[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： 9,4Lb]  
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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。 FM)Es&p&  
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背景： &3Q!'pJJ  
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。 'ow`ej  
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。 8%dE$smH  
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步骤 {p{TG5rwX  
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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。 lm?1 K:+[  
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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） uz(3ml^S  
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 rHir> p  
例如下所示： ]ZQ3|ZJ?<  
Sample name:  EDF-C1-56 b>B.3E\Pc  
Merging data from file EDF-C1-56 0-0.txt ^=H. .pr  
Finished merging RPC data for sample EDF-C1-56 ~JJuM  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt |6%B2I&c  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 kIb)I(n  
a. 创建一个新的散射库 )}-,4Iu%  
b. 散射模型命名 h@5mVTb}i  
c. 改变散射模型为“Tabulated BSDF”. t(O{IUYM  
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 ） *nv%~t   
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。 .#M'  
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， s)=fs#%  
g. 点击OK I.f)rMl+h  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 k* ayzg3F>  
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脚本代码： FCC9Ht8U?  
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'#Language "WWB-COM" Z'P>sV  
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Option Explicit ZeUA e  
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Sub Main ,cbCt  
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    'Cleanup %_rdO(   
    ClearOutputWindow() h&$7^P  
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    Print "Merging RPC Photonics BSDF Data Files" ^ |k7g  
    SetTextColor(255,0,0) X=i^[?C  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." )T-C/
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    Print "Note: Do not run this script multiple times without deleting the output file between executions." 2yu\fu  
    SetTextColor(0,0,0) :x36^{7  
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    'Current directory of this script (should be the same as the text files being merged) uM!$`JN  
    Dim cDir As String i8F^ N=  
    cDir = MacroDir$ & "\" VJK?"mX  
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    'Array which will be populated with the list of files to be merged P}] xz Vy  
    Dim fList() As String, curFile As String J}Q4.1WG$  
    GetFileList( cDir, fList ) I7b_dJD;*  
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    Print "" HLL[r0P`F  
    Print "Files found for merging:" pvCf4pf~  
    For Each curFile In fList Md~% e'  
        Print Chr(9) & curFile b51{sL  
    Next :[;]6;
 
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. g"Eg=CU  
    Dim nameArray() As String, sampName As String v8 Q/DJ~  
    nameArray = Split(fList(0)," 0-0.txt") k<1BE^[V  
    sampName  = nameArray(0) 0q|.]:][Eo  
    Print "" _0~WT  
    Print "Sample name: " & Chr(9) & sampName X2X.&^  
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    'Open an output file and write the FRED header data {s=n "*Qp)  
    Dim outFile As String o5!"dxR  
    outFile = cDir & sampName & "_FRED.txt" 5Ocd2T'  
    Open outFile For Output As #1 v9<7=D&x  
    Print #1, "type bsdf_data" Y<~Nx~w{  
    Print #1, "format angles=deg bsdf=value scale=1" j"F
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    'Loop the file list, skip the two header lines and write the remaining data to file 8Iz-YG~%3  
    Dim lineArray() As String, curLine As Long t<_Jx<{2  
    For Each curFile In fList .~)[>  
        Print "Merging data from file " & curFile K"p$ga{  
        ReadFile( cDir & curFile, lineArray ) f.V
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        For curLine = 2 To UBound(lineArray) >(v%"04|e  
            Print #1, lineArray(curLine) ']nB_x7  
        Next G#V}9l
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    Next 4'&j<Ah[#  
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    'Close the output file x"hZOgFZ  
    Close #1 I6bekOvP  
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    Print "Finished merging RPC data for sample " & sampName 
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    Print "FRED formatted data file: " & Chr(9) & outFile deD%E-Ja  
End Sub $ O1w6\}_  
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'Utility function to read the contents of a file into an array of strings. q3+G  
Function ReadFile(ByVal fileName As String, _ nZ;h&N-_-  
                  ByRef lineArray() As String) As Long Yzr RnVr  
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    ReadFile = -1 z^+`S:  
    Dim oFSO As Object /u9Md3q*'  
    Set oFSO = CreateObject("Scripting.FileSystemObject") x/nlIoT  
    Erase lineArray MQL1/>j;  
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    Dim fid As Long zzf;3S?  
    If oFSO.fileexists( fileName ) Then %bM^/7  
        fid = FreeFile() 3t  
        Open fileName For Input As fid ("2ukHc  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) r 5!ie!5gE  
        Close fid yo)a_rY  
    End If ~vD7BO`  
    Set oFSO = Nothing 44H#8kV  
    Return UBound( lineArray ) Qr`WPTQr"  
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End Function [emUyF  
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Sub GetFileList( ByVal in_dir As String, _ &^ECQ  
                 ByRef in_flist() As String ) g~ tG  
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    'Redimension the file list array 5):2;hk  
    Erase in_flist % K$om|]p  
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    'Tracks how many files are found sOc<'):TK  
    Dim fCount As Long e:9CD-  
    fCount = 0 y %dUry%>  
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    'Recurse directory and search for text files P;%4Imq3  
    Dim f As String ?Ji.bnfK  
    f = Dir$(in_dir & "*.txt") nSH A,c  
    While f <> "" GarPnb  
        ReDim Preserve in_flist(fCount) R|PFGhi6"A  
        in_flist(fCount) = f yZf+*j/a7  
        fCount += 1 xrbDqA.b  
        f = Dir$() xPa>-N=*  
    Wend [m*=Q  
    ReDim Preserve in_flist(fCount-1) 8'=8!V  
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End Sub ([loWr}QR