[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： RWM~7^JA  
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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。
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背景： rttKj{7E  
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。 ,mCf{V]#  
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。 V#b*:E.cA  
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步骤 buzpmRoN)  
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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。 =M@)qy  
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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） \&V[<]  
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 /M]P&Zb |  
例如下所示： !(Y|Vm'  
Sample name:  EDF-C1-56 c; .y  
Merging data from file EDF-C1-56 0-0.txt .':17 $c`H  
Finished merging RPC data for sample EDF-C1-56 =w_T{V  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt j;j~R3B  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 Pk5\v0vkg  
a. 创建一个新的散射库 r SoT]6/   
b. 散射模型命名 FChW`b&S  
c. 改变散射模型为“Tabulated BSDF”. d1^5r 31  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） -Tuk.>i)  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 fIx|0,D&7L  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， O7Jp;  
g. 点击OK K|~!oQ  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 O@HD'  
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脚本代码： Z *l&<q>#  
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'#Language "WWB-COM" pG*W>F  
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Option Explicit BUh(pS:  
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Sub Main Z$Qwn  
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    'Cleanup OaN"6Ge#  
    ClearOutputWindow() 5
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    Print "Merging RPC Photonics BSDF Data Files" @
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    SetTextColor(255,0,0) 1Nv qtVC  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." 5?j#  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." ~^ '+.  
    SetTextColor(0,0,0) DYZk1  
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    'Current directory of this script (should be the same as the text files being merged) !,7)ZW?*8  
    Dim cDir As String |w_l~xYV)  
    cDir = MacroDir$ & "\" @v/Ae_q!  
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    'Array which will be populated with the list of files to be merged Je'%E
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    Dim fList() As String, curFile As String pnv)D}"  
    GetFileList( cDir, fList ) G&6`?1k  
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    Print "" ?6MUyH]a  
    Print "Files found for merging:" PEKXPFN  
    For Each curFile In fList mG*Yv  
        Print Chr(9) & curFile 4>HQ2S{t  
    Next cft@sY  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. YcSPU(  
    Dim nameArray() As String, sampName As String eM7F8j  
    nameArray = Split(fList(0)," 0-0.txt") ="g9>  
    sampName  = nameArray(0) #V[Os!ns  
    Print "" Fl==k  
    Print "Sample name: " & Chr(9) & sampName 1)-VlQK p  
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    'Open an output file and write the FRED header data =}+xD|T  
    Dim outFile As String e:QH3|'y  
    outFile = cDir & sampName & "_FRED.txt" sa"!ckh  
    Open outFile For Output As #1 Djp;\.$(  
    Print #1, "type bsdf_data" >(Wt  
    Print #1, "format angles=deg bsdf=value scale=1" b|.<rV'BTt  
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    'Loop the file list, skip the two header lines and write the remaining data to file N;cSR\Ng  
    Dim lineArray() As String, curLine As Long P$/Y9o  
    For Each curFile In fList G$lE0_j2{  
        Print "Merging data from file " & curFile sg<
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        ReadFile( cDir & curFile, lineArray ) /EVXkf0  
        For curLine = 2 To UBound(lineArray) /XuOv(j  
            Print #1, lineArray(curLine) .  
        Next TPi{c_ ]  
    Next [hiV#  
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    'Close the output file `P*PCiZos  
    Close #1 #<w2xR]:  
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    Print "Finished merging RPC data for sample " & sampName  7"])Y  
    Print "FRED formatted data file: " & Chr(9) & outFile *W4~.peoE  
End Sub Q6PMRG}/o  
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'Utility function to read the contents of a file into an array of strings. '81WogH:  
Function ReadFile(ByVal fileName As String, _ PW*[(VX  
                  ByRef lineArray() As String) As Long mGUG  
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    ReadFile = -1 R+=Xr<`%U|  
    Dim oFSO As Object `S]DHxS  
    Set oFSO = CreateObject("Scripting.FileSystemObject") 6?l|MU"Q.  
    Erase lineArray Ec!R3+  
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    Dim fid As Long Ke\FzZ]  
    If oFSO.fileexists( fileName ) Then Ehtb`Ms  
        fid = FreeFile() )dRBI)P  
        Open fileName For Input As fid 6"o@d8>v  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) 6[]O3Aa  
        Close fid v<]$,V]  
    End If G>+iisb%  
    Set oFSO = Nothing ZX40-6#O  
    Return UBound( lineArray ) 4~0@(3  
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End Function 'u%SI]*;>  
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Sub GetFileList( ByVal in_dir As String, _ D^H4]
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                 ByRef in_flist() As String ) R lmeZy4.  
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    'Redimension the file list array b5UIX Kim  
    Erase in_flist ^A t,x  
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    'Tracks how many files are found RV6|sN[x>  
    Dim fCount As Long t",b.vki\z  
    fCount = 0 y6Ea_v  
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    'Recurse directory and search for text files udX!R^8jE  
    Dim f As String 20BU;D3  
    f = Dir$(in_dir & "*.txt") @@+BPLl  
    While f <> "" 9*xv ,Yz8  
        ReDim Preserve in_flist(fCount) Ug^vVc)  
        in_flist(fCount) = f _n!W4zwi  
        fCount += 1 jsIT{a*]  
        f = Dir$() 95BRZ!ts  
    Wend bB
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    ReDim Preserve in_flist(fCount-1) j{H
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End Sub kntn9G