[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： -[G/2F'  
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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\*xaR.W  
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背景： jB*9 !xrd,  
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。 We[<BJo4  
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。 Tbe_xs^  
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步骤 pI'8>_o  
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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。 L+v8E/W  
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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） }T?i%l  
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 XMjI}SPG  
例如下所示： s#'|{  
Sample name:  EDF-C1-56 ]s1TJw [B  
Merging data from file EDF-C1-56 0-0.txt 9itdRa==  
Finished merging RPC data for sample EDF-C1-56 *uk\O]  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt 'e+-,CGdY\  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 !X \Sp}  
a. 创建一个新的散射库 4v rm&k  
b. 散射模型命名 $M:4\E5(  
c. 改变散射模型为“Tabulated BSDF”. aL_;`@4  
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 ） u.ULS3`C/X  
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。 + TPbIRA  
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， 6Y0/i,d*  
g. 点击OK @\
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5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 ucIVVT(u  
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脚本代码： z6GL,wo#  
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'#Language "WWB-COM" VWnu#_(  
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Option Explicit (E2lv#[  
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Sub Main O3slabE#
 
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    'Cleanup KD[)O7hYC  
    ClearOutputWindow() Zq2H9^![y~  
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    Print "Merging RPC Photonics BSDF Data Files" Jgi{7J  
    SetTextColor(255,0,0) $g}/T_26  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." UgOGBj,&5W  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." 'ugR!o1  
    SetTextColor(0,0,0) brpN>\  
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    'Current directory of this script (should be the same as the text files being merged) $S"zxEJJ Y  
    Dim cDir As String 'tq\<y
 
    cDir = MacroDir$ & "\" Zp% ""  
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    'Array which will be populated with the list of files to be merged (
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    Dim fList() As String, curFile As String Q@3ld6y  
    GetFileList( cDir, fList ) il`C,CD  
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    Print "" /_ hfjCE  
    Print "Files found for merging:" 3V8j>&  
    For Each curFile In fList l:kE^=6  
        Print Chr(9) & curFile (>)+;$Dr,\  
    Next K2vPj|  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. 7@e[:>e  
    Dim nameArray() As String, sampName As String A-@-?AR  
    nameArray = Split(fList(0)," 0-0.txt") Ed ?Yk* 4  
    sampName  = nameArray(0) MOH,'@&6^  
    Print "" unbcz{&Hb[  
    Print "Sample name: " & Chr(9) & sampName |eVTxeq  

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    'Open an output file and write the FRED header data "~i#9L/H  
    Dim outFile As String 6P/9Vh j'  
    outFile = cDir & sampName & "_FRED.txt" CO6XIgTe  
    Open outFile For Output As #1 *(XgUJq+  
    Print #1, "type bsdf_data" SquqaX+<  
    Print #1, "format angles=deg bsdf=value scale=1" }gi`?58J6  
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    'Loop the file list, skip the two header lines and write the remaining data to file 37<GG)  
    Dim lineArray() As String, curLine As Long \C'I l w  
    For Each curFile In fList vp9E}ga  
        Print "Merging data from file " & curFile _#\5]D~""  
        ReadFile( cDir & curFile, lineArray )  ZeDDH  
        For curLine = 2 To UBound(lineArray) oeU+?-y/b  
            Print #1, lineArray(curLine) sjVl/t`l  
        Next lfI7&d*  
    Next aX%g+6t2  
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    'Close the output file s$=B~l  
    Close #1 s#8{:ko  
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    Print "Finished merging RPC data for sample " & sampName WY ^K7U  
    Print "FRED formatted data file: " & Chr(9) & outFile E'6z7m.  
End Sub 0^tJX1L  
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'Utility function to read the contents of a file into an array of strings. 4QN6BZJ5  
Function ReadFile(ByVal fileName As String, _ LnACce ?b  
                  ByRef lineArray() As String) As Long =K&q;;h  
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    ReadFile = -1 /(}l[jf  
    Dim oFSO As Object s13 d*  
    Set oFSO = CreateObject("Scripting.FileSystemObject") e1Z;\U$&.  
    Erase lineArray _d"Y6 0  
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    Dim fid As Long PeR<FSF ,i  
    If oFSO.fileexists( fileName ) Then \?Oa}&k$F8  
        fid = FreeFile() iOA3x 8J  
        Open fileName For Input As fid c9TkIe  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) U
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        Close fid ^SES')x  
    End If =?QQb>  
    Set oFSO = Nothing ~o\]K  
    Return UBound( lineArray ) r'}k`A5>  
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End Function jq]\oY8y  
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Sub GetFileList( ByVal in_dir As String, _ JZ*?1S>  
                 ByRef in_flist() As String ) )I1V2k$n  
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    'Redimension the file list array /-} p7AM  
    Erase in_flist 3j
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    'Tracks how many files are found Ay. q
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    Dim fCount As Long OjL"0imN6  
    fCount = 0 ;@$,
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    'Recurse directory and search for text files Sv[_BP\^h  
    Dim f As String kO O~%|1CP  
    f = Dir$(in_dir & "*.txt") REe%>|   
    While f <> "" P) 0=@{(  
        ReDim Preserve in_flist(fCount) ;{#M  
        in_flist(fCount) = f D"><S<C\C  
        fCount += 1 U8@*I>vA  
        f = Dir$() XT;IEZQZ  
    Wend dXSb%ho  
    ReDim Preserve in_flist(fCount-1) ~<Qxw>S#  
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End Sub l<:)rg^,