[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： RW| LL@r  
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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。 qJV2x.!  
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背景： 3j<:
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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。 }nh!dVA8lh  
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。  uP|Py.+  
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步骤 'dJ#NT25  
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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。 9vIqGz-o  
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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） Dxp8^VL  
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 f3_-{<FZ  
例如下所示： XS:W{tL!  
Sample name:  EDF-C1-56 n1 k2<BU4b  
Merging data from file EDF-C1-56 0-0.txt ":=\ci]e%  
Finished merging RPC data for sample EDF-C1-56 Y:o\qr!Y  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt U|tUX)9O  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 B$ty`/{w,B  
a. 创建一个新的散射库 +=.>9  
b. 散射模型命名 UqVcN$^b  
c. 改变散射模型为“Tabulated BSDF”. w=e_@^Fkx  
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 ） rq#8
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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。 $y%X#:eLJ  
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， yg}zK>j^vC  
g. 点击OK BhAWIH8@C  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 n*(9:y=l1  
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脚本代码： ~H<oqk:O-  
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'#Language "WWB-COM" d,%e?8x5  
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Option Explicit R'Gka1v  
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Sub Main `.oWmBey\  
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    'Cleanup 'YQVf]4P  
    ClearOutputWindow() PhUG}94  
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    Print "Merging RPC Photonics BSDF Data Files" 'gBGZ?^N!U  
    SetTextColor(255,0,0) g=ehAg
 
    Print "Note: Script should be located in the same folder as the BSDF TXT files." tW^oa  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." @=i-*
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    SetTextColor(0,0,0) I,7~D!4G  
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    'Current directory of this script (should be the same as the text files being merged) \,n|V3#G  
    Dim cDir As String \@\r`=WgB  
    cDir = MacroDir$ & "\" k4n4BL  
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    'Array which will be populated with the list of files to be merged y nue;*rM  
    Dim fList() As String, curFile As String !O*'mX  
    GetFileList( cDir, fList ) ^l,(~03_  
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    Print "" \C{Dui)F  
    Print "Files found for merging:" k<&zVV'  
    For Each curFile In fList wOMrUWB0  
        Print Chr(9) & curFile `s )- lI  
    Next Etj0k} A  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. :D|5E
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    Dim nameArray() As String, sampName As String Ru&>8Ln0  
    nameArray = Split(fList(0)," 0-0.txt") )a7nr<)aU  
    sampName  = nameArray(0) s'7PHP)LOJ  
    Print "" c*m7'\  
    Print "Sample name: " & Chr(9) & sampName *\-$.w)k  
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    'Open an output file and write the FRED header data Hto RN^9  
    Dim outFile As String iH`Q4  
    outFile = cDir & sampName & "_FRED.txt" WX-J4ieL  
    Open outFile For Output As #1 B0M(&)!%  
    Print #1, "type bsdf_data" S|jE1v"L  
    Print #1, "format angles=deg bsdf=value scale=1" yjF;%A/0  
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    'Loop the file list, skip the two header lines and write the remaining data to file $q|-9B  
    Dim lineArray() As String, curLine As Long 2iWSk6%R  
    For Each curFile In fList h&|S*  
        Print "Merging data from file " & curFile Yy 8?X9r.  
        ReadFile( cDir & curFile, lineArray ) x]Pp|rHj  
        For curLine = 2 To UBound(lineArray) p{vGc-zP.  
            Print #1, lineArray(curLine) ;_K3/:  
        Next hl/) 1sOIR  
    Next sk%Xf,  
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    'Close the output file %&5PZmnW  
    Close #1 De-hHY{>  
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    Print "Finished merging RPC data for sample " & sampName 6"L,#aKm^  
    Print "FRED formatted data file: " & Chr(9) & outFile d}w}VL8l  
End Sub R<<U(.E  
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'Utility function to read the contents of a file into an array of strings. n1Wo<$#  
Function ReadFile(ByVal fileName As String, _ mB5Sm|{  
                  ByRef lineArray() As String) As Long w7%.EA{N  
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    ReadFile = -1 rj ] ~g  
    Dim oFSO As Object v;sWI"Fv!  
    Set oFSO = CreateObject("Scripting.FileSystemObject") _2a)b(<tF  
    Erase lineArray )z_5I (?&  
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    Dim fid As Long |V&E q>G  
    If oFSO.fileexists( fileName ) Then .WVIdVO7  
        fid = FreeFile() | 9 <+!t\  
        Open fileName For Input As fid 2PC:F9dh\  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) xE5VXYU  
        Close fid #z5$_z?_  
    End If s/0bXM$^  
    Set oFSO = Nothing 6pdek3pOCt  
    Return UBound( lineArray ) RI3GAd  
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End Function tc|PN+v;  
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Sub GetFileList( ByVal in_dir As String, _ E*vh<C  
                 ByRef in_flist() As String ) b:Tv Ta  
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    'Redimension the file list array 5D <  
    Erase in_flist HoO1_{q"  
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    'Tracks how many files are found YM,UM>  
    Dim fCount As Long lyzM?lK-  
    fCount = 0 +&4@HHU{G  
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    'Recurse directory and search for text files Rr0]~2R  
    Dim f As String Od+nBJ   
    f = Dir$(in_dir & "*.txt") pHzl/b8  
    While f <> "" wCEcMVT  
        ReDim Preserve in_flist(fCount) T`2a)  
        in_flist(fCount) = f *pYawT  
        fCount += 1 d-jZ5nl(  
        f = Dir$() =>-W!Of  
    Wend e
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    ReDim Preserve in_flist(fCount-1) jG%J.u^k  
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End Sub 6t{G{ ]