[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： =D Tbz3<  
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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。 p:xVi0  
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背景： J+=?taZ  
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。 %[OZ;q& X  
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。 cHon' tS  
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步骤 z q@"qnr  
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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。 ,f$ftn\~j/  
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2、 将     http://fred-kb.photonengr.com/wp-content/uploads/sites/2/2015/06/constructRpcScatterFile.frs脚本文件放在步骤1中的文件下。（脚本代码放在了本文的最后） U98e=57N  
3、 打开FRED并运行脚本文件，会输出如下“<SAMPLE>_FRED.txt”格式，<SAMPLE>即为RPC Photonics散射片数据集 f`-UC_(;  
例如下所示： +THK Jn!>  
Sample name:  EDF-C1-56 O5ZR{f&  
Merging data from file EDF-C1-56 0-0.txt sV`p3L8pl  
Finished merging RPC data for sample EDF-C1-56 Rw|P$dbu  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt W_[ tdqey  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 YXDuhrs}  
a. 创建一个新的散射库 Na<);Pg  
b. 散射模型命名 Wux[h8G  
c. 改变散射模型为“Tabulated BSDF”. RP%FMb}nt  
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 ） qP72JxT  
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。 _*n 4W^8  
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， J#?z/3v(  
g. 点击OK |9]_<X[ic  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 a7"Aq:IjU  
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脚本代码： v8>bR|n5  
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'#Language "WWB-COM" '1b4nj|<m  
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Option Explicit Zo@  
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Sub Main Xn%O .yM6  
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    'Cleanup j5G=ZI86y  
    ClearOutputWindow() 7,FhKTV1/  
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    Print "Merging RPC Photonics BSDF Data Files" ilwIqj  
    SetTextColor(255,0,0) _c,{}sn  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." F87c?Vh)K  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." SEIJ+u9XsA  
    SetTextColor(0,0,0) I[bWd{i:  
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    'Current directory of this script (should be the same as the text files being merged) yo :63CPP  
    Dim cDir As String wS+j^ ;"  
    cDir = MacroDir$ & "\" Gq{);fq  
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    'Array which will be populated with the list of files to be merged om8`^P/b  
    Dim fList() As String, curFile As String +Os9}uKf  
    GetFileList( cDir, fList ) U|+c&TY
 
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    Print "" &p5^Cjy L  
    Print "Files found for merging:" )jm!^m  
    For Each curFile In fList 
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        Print Chr(9) & curFile EC7)M}H  
    Next q:9CFAX0=  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. \2M{R  
    Dim nameArray() As String, sampName As String !YX_k<1E  
    nameArray = Split(fList(0)," 0-0.txt") ,Gy2$mglB  
    sampName  = nameArray(0) KU;J2Kt  
    Print "" b 4A1M  
    Print "Sample name: " & Chr(9) & sampName [vOk=  
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    'Open an output file and write the FRED header data (;(2n;i[M  
    Dim outFile As String pV/5w<_x?  
    outFile = cDir & sampName & "_FRED.txt" r}-vOPn`E  
    Open outFile For Output As #1 _Q7]Dw/w\  
    Print #1, "type bsdf_data" `+@r0:G&v  
    Print #1, "format angles=deg bsdf=value scale=1" b?k6-r$j  
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    'Loop the file list, skip the two header lines and write the remaining data to file C#P7@JE  
    Dim lineArray() As String, curLine As Long VMw[M^  
    For Each curFile In fList JdX!#\O  
        Print "Merging data from file " & curFile E51S#T  
        ReadFile( cDir & curFile, lineArray ) o':K4r;  
        For curLine = 2 To UBound(lineArray) bZu2.?{  
            Print #1, lineArray(curLine) Vsd4;  
        Next vGchKN~_  
    Next Ted!*HKlB  
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    'Close the output file &0SgEUZr  
    Close #1 W$:D#;jz`h  
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    Print "Finished merging RPC data for sample " & sampName T*92o:^  
    Print "FRED formatted data file: " & Chr(9) & outFile 76b2 3|  
End Sub ~z7
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'Utility function to read the contents of a file into an array of strings. /@@?0xjX  
Function ReadFile(ByVal fileName As String, _ M\r=i>(cu  
                  ByRef lineArray() As String) As Long (>`S{L C>s  
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    ReadFile = -1 m.c2y6<=  
    Dim oFSO As Object 1l\.>H\E  
    Set oFSO = CreateObject("Scripting.FileSystemObject") ZV$!dHW/  
    Erase lineArray yDAvl+  
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    Dim fid As Long lQG;WVqW  
    If oFSO.fileexists( fileName ) Then _g6H&no[  
        fid = FreeFile() 2C#b-Y1~N  
        Open fileName For Input As fid )5w#n1  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) 8r48+_y3u  
        Close fid 0xUn#&A~  
    End If +5H1n(6)  
    Set oFSO = Nothing Z._%T$8aJv  
    Return UBound( lineArray ) )zu m.6pT  
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End Function bM"d$tl$?'  
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Sub GetFileList( ByVal in_dir As String, _ pPJE.[)V/  
                 ByRef in_flist() As String ) wPaM
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    'Redimension the file list array Qk].^'\  
    Erase in_flist s(y=u>  
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    'Tracks how many files are found wSG!.Ejc7  
    Dim fCount As Long 2cko GafG{  
    fCount = 0 a~F\2`Q  
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    'Recurse directory and search for text files o^+g2;Ro  
    Dim f As String +4V"&S|&  
    f = Dir$(in_dir & "*.txt") oFp4*<\  
    While f <> "" i?6#>;f  
        ReDim Preserve in_flist(fCount) Em/? 4&
 
        in_flist(fCount) = f +lw1v  
        fCount += 1 Je=k.pO1  
        f = Dir$() XT{ukEvDR  
    Wend 8HL8)G6  
    ReDim Preserve in_flist(fCount-1) (~]0)J  
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End Sub M~5Ja0N~