[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： q3-cWfU  
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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。 k%-UW%  
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背景： rTJU)4I^h  
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。 'Cz]p~oF  
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。 ^ yF Wvfh4  
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步骤 9!2$?xqym  
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1、 在http://www.rpcphotonics.com/bsdf-data-optical-diffusers/下载并解压BSDF数据到某一文件夹下，选择“Raw data”文件。 A]o3MoSt  
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2、 将     http://fred-kb.photonengr.com/wp-content/uploads/sites/2/2015/06/constructRpcScatterFile.frs脚本文件放在步骤1中的文件下。（脚本代码放在了本文的最后） \MmB+'f&R  
3、 打开FRED并运行脚本文件，会输出如下“<SAMPLE>_FRED.txt”格式，<SAMPLE>即为RPC Photonics散射片数据集 VzcW9'"#  
例如下所示： L+lye Ir'  
Sample name:  EDF-C1-56 K&=6DvfR  
Merging data from file EDF-C1-56 0-0.txt v] Xy^7?  
Finished merging RPC data for sample EDF-C1-56 y|9 LtQ  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt >%_i#|dE>  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 Kl(u~/=6  
a. 创建一个新的散射库 #0#
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b. 散射模型命名 jlUT9Zp  
c. 改变散射模型为“Tabulated BSDF”. abEdZ)$  
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 ） NB( G
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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。 RzLeR%O  
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， Av/y  
g. 点击OK q^@*k,HG  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 pf=CP%L  
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脚本代码： &,]yqG 2  
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'#Language "WWB-COM" ]tbl1=|  
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Option Explicit i.ivHV~-  
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Sub Main gvP.\,U  
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    'Cleanup kh>i#9Ie  
    ClearOutputWindow() '1\UFz  
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    Print "Merging RPC Photonics BSDF Data Files" ]}_Ohe]X  
    SetTextColor(255,0,0) =VZ0+Yl  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." xT+@0?|F  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." ).$kp
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    SetTextColor(0,0,0) g8Zf("  
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    'Current directory of this script (should be the same as the text files being merged) (*!4O>]  
    Dim cDir As String !t&C,@Ox  
    cDir = MacroDir$ & "\" <L3ig%#B  
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    'Array which will be populated with the list of files to be merged \&Oc}]  
    Dim fList() As String, curFile As String @#5?tk0  
    GetFileList( cDir, fList ) U }}E E~W  
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    Print "" S'AS,'EnY  
    Print "Files found for merging:" I{u+=0^Y  
    For Each curFile In fList _qS4Ns/4s  
        Print Chr(9) & curFile V%J_iY/BUb  
    Next Mj |"+(  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. BOW`{=  
    Dim nameArray() As String, sampName As String !f8]gTzN  
    nameArray = Split(fList(0)," 0-0.txt") k=5v J72U  
    sampName  = nameArray(0) J)=Ts({  
    Print "" 'jU;.vZex  
    Print "Sample name: " & Chr(9) & sampName K%>3ev=y.s  
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    'Open an output file and write the FRED header data T4"*w  
    Dim outFile As String YR68'Sft[  
    outFile = cDir & sampName & "_FRED.txt" t3aDDu  
    Open outFile For Output As #1 +0n,>eDjg^  
    Print #1, "type bsdf_data" dv\aP  
    Print #1, "format angles=deg bsdf=value scale=1" 6b=7{nLF  
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    'Loop the file list, skip the two header lines and write the remaining data to file
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    Dim lineArray() As String, curLine As Long 3VmF1w 2  
    For Each curFile In fList SV_b(wP9  
        Print "Merging data from file " & curFile ]Y6y ]u  
        ReadFile( cDir & curFile, lineArray ) =:v5` :  
        For curLine = 2 To UBound(lineArray) EoHrXv  
            Print #1, lineArray(curLine) IgtTYxI  
        Next fhQ}Z%$  
    Next l#%G~c8x  
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    'Close the output file jD'$nKpg  
    Close #1 uze5u\  
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    Print "Finished merging RPC data for sample " & sampName *6P)HU@  
    Print "FRED formatted data file: " & Chr(9) & outFile H}&4#CQ'!  
End Sub 4>I;^LHn  
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'Utility function to read the contents of a file into an array of strings. nM&UdKf3  
Function ReadFile(ByVal fileName As String, _ .ID9Xd$fky  
                  ByRef lineArray() As String) As Long /c-%+Xd  
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    ReadFile = -1 7e`h,e=  
    Dim oFSO As Object S?LUSb  
    Set oFSO = CreateObject("Scripting.FileSystemObject") @ Yzj  
    Erase lineArray Av^<_`L:  
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    Dim fid As Long 3k?|-js  
    If oFSO.fileexists( fileName ) Then \{M/Do:  
        fid = FreeFile() ]k.'~Syz  
        Open fileName For Input As fid cu$i8$?t  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) e`D?x1-  
        Close fid j+>&~
  
    End If AwO'%+Bv  
    Set oFSO = Nothing tR% &.,2  
    Return UBound( lineArray ) Cu+u'&U!  
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End Function :yC|Q)  
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Sub GetFileList( ByVal in_dir As String, _ 0}y-DCuQ  
                 ByRef in_flist() As String )
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    'Redimension the file list array /0I=?+QSo  
    Erase in_flist ZRo-=/1  
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    'Tracks how many files are found iKN800^u  
    Dim fCount As Long BY^5z<^.  
    fCount = 0 GLIP;)h1  
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    'Recurse directory and search for text files o@g/,V $  
    Dim f As String hz_F^gF  
    f = Dir$(in_dir & "*.txt") N:Zf4  
    While f <> "" 5uufpvah  
        ReDim Preserve in_flist(fCount) esVZ2_eL  
        in_flist(fCount) = f d8Kxtg Y  
        fCount += 1 /*yPy?  
        f = Dir$() SR\F2@u  
    Wend 9K`uGu  
    ReDim Preserve in_flist(fCount-1) ngHPOI16  
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End Sub nzK"eNDN.