[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： Dyt}"r\  
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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。 q'c'rN^  
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背景： ^(UL$cQ>  
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。 70|Cn(p_  
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。 &:'Uh W-t  
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步骤 iSIj ?.  
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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。 EkjO4=~UC  
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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）  b.C!4^  
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 10}\7p8  
例如下所示： Et`z7Q*e  
Sample name:  EDF-C1-56 |*OS;FD5  
Merging data from file EDF-C1-56 0-0.txt m./lrz  
Finished merging RPC data for sample EDF-C1-56 *PZNZ{|m  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt f5d"H6%L  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 {T m-X`  
a. 创建一个新的散射库 B{c,/{=O  
b. 散射模型命名 `){*JPl  
c. 改变散射模型为“Tabulated BSDF”. Os?~U/  
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 ） hofZpM  
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。 I&R4.;LW  
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， yy/wSk  
g. 点击OK Tfs7SC8ta  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 6^UeEmjc  
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脚本代码： Yz.[Cm
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'#Language "WWB-COM" M<g>z6   
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Option Explicit 5XA6IL|/l  
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Sub Main x1Z?x,-D"  
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    'Cleanup ?sp  
    ClearOutputWindow() !t~S.`
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    Print "Merging RPC Photonics BSDF Data Files" &[qLl  
    SetTextColor(255,0,0) F~{yqY5]n  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." '$q'Wl)  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." & UL(r  
    SetTextColor(0,0,0) XSn^$$S  
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    'Current directory of this script (should be the same as the text files being merged) C37KvLQ  
    Dim cDir As String \W}?4kz  
    cDir = MacroDir$ & "\" 73 D|gF*  
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    'Array which will be populated with the list of files to be merged ]}~*uT}>  
    Dim fList() As String, curFile As String xREqcH,vU  
    GetFileList( cDir, fList ) d!e$BiC  
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    Print "" !-LPFy>  
    Print "Files found for merging:" q ( H^H  
    For Each curFile In fList IkL|bV3E0  
        Print Chr(9) & curFile )uZ<?bkQ  
    Next )5Gzk&|  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. Ny p5=  
    Dim nameArray() As String, sampName As String :=UeYm @  
    nameArray = Split(fList(0)," 0-0.txt")  4\dc  
    sampName  = nameArray(0) {C|#<}1  
    Print "" %L<VnY#%u  
    Print "Sample name: " & Chr(9) & sampName V5qvH"^  
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    'Open an output file and write the FRED header data $zyY"yWRZ  
    Dim outFile As String )?I1*(1{A  
    outFile = cDir & sampName & "_FRED.txt" q8P| ]  
    Open outFile For Output As #1 WTSY:kvcCY  
    Print #1, "type bsdf_data" tiI>iP`!  
    Print #1, "format angles=deg bsdf=value scale=1" E;| q  
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    'Loop the file list, skip the two header lines and write the remaining data to file j}#48{  
    Dim lineArray() As String, curLine As Long <P(d%XEl  
    For Each curFile In fList EX=+TOkAf  
        Print "Merging data from file " & curFile ) ?+-Z2BwA  
        ReadFile( cDir & curFile, lineArray ) Xv9kJ  
        For curLine = 2 To UBound(lineArray) n"(n*Hf7b  
            Print #1, lineArray(curLine) `f8{^Rau  
        Next )=[K$>0k  
    Next u}qfwVX Z  
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    'Close the output file @X\Sh>H  
    Close #1 nBWrkVX  
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    Print "Finished merging RPC data for sample " & sampName S2;{)"mS  
    Print "FRED formatted data file: " & Chr(9) & outFile V.:a6>]  
End Sub DUM,dFIlvF  
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'Utility function to read the contents of a file into an array of strings. \02j~r`o  
Function ReadFile(ByVal fileName As String, _ < 5;0LPU  
                  ByRef lineArray() As String) As Long _ZC4O&fL  
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    ReadFile = -1 K:465r:  
    Dim oFSO As Object rV[#4,}PF  
    Set oFSO = CreateObject("Scripting.FileSystemObject") 8y/YX  
    Erase lineArray @@'zMV%  
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    Dim fid As Long 0F0V
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    If oFSO.fileexists( fileName ) Then A5F< <  
        fid = FreeFile() 'g|%Ro/  
        Open fileName For Input As fid q !EJs:AS  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) Rr|VGtg  
        Close fid ipw_AC~  
    End If @HMt}zD  
    Set oFSO = Nothing 0A9x9l9Wd  
    Return UBound( lineArray ) rRYP~ $c  
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End Function ^qIp+[/'  
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Sub GetFileList( ByVal in_dir As String, _ Yw\}'7  
                 ByRef in_flist() As String ) &&M-5XD  
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    'Redimension the file list array 5R{ {FD`h  
    Erase in_flist [WRs1$5  
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    'Tracks how many files are found 8}{';k  
    Dim fCount As Long @zT.&1;`  
    fCount = 0 ?*9U d  
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    'Recurse directory and search for text files iL/(WAB_od  
    Dim f As String 4)]g=-3  
    f = Dir$(in_dir & "*.txt") `[jQn;  
    While f <> "" ]6pxd \Q  
        ReDim Preserve in_flist(fCount) (=QaAn,,R  
        in_flist(fCount) = f \&&kUpI  
        fCount += 1 5#80`/w^U  
        f = Dir$() oZA|IF8U0  
    Wend G"5Nj3vd  
    ReDim Preserve in_flist(fCount-1) 5l=B,%s  
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End Sub LJc w->