[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： x\YVB',h  
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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。 DH:9iX'  
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背景： :c(#03w*C  
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。 !wKiMgLS  
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。 (*\y  
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步骤 Is9.A_0h  
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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。 Bk5ft4v-  
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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） ^cuH\&&7  
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 {*nE8+..A  
例如下所示： 4G RHvA.  
Sample name:  EDF-C1-56 Ii>#
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Merging data from file EDF-C1-56 0-0.txt Omph(
  
Finished merging RPC data for sample EDF-C1-56 [YJ*zO  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt V>ZDJW"G!  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 >]2^5C;  
a. 创建一个新的散射库 @.pr}S/  
b. 散射模型命名 jH<,dG:{  
c. 改变散射模型为“Tabulated BSDF”. LYTnMrM  
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 ） kD6Iz$tr  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 bn
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f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， ".?y!VY  
g. 点击OK
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5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 GqgJ]m  
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脚本代码： y|3!E>Up  
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'#Language "WWB-COM" |RDE/  
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Option Explicit _,w*Rv5=  
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Sub Main =.,XJIw&  
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    'Cleanup Z 2lX^z  
    ClearOutputWindow() A[f`xE  
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    Print "Merging RPC Photonics BSDF Data Files" N8X)/W  
    SetTextColor(255,0,0) B9'2$s+Z;  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." mOFp!(  
    Print "Note: Do not run this script multiple times without deleting the output file between executions."
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    SetTextColor(0,0,0) G
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    'Current directory of this script (should be the same as the text files being merged) iu{QHjZK(  
    Dim cDir As String <XzRRCYQ  
    cDir = MacroDir$ & "\" )7Oj  
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    'Array which will be populated with the list of files to be merged Qd}h:U^  
    Dim fList() As String, curFile As String 5'EoB^`8N~  
    GetFileList( cDir, fList ) pWKI^S  
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    Print "" T? ,Q=.  
    Print "Files found for merging:" P+,YWp  
    For Each curFile In fList nDNK}O~'  
        Print Chr(9) & curFile >,f5 5  
    Next E%$[*jZ  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. 7s;*vd>  
    Dim nameArray() As String, sampName As String t<cWMx5ra  
    nameArray = Split(fList(0)," 0-0.txt") pzU:AUW  
    sampName  = nameArray(0) F^Mt}`O  
    Print "" +Xmza8T9  
    Print "Sample name: " & Chr(9) & sampName v&`n}lS  

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    'Open an output file and write the FRED header data GA.cp*2~  
    Dim outFile As String +^a@U^V  
    outFile = cDir & sampName & "_FRED.txt" RI]x=  
    Open outFile For Output As #1 Hlj3z3  
    Print #1, "type bsdf_data" P}-S[[b73s  
    Print #1, "format angles=deg bsdf=value scale=1" '@#l/9
 
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    'Loop the file list, skip the two header lines and write the remaining data to file PH!rWR  
    Dim lineArray() As String, curLine As Long yI's=Iu`  
    For Each curFile In fList R#/0}+-M  
        Print "Merging data from file " & curFile 'he&h4fm  
        ReadFile( cDir & curFile, lineArray ) kFi=^#J{  
        For curLine = 2 To UBound(lineArray) P2 +^7x?  
            Print #1, lineArray(curLine) /-g%IeF  
        Next Chtls;Ph[  
    Next mMad1qCi7  
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    'Close the output file JwUz4  
    Close #1 g+=f=5I3  
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    Print "Finished merging RPC data for sample " & sampName wodff_l  
    Print "FRED formatted data file: " & Chr(9) & outFile MUp{2_RA  
End Sub a6g+"EcH#'  
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'Utility function to read the contents of a file into an array of strings. ] -G~  
Function ReadFile(ByVal fileName As String, _ QC+BEN$  
                  ByRef lineArray() As String) As Long d C6t+  
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    ReadFile = -1 <2PO3w?Z  
    Dim oFSO As Object Yk5Cyq  
    Set oFSO = CreateObject("Scripting.FileSystemObject") lAx8m't}6  
    Erase lineArray h>n<5{zqM  
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    Dim fid As Long R?l={N=Wf  
    If oFSO.fileexists( fileName ) Then 0EUC8Ni  
        fid = FreeFile() yzz(<s:o/  
        Open fileName For Input As fid s=)1:jYk  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) |A:+[35  
        Close fid m[&pR2T  
    End If |z.Ov&d4)(  
    Set oFSO = Nothing 9jrlB0  
    Return UBound( lineArray ) !,;/JxfgVh  
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End Function )>WSuf j  
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Sub GetFileList( ByVal in_dir As String, _ ]q@W(
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                 ByRef in_flist() As String ) !*=+E%7  
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    'Redimension the file list array M!]g36h[  
    Erase in_flist :JG2xtn  
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    'Tracks how many files are found 1&JB@F9
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    Dim fCount As Long mV'
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    fCount = 0 [214b=  
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    'Recurse directory and search for text files N`!=z++G  
    Dim f As String #W=H)6  
    f = Dir$(in_dir & "*.txt") Xq.GvZS`  
    While f <> "" PD@@4@^
 
        ReDim Preserve in_flist(fCount) 7a'@NgiGg  
        in_flist(fCount) = f R
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        fCount += 1 5\P3JoH:Yg  
        f = Dir$() 1$rrfg  
    Wend M9dUo7  
    ReDim Preserve in_flist(fCount-1) 8nHFNOv6  
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End Sub #wZBWTj.