[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： uD{^1c3x  
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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。 EId>%0s5  
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背景： p%Q{Rq
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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。 1z; !)pG.  
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。 J*ofa>  
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步骤 )(d~A?~  
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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。 )4ok@^.  
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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） 8~!h8bkC  
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 lib^JJF  
例如下所示： R0w~ Z   
Sample name:  EDF-C1-56 iyR5mA  
Merging data from file EDF-C1-56 0-0.txt PMiu "  
Finished merging RPC data for sample EDF-C1-56 J>hjIN  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt H>\lE2  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 1)e[F#|  
a. 创建一个新的散射库 \HMuVg'Q  
b. 散射模型命名 M"-53|#:w\  
c. 改变散射模型为“Tabulated BSDF”. t&yuo E  
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 ） %YuFw|wO  
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。 C
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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， ?r$&O*;  
g. 点击OK ?<OE|nb&  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 Nog{w  
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脚本代码： I_c?Ky8J_|  
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'#Language "WWB-COM" .dc|?$XV
 
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Option Explicit pm}_\_  
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Sub Main 3;//o<  
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    'Cleanup 80U(q/H%9  
    ClearOutputWindow() !}
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    Print "Merging RPC Photonics BSDF Data Files" Ch=jt*0  
    SetTextColor(255,0,0) T[ zEAj  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." vA?3kfL|#  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." Sfi1bsK  
    SetTextColor(0,0,0) $-]9/Ct  
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    'Current directory of this script (should be the same as the text files being merged) =4/K#cQ  
    Dim cDir As String ~:b5UIAk  
    cDir = MacroDir$ & "\" M\08 7k  
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    'Array which will be populated with the list of files to be merged ypvz&SzIh  
    Dim fList() As String, curFile As String 4?`*#DPl  
    GetFileList( cDir, fList ) OQ3IkE`G  
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    Print "" {ZUgyGE{  
    Print "Files found for merging:" 2N&S__  
    For Each curFile In fList gp\o|igT  
        Print Chr(9) & curFile C9%A?'`  
    Next PmUq~YZ7  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. vf!lhV-UG+  
    Dim nameArray() As String, sampName As String O2~Q(q'   
    nameArray = Split(fList(0)," 0-0.txt") D'Kiy  
    sampName  = nameArray(0) :<6gP(  
    Print "" ,u5iiR  
    Print "Sample name: " & Chr(9) & sampName 9+'*  
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    'Open an output file and write the FRED header data ?J5E.7o  
    Dim outFile As String `! )^g/>0i  
    outFile = cDir & sampName & "_FRED.txt" +qa^K%K  
    Open outFile For Output As #1 )9{!=k  
    Print #1, "type bsdf_data" \k%j  
    Print #1, "format angles=deg bsdf=value scale=1" )5<c8lzp  
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    'Loop the file list, skip the two header lines and write the remaining data to file Cyp%E5b7  
    Dim lineArray() As String, curLine As Long gGbJk&E  
    For Each curFile In fList [58qC:  
        Print "Merging data from file " & curFile P
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        ReadFile( cDir & curFile, lineArray ) Tu=~iQ  
        For curLine = 2 To UBound(lineArray) iB*1Yy0DC  
            Print #1, lineArray(curLine) p=dM2>  
        Next E>1%7" i<  
    Next <OGXKv@  
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    'Close the output file \~:_h#bW  
    Close #1 ?fvK<0S`  
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    Print "Finished merging RPC data for sample " & sampName MJcWX|(y  
    Print "FRED formatted data file: " & Chr(9) & outFile j>O!|V  
End Sub tf{o=X.)
 
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'Utility function to read the contents of a file into an array of strings. O<+x=>_  
Function ReadFile(ByVal fileName As String, _ |EP=<-|  
                  ByRef lineArray() As String) As Long g-2(W  
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    ReadFile = -1 _vOSOnU  
    Dim oFSO As Object ~ll+/w\4  
    Set oFSO = CreateObject("Scripting.FileSystemObject") RA:3ZV  
    Erase lineArray 3\?y
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    Dim fid As Long y.WEO>  
    If oFSO.fileexists( fileName ) Then ds'7zxy/  
        fid = FreeFile() (x8D ]a  
        Open fileName For Input As fid 'zx1kq1  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) oedLe9!  
        Close fid \aGTi pB  
    End If HAGpM\Qa  
    Set oFSO = Nothing x4/f5  
    Return UBound( lineArray ) MOu=  
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End Function O`'r:&#W  
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Sub GetFileList( ByVal in_dir As String, _ *l8:%t\  
                 ByRef in_flist() As String ) f26hB;n  
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    'Redimension the file list array Qg gx:  
    Erase in_flist cp3O$S  
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    'Tracks how many files are found mI3 \n  
    Dim fCount As Long 7\Wq:<JL  
    fCount = 0 @x/D8HK2  
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    'Recurse directory and search for text files =LojRY  
    Dim f As String bLyaJ%pa\/  
    f = Dir$(in_dir & "*.txt") ,(Nr_K  
    While f <> "" nQ^ c{Bm:  
        ReDim Preserve in_flist(fCount) 629#t`W\  
        in_flist(fCount) = f ])$Rw$`w  
        fCount += 1 |Fp+9U  
        f = Dir$() tF~D!t@  
    Wend nY50dFA,  
    ReDim Preserve in_flist(fCount-1) P^& =L&U  
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End Sub "DU1k6XC