[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： TMs
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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。 ,+9r/}K]/  
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背景： D.`\ ^a  
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。 o |iLBh$)  
FRED是美国Photon Engineering 公司开发的光学工程仿真软件，其在杂散光分析中独特的算法、高效的准确性，使其与其它同类产品相比更具优势。本案例我们重点讲述如何由RPC Photonics的BSDF数据转为FRED可识别的散射数据。 ]SgeZ07  
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步骤 qKC*jDW  
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1、 在http://www.rpcphotonics.com/bsdf-data-optical-diffusers/下载并解压BSDF数据到某一文件夹下，选择“Raw data”文件。 yFsXI0I[p  
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2、 将     http://fred-kb.photonengr.com/wp-content/uploads/sites/2/2015/06/constructRpcScatterFile.frs脚本文件放在步骤1中的文件下。（脚本代码放在了本文的最后） Z+(V \  
3、 打开FRED并运行脚本文件，会输出如下“<SAMPLE>_FRED.txt”格式，<SAMPLE>即为RPC Photonics散射片数据集 7d)' y  
例如下所示： pa-4|)qY  
Sample name:  EDF-C1-56 1+($"$ZC&B  
Merging data from file EDF-C1-56 0-0.txt -+|[0hpw  
Finished merging RPC data for sample EDF-C1-56 Kf~+jYobO  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt V0i$"|F+E  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 AAgA]OD,  
a. 创建一个新的散射库 fM.|#eLi  
b. 散射模型命名 pSFWNWQ'B  
c. 改变散射模型为“Tabulated BSDF”. F2'cL@E3  
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 ） Al}PJz\  
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。 l.l~K%P'h  
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， t@M] ec  
g. 点击OK Lm#d.AD)  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 926oM77  
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脚本代码： yfQE8v+  
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'#Language "WWB-COM" MGDv4cFE.  
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Option Explicit BxYA[#fd}  
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Sub Main |>GIPfVT  
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    'Cleanup 8f5^@K\c  
    ClearOutputWindow() DjvgKy=Jr_  
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    Print "Merging RPC Photonics BSDF Data Files" 8Oh3iO  
    SetTextColor(255,0,0) ;jI"|v{vnS  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." S\gP=.G  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." u_=y,~s  
    SetTextColor(0,0,0) ZNeqsN{  
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    'Current directory of this script (should be the same as the text files being merged) ~1sl.8tF  
    Dim cDir As String f om"8iL1  
    cDir = MacroDir$ & "\" >]8.xkQq  
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    'Array which will be populated with the list of files to be merged rxeXz<  
    Dim fList() As String, curFile As String JZxF)]^  
    GetFileList( cDir, fList ) tuV?:g?  
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    Print "" 5V8C+k)  
    Print "Files found for merging:" 5>Yd\(`K  
    For Each curFile In fList ?<^AXLiKV  
        Print Chr(9) & curFile -wMW@:M_  
    Next [{LnE:  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. ld:alEo  
    Dim nameArray() As String, sampName As String ?
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    nameArray = Split(fList(0)," 0-0.txt") z}&C(m:al  
    sampName  = nameArray(0) 9yw/-nA  
    Print "" }px]  
    Print "Sample name: " & Chr(9) & sampName TFDCo_>o  
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    'Open an output file and write the FRED header data $50"3g!Y  
    Dim outFile As String +J8/,d  
    outFile = cDir & sampName & "_FRED.txt" $!
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    Open outFile For Output As #1 f<p4Pkv  
    Print #1, "type bsdf_data" q'@Ei4  
    Print #1, "format angles=deg bsdf=value scale=1" BG0Mj2  
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    'Loop the file list, skip the two header lines and write the remaining data to file b7sE  
    Dim lineArray() As String, curLine As Long |hQ|'VCN  
    For Each curFile In fList C-^%g[#  
        Print "Merging data from file " & curFile 1y-lZ}s_  
        ReadFile( cDir & curFile, lineArray ) B&kT#  
        For curLine = 2 To UBound(lineArray) )pn7DIXG  
            Print #1, lineArray(curLine) nYt\e]3  
        Next -7z y  
    Next U]U)'  
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    'Close the output file gLMea:  
    Close #1 fB,1s}3Hn  
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    Print "Finished merging RPC data for sample " & sampName )-:eQ{st`  
    Print "FRED formatted data file: " & Chr(9) & outFile *@n3>$  
End Sub VN-#R=D  
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'Utility function to read the contents of a file into an array of strings. q&d&#3Rh  
Function ReadFile(ByVal fileName As String, _ 'L|GClc6)
 
                  ByRef lineArray() As String) As Long giPo;z\c  
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    ReadFile = -1 [aZ v?Z  
    Dim oFSO As Object t^_{5  
    Set oFSO = CreateObject("Scripting.FileSystemObject") .>64h H  
    Erase lineArray A~GtK\=;  
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    Dim fid As Long lH@
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    If oFSO.fileexists( fileName ) Then _Z66[T+M  
        fid = FreeFile() !:O/|.+Vmf  
        Open fileName For Input As fid f,HzrHax  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) m9<%v0r  
        Close fid }8F$& AFt  
    End If %3c|  
    Set oFSO = Nothing H"q`k5R  
    Return UBound( lineArray ) hp]ng!I{\u  
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End Function qz=#;&ZU  
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Sub GetFileList( ByVal in_dir As String, _ <\d|=>;  
                 ByRef in_flist() As String ) <.=#EV^i  
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    'Redimension the file list array k#Ez  
    Erase in_flist gAr`hXO  
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    'Tracks how many files are found 3q|cZQK!1  
    Dim fCount As Long cR=94i=t  
    fCount = 0 4%!{?[$  
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    'Recurse directory and search for text files Y7kb1UG  
    Dim f As String !&a;P,_Fb  
    f = Dir$(in_dir & "*.txt") \n*7#aX/  
    While f <> "" N;x<| %peL  
        ReDim Preserve in_flist(fCount) ^?s~Fk_V  
        in_flist(fCount) = f ^#BGA|j  
        fCount += 1 Z`oaaO
 
        f = Dir$() &8Jg9#  
    Wend /K,|k EE'n  
    ReDim Preserve in_flist(fCount-1) n-hvh-ZO  
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End Sub O@r.>