[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： kj/v$m  
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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。 n#"N"6s  
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背景： O*udVE>  
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。
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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
  
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步骤 Kdr}7#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。 Rg%Xy`gS  
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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） -fT}Nj\  
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 X3R:^ff\  
例如下所示： }dpE>  
Sample name:  EDF-C1-56 bEB9J- Q  
Merging data from file EDF-C1-56 0-0.txt Xz\X 8I  
Finished merging RPC data for sample EDF-C1-56 Rgb&EnVW  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt rbc7CPq_^  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 7Y6b<:4j  
a. 创建一个新的散射库 }.N~jx0R  
b. 散射模型命名 V@pUU~6R  
c. 改变散射模型为“Tabulated BSDF”. Wiere0 2*  
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 ） $/"QYSF  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 NKMVp/66D  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， 'H-hp   
g. 点击OK Tl L\&n.$  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 2U&+K2  
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脚本代码： 6[\1Nzy>  
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'#Language "WWB-COM" {Lugdf'  
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Option Explicit ih(Al<IS  
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Sub Main to(lE2`.da  
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    'Cleanup =+w/t9I[  
    ClearOutputWindow() ~WKWx.ul  
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    Print "Merging RPC Photonics BSDF Data Files" j9f[){m`  
    SetTextColor(255,0,0) g5lK&-yu]  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." ?D['>Rzu  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." hq?F81  
    SetTextColor(0,0,0) {=6CL'_  
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    'Current directory of this script (should be the same as the text files being merged) R{UZCFZ  
    Dim cDir As String 6f)7*j~  
    cDir = MacroDir$ & "\" &Y1RPO41J  
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    'Array which will be populated with the list of files to be merged &"d :+!4h  
    Dim fList() As String, curFile As String H $mZ?  
    GetFileList( cDir, fList ) ;E0x#JUrw  
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    Print "" 8\rAx P}=  
    Print "Files found for merging:" /Nns3oE  
    For Each curFile In fList V\=%u<f  
        Print Chr(9) & curFile ^+x,211f  
    Next T@mYHKu  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. '#lc?Y(pJ2  
    Dim nameArray() As String, sampName As String T'a&  
    nameArray = Split(fList(0)," 0-0.txt") DaqlL  
    sampName  = nameArray(0) ]0=THq\H  
    Print "" \ESNfL5  
    Print "Sample name: " & Chr(9) & sampName zqxN/H]z  
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    'Open an output file and write the FRED header data aB{OXU}#  
    Dim outFile As String 0u bf]Z  
    outFile = cDir & sampName & "_FRED.txt" \qJ cs'D  
    Open outFile For Output As #1 BO0Y#fs  
    Print #1, "type bsdf_data" \jr-^n]  
    Print #1, "format angles=deg bsdf=value scale=1" .F3~eas  
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    'Loop the file list, skip the two header lines and write the remaining data to file FpZ5@  
    Dim lineArray() As String, curLine As Long vdd>\r)v  
    For Each curFile In fList K~+x@O*  
        Print "Merging data from file " & curFile ! q+>'Mt  
        ReadFile( cDir & curFile, lineArray ) Iv/h1j> H  
        For curLine = 2 To UBound(lineArray) ekd;sEO  
            Print #1, lineArray(curLine) f{U,kCv  
        Next Ict+|<f  
    Next 7-mo\jw<  
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    'Close the output file 8#IEE|1  
    Close #1 c 6/lfgN  
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    Print "Finished merging RPC data for sample " & sampName M $zt;7P|  
    Print "FRED formatted data file: " & Chr(9) & outFile x$KQ*P~q  
End Sub j.:f=`xf  
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'Utility function to read the contents of a file into an array of strings. 06I(01M1  
Function ReadFile(ByVal fileName As String, _ !L)yI#i4C  
                  ByRef lineArray() As String) As Long m Gx{Vpt  
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    ReadFile = -1 ,irc=
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    Dim oFSO As Object 0G3T.4I  
    Set oFSO = CreateObject("Scripting.FileSystemObject") {
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    Erase lineArray sI@kS^  
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    Dim fid As Long Tj=@5lj0  
    If oFSO.fileexists( fileName ) Then 1p
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        fid = FreeFile() zwK$ q=-:  
        Open fileName For Input As fid iOiXo6YE  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) Z|j\_VKhl  
        Close fid 9g7Ok9dF  
    End If 1~[GGl  
    Set oFSO = Nothing h8P_/.+g|V  
    Return UBound( lineArray ) Rk}=SB-  
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End Function LP) IL~  
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Sub GetFileList( ByVal in_dir As String, _ fa,;Sw  
                 ByRef in_flist() As String ) \oO&c  
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    'Redimension the file list array 'h 7n}  
    Erase in_flist f0g&=k{OD  
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    'Tracks how many files are found n yNHjn |W  
    Dim fCount As Long q[+V6n`Z5  
    fCount = 0 cd$,,  
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    'Recurse directory and search for text files &sGLm~m#  
    Dim f As String /_r{7Gq.  
    f = Dir$(in_dir & "*.txt") C12y_E8Un  
    While f <> "" EiWd =jDm  
        ReDim Preserve in_flist(fCount) s_76)7  
        in_flist(fCount) = f uQkQ#'e|  
        fCount += 1 E /V`NqC  
        f = Dir$() Y4*?QBYA  
    Wend AmcBu"  
    ReDim Preserve in_flist(fCount-1) @fd
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End Sub 0vM,2:kf*