[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： ,'&H`h54  
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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。 B<oBo&uA  
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背景： *^[j6  
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。 4rrR;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。 G-e
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步骤 e"&QQ-q  
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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。 1
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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） B
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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 {fa3"k_ke  
例如下所示： ]Gf`nJDV  
Sample name:  EDF-C1-56 cUC!'+L  
Merging data from file EDF-C1-56 0-0.txt .X34[AXd  
Finished merging RPC data for sample EDF-C1-56 MIdViS.g  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt P(cy@P
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4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 #eIFRNRb)  
a. 创建一个新的散射库 -Pc6W9$  
b. 散射模型命名 Cf>(,rt};  
c. 改变散射模型为“Tabulated BSDF”. -;*lcY*  
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 ） Mh~E]8b  
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。 7> 8L%(7  
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， KZ@'NnQ  
g. 点击OK 8\Bb7*  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 d r$E:kr  
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脚本代码： :B:6ezDF6  
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'#Language "WWB-COM" lRR A2Kql  
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Option Explicit nXw98;  
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Sub Main G_<4% HM  
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    'Cleanup Q2[;H!"  
    ClearOutputWindow() vUhgM'  
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    Print "Merging RPC Photonics BSDF Data Files" p0hE`!  
    SetTextColor(255,0,0) 8QMib3p  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." wKKQAM6P1  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." .FG%QFF~  
    SetTextColor(0,0,0)
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    'Current directory of this script (should be the same as the text files being merged) rFaG-R  
    Dim cDir As String 6ZfL-E{  
    cDir = MacroDir$ & "\" HI7w@V
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    'Array which will be populated with the list of files to be merged r1:CHIwK  
    Dim fList() As String, curFile As String wf`A&P5tF  
    GetFileList( cDir, fList ) ,B'fOJ.2  
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    Print "" mM:%-I\$   
    Print "Files found for merging:" -iL:D<!Cb_  
    For Each curFile In fList me@)kQ8M  
        Print Chr(9) & curFile *wx95?H0Z  
    Next S%aup(wu6  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. 4w)>}  
    Dim nameArray() As String, sampName As String ;cB3D3fR.  
    nameArray = Split(fList(0)," 0-0.txt") sNM ]bei  
    sampName  = nameArray(0) E^A S65%bL  
    Print "" +lb&_eD  
    Print "Sample name: " & Chr(9) & sampName B
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    'Open an output file and write the FRED header data a~ dgf:e`  
    Dim outFile As String L9-Jwy2(>  
    outFile = cDir & sampName & "_FRED.txt" Ft?eqDS1  
    Open outFile For Output As #1 )Xa_ry7  
    Print #1, "type bsdf_data" f;AI4:#I  
    Print #1, "format angles=deg bsdf=value scale=1" ]|tR8`DGZ%  
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    'Loop the file list, skip the two header lines and write the remaining data to file k||dX(gl  
    Dim lineArray() As String, curLine As Long S`$%C=a.  
    For Each curFile In fList |1zfXG,R  
        Print "Merging data from file " & curFile Tdm|=xI  
        ReadFile( cDir & curFile, lineArray ) (cyvE}g  
        For curLine = 2 To UBound(lineArray) zc$}4o  
            Print #1, lineArray(curLine) L^*f$Balz  
        Next U8J9 #+:  
    Next 1\~I "$}  
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    'Close the output file &>]U c%JK  
    Close #1 7F2 RH 8)  
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    Print "Finished merging RPC data for sample " & sampName T*%rhnTv0  
    Print "FRED formatted data file: " & Chr(9) & outFile <bb!BS&w  
End Sub TgaxZW  
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'Utility function to read the contents of a file into an array of strings. bX$1PYX  
Function ReadFile(ByVal fileName As String, _ ?dbSm3  
                  ByRef lineArray() As String) As Long qS9<_if2  
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    ReadFile = -1 J]#rh5um  
    Dim oFSO As Object W
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    Set oFSO = CreateObject("Scripting.FileSystemObject") [NAfy~X*  
    Erase lineArray I;-Y2*  
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    Dim fid As Long (xHu@l!]  
    If oFSO.fileexists( fileName ) Then @&Z^WN,x  
        fid = FreeFile() .{\eco  
        Open fileName For Input As fid ^ghYi|kQq  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) }dpTR
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        Close fid wU>Fz*  
    End If
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    Set oFSO = Nothing R?{xs  
    Return UBound( lineArray ) !+A%`m  
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End Function \pfa\,rW  
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Sub GetFileList( ByVal in_dir As String, _ 9:Oz-b  
                 ByRef in_flist() As String ) VnVBA-#r|  
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    'Redimension the file list array 3qn_9f]  
    Erase in_flist ,dR.Sacv  
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    'Tracks how many files are found /'aqQ K<  
    Dim fCount As Long
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    fCount = 0 rR :ZTfJs"  
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    'Recurse directory and search for text files `YC7+`q  
    Dim f As String eA86~M?<o  
    f = Dir$(in_dir & "*.txt") )~)l^0X  
    While f <> "" Ht4O5yl"  
        ReDim Preserve in_flist(fCount) :CW^$Zvq  
        in_flist(fCount) = f VC/-5'_6  
        fCount += 1 Te L&6F$  
        f = Dir$() ;b
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    Wend w~)tEN>  
    ReDim Preserve in_flist(fCount-1) Bh'fkW3  
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End Sub Q5T3