[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： t8#u}u  
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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。 ?*f2P T?`  
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背景： 
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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。 |198A,^  
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。 Bh q]h  
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步骤 Bc?KAK  
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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。 8SO(pw9  
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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） =iWn T  
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 NMH'4R  
例如下所示： &>Nw>V  
Sample name:  EDF-C1-56 Y$eO:67;  
Merging data from file EDF-C1-56 0-0.txt U;Q?Rh-W  
Finished merging RPC data for sample EDF-C1-56 SGLU7*sfd  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt C.=[K_  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 `mDCX  
a. 创建一个新的散射库 Ob h@d|  
b. 散射模型命名 1>_2 =^[  
c. 改变散射模型为“Tabulated BSDF”. z~RE}k  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） +)e+$ l  
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。 .QM>^(o$Z  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， yH',vC.  
g. 点击OK p) m0\  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 /qPhptV  
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脚本代码： m}sh(W5\  
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'#Language "WWB-COM" F+m;y  
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Option Explicit sk~inIj-  
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Sub Main N|  
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    'Cleanup '"]U+aIg  
    ClearOutputWindow() Xny{8Oo<1?  
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    Print "Merging RPC Photonics BSDF Data Files" `:YCOF  
    SetTextColor(255,0,0) Na$[nv8qh  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." |aS272'  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." #b$qtp!,  
    SetTextColor(0,0,0) lWk/vj<5  
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    'Current directory of this script (should be the same as the text files being merged) +Z=DvKsTJ  
    Dim cDir As String cP>[H:\Xc  
    cDir = MacroDir$ & "\" |sPUb;&~  
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    'Array which will be populated with the list of files to be merged Ew*SA  
    Dim fList() As String, curFile As String . MH;u3U  
    GetFileList( cDir, fList ) kuW^_BROJ  
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    Print "" 6l&,!fd  
    Print "Files found for merging:" ~r?VXO p"  
    For Each curFile In fList `clp#l.ii  
        Print Chr(9) & curFile a<lDT_2b  
    Next 9}aEV 0 V|  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. Oc%W_Gb7  
    Dim nameArray() As String, sampName As String E{{Kzr2$  
    nameArray = Split(fList(0)," 0-0.txt") C,VvbB  
    sampName  = nameArray(0) P$*9Z@  
    Print "" ]Yk)A.y  
    Print "Sample name: " & Chr(9) & sampName b r\_  
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    'Open an output file and write the FRED header data EfGy^`,'G  
    Dim outFile As String ecyN};V>  
    outFile = cDir & sampName & "_FRED.txt" :*WiswMFm  
    Open outFile For Output As #1 #i=k-FA)H  
    Print #1, "type bsdf_data" <,,X\>B  
    Print #1, "format angles=deg bsdf=value scale=1" 40HhMTZ0-  
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    'Loop the file list, skip the two header lines and write the remaining data to file c]R27r E  
    Dim lineArray() As String, curLine As Long 3U%kf<m=  
    For Each curFile In fList |X;|=
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        Print "Merging data from file " & curFile >1RL5_US  
        ReadFile( cDir & curFile, lineArray ) V{n7KhN~Y!  
        For curLine = 2 To UBound(lineArray) %{&,5|8  
            Print #1, lineArray(curLine) -|
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        Next KRb'kW  
    Next a6\`r^@  
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    'Close the output file f-Zi!AGh>  
    Close #1 Ix+eP|8F  
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    Print "Finished merging RPC data for sample " & sampName Ik-E_U2  
    Print "FRED formatted data file: " & Chr(9) & outFile /cZTj!M  
End Sub 4|;Ys-Q  
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'Utility function to read the contents of a file into an array of strings. cc0Tb  
Function ReadFile(ByVal fileName As String, _ F(|XJN  
                  ByRef lineArray() As String) As Long DcN!u6sJ  
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    ReadFile = -1 _RE;}1rb,  
    Dim oFSO As Object C%H?vrR  
    Set oFSO = CreateObject("Scripting.FileSystemObject") 2])e}&i  
    Erase lineArray 3!vnSX(iv  
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    Dim fid As Long ; *\xdg{d  
    If oFSO.fileexists( fileName ) Then Sg*+!  
        fid = FreeFile() KkCsQ~po  
        Open fileName For Input As fid gF
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        lineArray = Split(Input(LOF(fid), fid), vbCrLf) {@hJPK8  
        Close fid YP>J'{?b*"  
    End If +QP(ATdM  
    Set oFSO = Nothing d .%2QkL  
    Return UBound( lineArray ) %F\.1\&eE  
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End Function /}9)ZYMx  
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Sub GetFileList( ByVal in_dir As String, _ $$i Gs6az  
                 ByRef in_flist() As String ) .q1y)l-^Z  
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    'Redimension the file list array j8c5_&  
    Erase in_flist ,0{x-S0jX<  
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    'Tracks how many files are found '}IGV`c  
    Dim fCount As Long YdyTt5-  
    fCount = 0 ZsSW{ffZ77  
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    'Recurse directory and search for text files @0(%ayi2Y  
    Dim f As String EvH/d4V;  
    f = Dir$(in_dir & "*.txt") @saK:z  
    While f <> "" #}l$<7ZU  
        ReDim Preserve in_flist(fCount) W8F@nY  
        in_flist(fCount) = f bOSqD[?  
        fCount += 1 =J|jCK[r  
        f = Dir$() .5);W;`X  
    Wend #8zC/u\`=  
    ReDim Preserve in_flist(fCount-1) %7QSBL  
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End Sub +\$c_9|C+