[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： U7fpaxc-  
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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。 1f^oW[w&  
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背景： *{5}m(5F  
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。 7ojh=imY  
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。 (421$w,B%  
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步骤 
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1、 在http://www.rpcphotonics.com/bsdf-data-optical-diffusers/下载并解压BSDF数据到某一文件夹下，选择“Raw data”文件。 Kg2@]J9m  
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2、 将     http://fred-kb.photonengr.com/wp-content/uploads/sites/2/2015/06/constructRpcScatterFile.frs脚本文件放在步骤1中的文件下。（脚本代码放在了本文的最后） lbIW1z%:sy  
3、 打开FRED并运行脚本文件，会输出如下“<SAMPLE>_FRED.txt”格式，<SAMPLE>即为RPC Photonics散射片数据集 u]B b^[  
例如下所示： EX<1hAw  
Sample name:  EDF-C1-56 .6n|hYe  
Merging data from file EDF-C1-56 0-0.txt J.2BB
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Finished merging RPC data for sample EDF-C1-56 E.$//P n|1  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt HWoMzp5="3  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 }1CO>a<  
a. 创建一个新的散射库 _kOuD}_|
 
b. 散射模型命名 Jnt r"a-4  
c. 改变散射模型为“Tabulated BSDF”. cQh{z8Bf?<  
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 ） $
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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。 [ui
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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，  KYccjX  
g. 点击OK @AG=Eq9<o  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 )tV]h#4  
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脚本代码： *Z"Kvj;>u  
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'#Language "WWB-COM" (o6u^#6  
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Option Explicit Rx%kAt2X  
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Sub Main QIN# \  
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    'Cleanup #lVSQZO~a  
    ClearOutputWindow() $[=`*m  
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    Print "Merging RPC Photonics BSDF Data Files" wL0"1Y
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    SetTextColor(255,0,0) gJOswN;([  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." jTQN(a9Y  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." b[;3y/X  
    SetTextColor(0,0,0) n |,}   
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    'Current directory of this script (should be the same as the text files being merged) 5o(=?dXm4  
    Dim cDir As String v g tJ+GjN  
    cDir = MacroDir$ & "\" ;rF:$37^  
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    'Array which will be populated with the list of files to be merged S 1Ji\  
    Dim fList() As String, curFile As String Q([g1?F9*  
    GetFileList( cDir, fList ) FUPJ&7+B  
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    Print "" Q;1$gImFz  
    Print "Files found for merging:" {24Pv#ZG#^  
    For Each curFile In fList 3^&pb  
        Print Chr(9) & curFile b;|^62  
    Next ]Otl(\v(h  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. }S&SL)  
    Dim nameArray() As String, sampName As String 9=~jKl%\vJ  
    nameArray = Split(fList(0)," 0-0.txt") ]zK} X!  
    sampName  = nameArray(0) F{<rIR  
    Print "" ~RE`@/wQ]  
    Print "Sample name: " & Chr(9) & sampName R?\8SdJ  
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    'Open an output file and write the FRED header data |y=D^NTG  
    Dim outFile As String r>q
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    outFile = cDir & sampName & "_FRED.txt" 4]8PF  
    Open outFile For Output As #1 7~`6~qg.  
    Print #1, "type bsdf_data" a. 5`Q2  
    Print #1, "format angles=deg bsdf=value scale=1" qOa-@
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    'Loop the file list, skip the two header lines and write the remaining data to file CnA*o 8w  
    Dim lineArray() As String, curLine As Long 7y`
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    For Each curFile In fList r*3XM{bZ/@  
        Print "Merging data from file " & curFile /ci.IT$Q^  
        ReadFile( cDir & curFile, lineArray ) Ap>n4~  
        For curLine = 2 To UBound(lineArray) AAl`bhx'n  
            Print #1, lineArray(curLine) gf@'d
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        Next sQH.}W$C  
    Next i|d41u;@  
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    'Close the output file 1X9sx&5H  
    Close #1 a+BA~|u^  
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    Print "Finished merging RPC data for sample " & sampName FRF}V@~  
    Print "FRED formatted data file: " & Chr(9) & outFile P?uKDON  
End Sub /iQ>he~fy  
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'Utility function to read the contents of a file into an array of strings. Rx<pV_|H,  
Function ReadFile(ByVal fileName As String, _ D 7E^;W)H  
                  ByRef lineArray() As String) As Long },L[bDOV07  
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    ReadFile = -1 G`W+m*[U+M  
    Dim oFSO As Object (jyJ-qe  
    Set oFSO = CreateObject("Scripting.FileSystemObject") \%^3Izsc  
    Erase lineArray q.X-2jjpx:  
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    Dim fid As Long |ZKchd8Yq  
    If oFSO.fileexists( fileName ) Then +[7u>RJ  
        fid = FreeFile() )T+htD)  
        Open fileName For Input As fid sR0nY8@F  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) ?{dno=  
        Close fid \5l}5<|  
    End If %?$"oWmenS  
    Set oFSO = Nothing ,J#5Y.  
    Return UBound( lineArray ) 1|89-Ii]  
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End Function /L8=8  
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Sub GetFileList( ByVal in_dir As String, _ [6tQv<}^
 
                 ByRef in_flist() As String ) j)5Vv K\  
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    'Redimension the file list array S{H8}m|MW  
    Erase in_flist }bTMeCgI  
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    'Tracks how many files are found uQNoIy J)  
    Dim fCount As Long tpctz~ .  
    fCount = 0 KKzvoc?Bt  
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    'Recurse directory and search for text files `F@yZ4L3S  
    Dim f As String M>#{
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    f = Dir$(in_dir & "*.txt") {Q"<q`c  
    While f <> "" o_5@R
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        ReDim Preserve in_flist(fCount) U|QDV16f  
        in_flist(fCount) = f -d~'tti  
        fCount += 1 a`uT'g[*  
        f = Dir$() /_|1,x-Kx  
    Wend #]'xUgcE9  
    ReDim Preserve in_flist(fCount-1) }R x%&29&  
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End Sub =EJ"edw]%0