[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： U;dt-3?=.h  
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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。 l*MUDT@M8\  
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背景： KK3xz*W0  
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。 5
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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>j`  
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步骤 Zd/~ *ZA  
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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)2hl~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） CKw)J}z  
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 
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例如下所示： 5kZ yiC*  
Sample name:  EDF-C1-56 CPE F,,\  
Merging data from file EDF-C1-56 0-0.txt a8P6-)W  
Finished merging RPC data for sample EDF-C1-56 QHz76i!=>  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt yj9gN}+  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 W/X;|m`  
a. 创建一个新的散射库 Z"KuS  
b. 散射模型命名 5Cka."bQ  
c. 改变散射模型为“Tabulated BSDF”. /s_$CSiB  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） ~?+m=\  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 +-137!x\q  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， (pNng"/  
g. 点击OK =qQQ^`^F'~  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 F=c_PQO  
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脚本代码： 'J2P3t  
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'#Language "WWB-COM" B\w`)c  
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Option Explicit y_r6T XnGL  
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Sub Main +'4dP#  
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    'Cleanup tC~itU=V  
    ClearOutputWindow() {<BK@U  
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    Print "Merging RPC Photonics BSDF Data Files" 2p[3Ap  
    SetTextColor(255,0,0) |mA*[?ye@  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." I2Rp=L:z5  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." l0_O<  
    SetTextColor(0,0,0) WR1,J0UU6  
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    'Current directory of this script (should be the same as the text files being merged) .r"?w  
    Dim cDir As String KrzM]x  
    cDir = MacroDir$ & "\" ~'mhC46d  
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    'Array which will be populated with the list of files to be merged U\6DEnII?!  
    Dim fList() As String, curFile As String [AwE  
    GetFileList( cDir, fList ) >f/g:[  
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    Print "" DR=1';63  
    Print "Files found for merging:" C"WZsF^3  
    For Each curFile In fList ^Y |s^N  
        Print Chr(9) & curFile 5E=Odep`  
    Next {`55nwd  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. WRM}gWv*  
    Dim nameArray() As String, sampName As String N*W.V,6yH  
    nameArray = Split(fList(0)," 0-0.txt") Dh<e9s:  
    sampName  = nameArray(0) qo|iw+0Y  
    Print "" .ji%%f  
    Print "Sample name: " & Chr(9) & sampName ( PlNaasV  
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    'Open an output file and write the FRED header data voEc'JET  
    Dim outFile As String nX'.'3  
    outFile = cDir & sampName & "_FRED.txt" .}s a2-  
    Open outFile For Output As #1 _aYQ(FO  
    Print #1, "type bsdf_data" y 6<tV.  
    Print #1, "format angles=deg bsdf=value scale=1" ;<H2N0qJ(  
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    'Loop the file list, skip the two header lines and write the remaining data to file (""&$BJQ|  
    Dim lineArray() As String, curLine As Long eH6cBX#P.  
    For Each curFile In fList M`'2 a  
        Print "Merging data from file " & curFile +>j_[O5Y  
        ReadFile( cDir & curFile, lineArray ) vD t?N9  
        For curLine = 2 To UBound(lineArray) gw:BKR'o  
            Print #1, lineArray(curLine) P])O\
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        Next Sq>UMfl&  
    Next Pipif.  
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    'Close the output file YR2/`9s\QJ  
    Close #1 F_`Gs8-VH  
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    Print "Finished merging RPC data for sample " & sampName M*%Z5,Tc  
    Print "FRED formatted data file: " & Chr(9) & outFile Lq.k?!D3uh  
End Sub PX]v"xf  
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'Utility function to read the contents of a file into an array of strings.
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Function ReadFile(ByVal fileName As String, _
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                  ByRef lineArray() As String) As Long '"Gi&:*nQ<  
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    ReadFile = -1 wvD|c%   
    Dim oFSO As Object zuw6YY8kQ  
    Set oFSO = CreateObject("Scripting.FileSystemObject") I]58;|J  
    Erase lineArray FU zY&@Y  
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    Dim fid As Long 7Jbr
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    If oFSO.fileexists( fileName ) Then "\ m
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        fid = FreeFile() ryPzq}#  
        Open fileName For Input As fid ~Q5HM  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) QMP:}  
        Close fid %-D2I  
    End If R4?/7  
    Set oFSO = Nothing 7-)KTBFL  
    Return UBound( lineArray ) MeC@+@C  
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End Function TD<.:ul]  
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Sub GetFileList( ByVal in_dir As String, _ %y'#@%kO:S  
                 ByRef in_flist() As String ) (Q&Z/Fe  
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    'Redimension the file list array zKo,B/Ke4  
    Erase in_flist P:G^@B3^  
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    'Tracks how many files are found K7|BXGL8r8  
    Dim fCount As Long U<$|ET'  
    fCount = 0 @C#lA2(I4  
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    'Recurse directory and search for text files $|AxQQ%f  
    Dim f As String h1xYQF_`Z  
    f = Dir$(in_dir & "*.txt") 0[^f9NZ>-  
    While f <> "" :0/I2:  
        ReDim Preserve in_flist(fCount) !U@[lBW  
        in_flist(fCount) = f sNWj+T  
        fCount += 1 WE\V<MGS/  
        f = Dir$() IIzdCa{l  
    Wend rRxqV?>n!  
    ReDim Preserve in_flist(fCount-1) ,xGkE7=5  
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End Sub :7'anj