[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： .2e1S{9  
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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。 'nMApPl  
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背景： U);OR  
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。 -<_7\09  
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。 Q4X7Iu:  
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步骤 _WKJ<dB<  
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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。 2A*/C7
 
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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） R8tF/dx>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 eK9TAW  
例如下所示： Qu`n&  
Sample name:  EDF-C1-56 VMx%1^/(  
Merging data from file EDF-C1-56 0-0.txt gC`)]*'tE  
Finished merging RPC data for sample EDF-C1-56 wy''tqg6  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt 9UP:J0 `  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 s|Zx(.EP  
a. 创建一个新的散射库 }&1Iyb  
b. 散射模型命名 P<u"97@8a  
c. 改变散射模型为“Tabulated BSDF”. s;J\Kc?"|  
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 ） va5FxF*%  
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。 }w@gj"\H  
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， rR]-
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g. 点击OK k^^:;OR  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 6yI}1g  
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脚本代码： a+41Ojv (  
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'#Language "WWB-COM" ZW*n /#GUC  
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Option Explicit ~s#e,Kav"  
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Sub Main =MC~GXJSNw  
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    'Cleanup =OYQM<q  
    ClearOutputWindow() Fd7*]a  
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    Print "Merging RPC Photonics BSDF Data Files" c&f y{}10  
    SetTextColor(255,0,0) h>wcT VF  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." <*
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    Print "Note: Do not run this script multiple times without deleting the output file between executions." .Pw%DZ'  
    SetTextColor(0,0,0) PKA }zZ  
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    'Current directory of this script (should be the same as the text files being merged) Kd3QqVJBz1  
    Dim cDir As String Q.k :\m*h  
    cDir = MacroDir$ & "\" )p8I@E  
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    'Array which will be populated with the list of files to be merged 1zjaR4Tf  
    Dim fList() As String, curFile As String . uR M{Bs  
    GetFileList( cDir, fList ) =XT)J6z^"  
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    Print "" aV>aiR=  
    Print "Files found for merging:" ?} (=  
    For Each curFile In fList TJaeQqob  
        Print Chr(9) & curFile st/n"HQ  
    Next e"Rm_t  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. zX kx7d8  
    Dim nameArray() As String, sampName As String =MLf[
 
    nameArray = Split(fList(0)," 0-0.txt") h1+hds+  
    sampName  = nameArray(0) q* !3C  
    Print "" H9` f0(H  
    Print "Sample name: " & Chr(9) & sampName LK}-lZ` i  
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    'Open an output file and write the FRED header data * OsU Y=;  
    Dim outFile As String '<@=vGsye  
    outFile = cDir & sampName & "_FRED.txt" &Y7C0v  
    Open outFile For Output As #1 ^Y04qeRd  
    Print #1, "type bsdf_data" *Msr15  
    Print #1, "format angles=deg bsdf=value scale=1" 6;oe=Q
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    'Loop the file list, skip the two header lines and write the remaining data to file ~p*1:ij  
    Dim lineArray() As String, curLine As Long ;=jr0\|e  
    For Each curFile In fList V5"HwN+`  
        Print "Merging data from file " & curFile 6)e5zKW!?  
        ReadFile( cDir & curFile, lineArray ) 0JY WrPR  
        For curLine = 2 To UBound(lineArray) @Bs0Avj.  
            Print #1, lineArray(curLine) R$m`Z+/@  
        Next $/_qE  
    Next "tu*YNP\Q  
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    'Close the output file ^#e~g/  
    Close #1 op7FZHs  
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    Print "Finished merging RPC data for sample " & sampName g4&jo_3:p  
    Print "FRED formatted data file: " & Chr(9) & outFile wJG$c-(\0  
End Sub *P2[qhP2  
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'Utility function to read the contents of a file into an array of strings. K:r\{#9  
Function ReadFile(ByVal fileName As String, _ ~ 3T,&?r  
                  ByRef lineArray() As String) As Long |(% u}V?  
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    ReadFile = -1 ULBg{e?l8  
    Dim oFSO As Object A6UO0lyu  
    Set oFSO = CreateObject("Scripting.FileSystemObject") RuAlB*  
    Erase lineArray .ve *Vp
  
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    Dim fid As Long w'ybbv{c  
    If oFSO.fileexists( fileName ) Then xiM&$<LpR  
        fid = FreeFile() p-$Cs _{Z  
        Open fileName For Input As fid or_+2aG  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) Z1,gtl ?  
        Close fid
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    End If +=P@HfVfiq  
    Set oFSO = Nothing gPEqjj  
    Return UBound( lineArray ) ;-@=  
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End Function 7*+TP~WI  
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Sub GetFileList( ByVal in_dir As String, _ JlZ0n;  
                 ByRef in_flist() As String ) ]tt} #  
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    'Redimension the file list array kv?|'DN  
    Erase in_flist n:#TOU1ix<  
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    'Tracks how many files are found 3]LN;s]ac  
    Dim fCount As Long TEVI'%F
  
    fCount = 0 <94G  
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    'Recurse directory and search for text files m(47s  
    Dim f As String TI9X.E?
 
    f = Dir$(in_dir & "*.txt") pGWA\}'  
    While f <> "" Rp.W,)i  
        ReDim Preserve in_flist(fCount) f_6`tq m%  
        in_flist(fCount) = f ]]uHM}l  
        fCount += 1 [ygF0-3ND  
        f = Dir$() w2"]Pl  
    Wend x:z0EYL  
    ReDim Preserve in_flist(fCount-1) /i
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End Sub UTk r.T+2X