[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： Fxv~;o#  
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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。 e[915Q_  
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背景： s26s:A3rh  
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。 Gpe h#Q4x  
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。 f`WmRx]K  
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步骤 R(pvUm&L  
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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。 <%pi*:E|  
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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） aeSy,:  
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 ]o,)#/' $  
例如下所示： s_`wLQ7e  
Sample name:  EDF-C1-56 HaB=nLAT  
Merging data from file EDF-C1-56 0-0.txt EW2e k^  
Finished merging RPC data for sample EDF-C1-56 U0jq.]P  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt 5Odi\SJ&  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 a^Zn }R r  
a. 创建一个新的散射库 3w{i5gGn  
b. 散射模型命名
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c. 改变散射模型为“Tabulated BSDF”.
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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 ） \,p)  
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。  Kn\Oj=4  
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， C6'[Tn  
g. 点击OK  PJkMn  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值  J|6aa  
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脚本代码： f_raICO{R  
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'#Language "WWB-COM" ]
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Option Explicit kP8Ypw&  
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Sub Main db#y]>^l  
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    'Cleanup krz@1[w-j  
    ClearOutputWindow() Fzu"&&>0$  
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    Print "Merging RPC Photonics BSDF Data Files" S'3l<sY  
    SetTextColor(255,0,0) ;Kkn7&'F  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." ;2dhue  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." a |z{Bb  
    SetTextColor(0,0,0) |dX#4Mq^,  
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    'Current directory of this script (should be the same as the text files being merged) 1Ll@ ocE  
    Dim cDir As String xZ,g6s2o  
    cDir = MacroDir$ & "\" .'.|s?s  
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    'Array which will be populated with the list of files to be merged I"@5=m5  
    Dim fList() As String, curFile As String b;x^>(It  
    GetFileList( cDir, fList ) d>vGx  
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    Print "" KbwWrf>  
    Print "Files found for merging:" %f{
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    For Each curFile In fList zyCl`r[}  
        Print Chr(9) & curFile xTAC&OCk^[  
    Next U4LOe}Ny  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. |
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    Dim nameArray() As String, sampName As String evszfCH'J  
    nameArray = Split(fList(0)," 0-0.txt") vNJ!i\bX  
    sampName  = nameArray(0) `86 9XE  
    Print "" kTC6fNj[  
    Print "Sample name: " & Chr(9) & sampName GhpH7%s  
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    'Open an output file and write the FRED header data :Z=A,G  
    Dim outFile As String VnIJ$5Y  
    outFile = cDir & sampName & "_FRED.txt" t5eux&C  
    Open outFile For Output As #1 ~@sx}u  
    Print #1, "type bsdf_data" `7N[rs9|S  
    Print #1, "format angles=deg bsdf=value scale=1" 8Cm^#S,+  
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    'Loop the file list, skip the two header lines and write the remaining data to file })"9TfC  
    Dim lineArray() As String, curLine As Long RqcX_x(p  
    For Each curFile In fList @p
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        Print "Merging data from file " & curFile fMLm_5(H  
        ReadFile( cDir & curFile, lineArray ) :&TOQ<vM  
        For curLine = 2 To UBound(lineArray) ]@WJ&e/'@  
            Print #1, lineArray(curLine) @~a52'\  
        Next gL}K84T$S  
    Next #j;&g1  
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    'Close the output file $>#PhOC  
    Close #1 /{qr~7k,oQ  
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    Print "Finished merging RPC data for sample " & sampName o
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    Print "FRED formatted data file: " & Chr(9) & outFile eKLxNw5  
End Sub //6m2a  
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'Utility function to read the contents of a file into an array of strings. OwDjUKeN  
Function ReadFile(ByVal fileName As String, _ b/S4b  
                  ByRef lineArray() As String) As Long Rmd;ug9  
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    ReadFile = -1 }-8K*A3  
    Dim oFSO As Object q+LjWZ+O  
    Set oFSO = CreateObject("Scripting.FileSystemObject") Ye(0'*-jyc  
    Erase lineArray Lw!@[;2  
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    Dim fid As Long VMtR4!:q  
    If oFSO.fileexists( fileName ) Then $wX5`d1  
        fid = FreeFile() wmT3 >  
        Open fileName For Input As fid Grw_SVa^  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) !5=3Y4bg1  
        Close fid fh,Y#.V`  
    End If %7V?7BE  
    Set oFSO = Nothing $RF"m"  
    Return UBound( lineArray ) Is88+,O  
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End Function TJO|{Lxm  
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Sub GetFileList( ByVal in_dir As String, _
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                 ByRef in_flist() As String ) sY1*WolA  
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    'Redimension the file list array s'5 jvlG  
    Erase in_flist $]%k <|X  
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    'Tracks how many files are found eL-92]]e  
    Dim fCount As Long *!nS4
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    fCount = 0 3HfT9  
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    'Recurse directory and search for text files sQt@B#;  
    Dim f As String dn5T7a~   
    f = Dir$(in_dir & "*.txt") d5u,x.R  
    While f <> "" bg 7b!t1F  
        ReDim Preserve in_flist(fCount) 7G
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        in_flist(fCount) = f 4V[+
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        fCount += 1 1zl@$ Nt  
        f = Dir$() @o>2:D1G  
    Wend tM!1oWH  
    ReDim Preserve in_flist(fCount-1) G%4vZPA  
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End Sub c{&sf y