[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： :y2p@#l#  
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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。 ^Cv^yTj;&  
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背景： dV?5Q_}  
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。 @>x pYV  
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。 NDO\B,7  
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步骤 >\<*4J$PZ  
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1、 在http://www.rpcphotonics.com/bsdf-data-optical-diffusers/下载并解压BSDF数据到某一文件夹下，选择“Raw data”文件。 qW_u  
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2、 将     http://fred-kb.photonengr.com/wp-content/uploads/sites/2/2015/06/constructRpcScatterFile.frs脚本文件放在步骤1中的文件下。（脚本代码放在了本文的最后） fU2qrcVu  
3、 打开FRED并运行脚本文件，会输出如下“<SAMPLE>_FRED.txt”格式，<SAMPLE>即为RPC Photonics散射片数据集 hIJ)MZU|  
例如下所示： 6 fz
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Sample name:  EDF-C1-56 utlpY1#q/  
Merging data from file EDF-C1-56 0-0.txt R)Mt(gFZT_  
Finished merging RPC data for sample EDF-C1-56 V2|3i}V"  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt M!M!Ni  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 ?RFg$Z'^  
a. 创建一个新的散射库 qJR!$?  
b. 散射模型命名 kJs^ z  
c. 改变散射模型为“Tabulated BSDF”. l]2
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d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） m+$ @'TbP  
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&"|}Pi/  
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， *oI*-C  
g. 点击OK ]7AX%EG3  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 17g^ALs  
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脚本代码： o**yZ2  
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'#Language "WWB-COM" C.!_]Pxs  
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Option Explicit
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Sub Main ^b?2N/m@  
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    'Cleanup )wzV $(~  
    ClearOutputWindow() &217l2X /  
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    Print "Merging RPC Photonics BSDF Data Files" 9
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    SetTextColor(255,0,0) 3mt%!}S  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." 8_\W/I!7b  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." |E/L.gdP7  
    SetTextColor(0,0,0) zjX7C~h^Q  
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    'Current directory of this script (should be the same as the text files being merged) \Mx JH[  
    Dim cDir As String zxZtz  
    cDir = MacroDir$ & "\" r;cV&T/?  
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    'Array which will be populated with the list of files to be merged |@VF.)_  
    Dim fList() As String, curFile As String @y~P&HUN  
    GetFileList( cDir, fList ) \Xg?Ug*9w  
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    Print "" XbvDi+R2A  
    Print "Files found for merging:" ^Ip3A  
    For Each curFile In fList fJ80tt?r  
        Print Chr(9) & curFile JSMPyj  
    Next yDd[e]zS`  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. l`n5~Fs  
    Dim nameArray() As String, sampName As String udqge?Tz  
    nameArray = Split(fList(0)," 0-0.txt") j^u[F"  
    sampName  = nameArray(0) ?KN:r E  
    Print "" $G?(OWI}l`  
    Print "Sample name: " & Chr(9) & sampName z)L}ECZh9  
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    'Open an output file and write the FRED header data M?6;|-HH  
    Dim outFile As String sB*o)8  
    outFile = cDir & sampName & "_FRED.txt" I^0t2[M  
    Open outFile For Output As #1 whkJpK(  
    Print #1, "type bsdf_data" Z(!pYhLq  
    Print #1, "format angles=deg bsdf=value scale=1" ] VG?+  
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    'Loop the file list, skip the two header lines and write the remaining data to file u35q,u=I  
    Dim lineArray() As String, curLine As Long *=nO  
    For Each curFile In fList NtZ6$o<Y  
        Print "Merging data from file " & curFile Kr3];(w{  
        ReadFile( cDir & curFile, lineArray ) fNhT;Bux  
        For curLine = 2 To UBound(lineArray) *%- ?54B  
            Print #1, lineArray(curLine) |_pl;&;:  
        Next j=3-Qk`"/|  
    Next O2#S: ~h  
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    'Close the output file ^e9aD9  
    Close #1 W8/(;K`/  
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    Print "Finished merging RPC data for sample " & sampName 1Ii| {vR  
    Print "FRED formatted data file: " & Chr(9) & outFile ?V+wjw  
End Sub 1mUTtYU  
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'Utility function to read the contents of a file into an array of strings. I6w/0,azC  
Function ReadFile(ByVal fileName As String, _ ,olwwv_8G  
                  ByRef lineArray() As String) As Long d^aNR Lv  
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    ReadFile = -1 @ M[Q$:  
    Dim oFSO As Object r@$B'CsLj  
    Set oFSO = CreateObject("Scripting.FileSystemObject") ,C!n}+27  
    Erase lineArray |3@=CE7G  
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    Dim fid As Long {})y^L  
    If oFSO.fileexists( fileName ) Then X%J%A-k]  
        fid = FreeFile() \!PV*%P  
        Open fileName For Input As fid G2@KI-  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) v72,h  
        Close fid ,8`O7V{W  
    End If |BJqy/  
    Set oFSO = Nothing SKxe3  
    Return UBound( lineArray ) h6FgS9H  
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End Function wb+<a  
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Sub GetFileList( ByVal in_dir As String, _ .;Z.F7{q  
                 ByRef in_flist() As String ) $[QcEk  
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    'Redimension the file list array Ut;'Gk  
    Erase in_flist ohTd'+Lm  
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    'Tracks how many files are found 0.(Ml5&e  
    Dim fCount As Long 4 m$sJ  
    fCount = 0 "i''Ui\H  

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    'Recurse directory and search for text files -7
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    Dim f As String '_E c_F  
    f = Dir$(in_dir & "*.txt") 0%;MVMH  
    While f <> ""
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        ReDim Preserve in_flist(fCount) f-]><z  
        in_flist(fCount) = f a(!3Afi  
        fCount += 1 LH.%\TMN$  
        f = Dir$() pg5&=  
    Wend eEie?#Z/6  
    ReDim Preserve in_flist(fCount-1) q-uLA&4  
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End Sub b\M b*o