "Merging data from file " & curFile *=QWx[K|  
        ReadFile( cDir & curFile, lineArray ) ~:A=o?V2  
        For curLine = 2 To UBound(lineArray) X{5(i3?S  
            Print #1, lineArray(curLine) a '<B0'  
        Next %tz foiJ%P  
    Next g<4@5OQKu  
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    'Close the output file ~ Q;qRx  
    Close #1 ;#2yF34gv  
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    Print "Finished merging RPC data for sample " & sampName |P=-m-W  
    Print "FRED formatted data file: " & Chr(9) & outFile M[dJQ(  
End Sub E7Pz~6  
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'Utility function to read the contents of a file into an array of strings. [M.!7+$o  
Function ReadFile(ByVal fileName As String, _ "Kn%|\YL@4  
                  ByRef lineArray() As String) As Long 9
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    ReadFile = -1 z!\)sL/"  
    Dim oFSO As Object GA)t!Xg^  
    Set oFSO = CreateObject("Scripting.FileSystemObject") 7gbu7"Qc  
    Erase lineArray 8<g9 ~L  
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    Dim fid As Long bu r0?q
  
    If oFSO.fileexists( fileName ) Then 4}HY= 0Um  
        fid = FreeFile() RS[QZOoW}  
        Open fileName For Input As fid czp}-{4X  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) !.5,RIf  
        Close fid q6>%1~?  
    End If OM7EmMa;  
    Set oFSO = Nothing LZ*ZXFIg  
    Return UBound( lineArray ) ER$qL"H U  
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End Function >*goDtTjp  
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Sub GetFileList( ByVal in_dir As String, _ S_56!  
                 ByRef in_flist() As String ) L(qQ,1VY  
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    'Redimension the file list array Sy`7})[  
    Erase in_flist [E|%  
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    'Tracks how many files are found <MBpV^Y}  
    Dim fCount As Long A^"( VaK  
    fCount = 0 G$$y\e$  
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    'Recurse directory and search for text files vTU*6
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    Dim f As String loFApBD=$^  
    f = Dir$(in_dir & "*.txt") 1|Z!8:&pj  
    While f <> "" ,O/ t6'  
        ReDim Preserve in_flist(fCount) "_T8Km008  
        in_flist(fCount) = f |.Y}2>{  
        fCount += 1 &C=[D_h  
        f = Dir$() [oh0 )wzB  
    Wend i_6 Y
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    ReDim Preserve in_flist(fCount-1) f& >[$zh  
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End Sub g/6>>p`J