[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： ]Al;l*
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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。 lVH<lp_ZtK  
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背景： or ;f&![w  
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。 ?@6b>='!  
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。 SJ' % ^  
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步骤 Vsq8H}K  
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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。 G)=HB7u[a  
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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） p 5u_1U0  
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 kQdt}o])  
例如下所示： V)o,1  
Sample name:  EDF-C1-56 6&v?)o  
Merging data from file EDF-C1-56 0-0.txt 0CvsvUN@  
Finished merging RPC data for sample EDF-C1-56 vy@rQC %9  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt v"u^M-_  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 UnWW/]E  
a. 创建一个新的散射库 r~[vaQQ6L  
b. 散射模型命名 $e%2t^ i.g  
c. 改变散射模型为“Tabulated BSDF”. 1-SVCk -  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） 8am`6;O:!  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 @* 1U{`  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， &FdWFt=X  
g. 点击OK ye6H*K  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 Ru!He,k7  
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脚本代码： D.!~dyI.,$  
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'#Language "WWB-COM" PrF}a<:n:  
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Option Explicit UO`;&e-DB  
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Sub Main i yYJR  
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    'Cleanup z~6y+  
    ClearOutputWindow() 1xyU  
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    Print "Merging RPC Photonics BSDF Data Files" w-B^ [<  
    SetTextColor(255,0,0) \b8sG"G  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." iItcN;;7  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." =iB,["s  
    SetTextColor(0,0,0) YO)$M-]>%J  
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    'Current directory of this script (should be the same as the text files being merged) V5}nOGV9  
    Dim cDir As String 7
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    cDir = MacroDir$ & "\" `D7C?M#j]  
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    'Array which will be populated with the list of files to be merged bte~c  
    Dim fList() As String, curFile As String .@ C{3$,VG  
    GetFileList( cDir, fList ) l2%bF8]z  
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    Print "" 4o:hyh   
    Print "Files found for merging:" FX<b:#  
    For Each curFile In fList _GQz!YA  
        Print Chr(9) & curFile NMO-u3<6.  
    Next MjfFf} @  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. 3q[WHwmm  
    Dim nameArray() As String, sampName As String 1iT\df  
    nameArray = Split(fList(0)," 0-0.txt") gJt`?8t  
    sampName  = nameArray(0) Bc-yxjsw  
    Print "" aMARZ)V  
    Print "Sample name: " & Chr(9) & sampName stl 1QO(h  
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    'Open an output file and write the FRED header data _STB$cZ  
    Dim outFile As String ExSe=4q#  
    outFile = cDir & sampName & "_FRED.txt" +!-~yf#RE  
    Open outFile For Output As #1 F,Xo|jjj  
    Print #1, "type bsdf_data" \b'xt  
    Print #1, "format angles=deg bsdf=value scale=1" u D 5%E7  
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    'Loop the file list, skip the two header lines and write the remaining data to file 0XwHP{XaO  
    Dim lineArray() As String, curLine As Long fyz nuUl  
    For Each curFile In fList `+lHeLz':  
        Print "Merging data from file " & curFile g3@Rl2yQJ  
        ReadFile( cDir & curFile, lineArray ) a>4uiFiv  
        For curLine = 2 To UBound(lineArray) nm$Dd~mxW1  
            Print #1, lineArray(curLine) 7fp(R&)1  
        Next ln*icaDqf  
    Next x)rlyjFM  
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    'Close the output file hli|B+:m"  
    Close #1 q"KnLA(  
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    Print "Finished merging RPC data for sample " & sampName xieP "6  
    Print "FRED formatted data file: " & Chr(9) & outFile Hs"(@eDV&J  
End Sub $$i.O}  
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'Utility function to read the contents of a file into an array of strings. I|oT0y&  
Function ReadFile(ByVal fileName As String, _ <HWS:'1  
                  ByRef lineArray() As String) As Long S,fCV~Cio?  
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    ReadFile = -1 ,iNv'  
    Dim oFSO As Object n6WY&1ZE~  
    Set oFSO = CreateObject("Scripting.FileSystemObject") wo2@hav  
    Erase lineArray )|j[uh6wo  
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    Dim fid As Long 5/",<1  
    If oFSO.fileexists( fileName ) Then e[u?_h  
        fid = FreeFile() foF19_2 ,  
        Open fileName For Input As fid }*]B-\>  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) 14eW4~Mr  
        Close fid uaw~r2  
    End If kEeo5XN  
    Set oFSO = Nothing pnyWcrBf  
    Return UBound( lineArray ) dBsX*}C  
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End Function lA!"z~03*  
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Sub GetFileList( ByVal in_dir As String, _ f8 /'%$N  
                 ByRef in_flist() As String ) snM Z0W  
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    'Redimension the file list array MfF~8  
    Erase in_flist [$(%dV6O  
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    'Tracks how many files are found -Ue$T{;RoH  
    Dim fCount As Long Z0!5d<  
    fCount = 0 2'jOP"G  
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    'Recurse directory and search for text files y
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    Dim f As String 5 *}R$  
    f = Dir$(in_dir & "*.txt") <Tw>|cFT  
    While f <> ""
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        ReDim Preserve in_flist(fCount) KT|R
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        in_flist(fCount) = f MiT}L  
        fCount += 1 vgt]:$  
        f = Dir$() c:S] R"  
    Wend ]G.%Ty  
    ReDim Preserve in_flist(fCount-1) 'k;4j|<  
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End Sub XLk<*0tp