[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： ?AY596  
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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。 zE.4e&m%Z?  
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背景： `Pl=%DR  
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。 -<&"geJA  
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。 .(;k]U
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步骤 $Ry NM2YI  
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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。 uK(+WA  
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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） ,O a)  
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 g;]2'Rj  
例如下所示： 5bmtUIj  
Sample name:  EDF-C1-56 drtQEc>qT  
Merging data from file EDF-C1-56 0-0.txt ?WUE+(oH>  
Finished merging RPC data for sample EDF-C1-56 .M:,pw"S]  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt oL}FD !}  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 D zDt:.JZ  
a. 创建一个新的散射库 3L>V-RPiM  
b. 散射模型命名 N@)4H2_u \  
c. 改变散射模型为“Tabulated BSDF”. @gX@
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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 ） MiOSSl};  
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。  mH?^3T  
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， >y]YF3?  
g. 点击OK sFS_CyN!7  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 sMO3eNLn  
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脚本代码： $$qhX]^~  
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'#Language "WWB-COM" yx/:<^"-$  
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Option Explicit O4$: xjs  
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Sub Main SxT:k,ji  
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    'Cleanup #lVVSrF,-  
    ClearOutputWindow() 5gJQr%pS  
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    Print "Merging RPC Photonics BSDF Data Files" = )(;  
    SetTextColor(255,0,0) 1uy+'2[Z-D  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." Jge;/f!i  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." t5e(9Yhj  
    SetTextColor(0,0,0) "sHD8TUX  
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    'Current directory of this script (should be the same as the text files being merged) }:hdAZ+z  
    Dim cDir As String l_}c[bAUu  
    cDir = MacroDir$ & "\"  d;CD~s  
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    'Array which will be populated with the list of files to be merged 7x1jpQ-  
    Dim fList() As String, curFile As String o^AK@\e:^Z  
    GetFileList( cDir, fList ) C(gH}N4  
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    Print "" ^rxXAc[  
    Print "Files found for merging:" 7qh_URt@  
    For Each curFile In fList !A<?nz Uv  
        Print Chr(9) & curFile %OzxR9  
    Next b9\=NdyCY  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. Ig9$ PP+3  
    Dim nameArray() As String, sampName As String f:
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    nameArray = Split(fList(0)," 0-0.txt") r\em-%:  
    sampName  = nameArray(0) g4~{#P^i  
    Print "" 4ci @$nL1  
    Print "Sample name: " & Chr(9) & sampName `Y'}\>.#  
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    'Open an output file and write the FRED header data r?[Zf2&  
    Dim outFile As String Q4Cw{2r  
    outFile = cDir & sampName & "_FRED.txt" (s\Nm_j  
    Open outFile For Output As #1 $)PNf'5Zg  
    Print #1, "type bsdf_data" /)v X|qtIY  
    Print #1, "format angles=deg bsdf=value scale=1" L]9*^al  
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    'Loop the file list, skip the two header lines and write the remaining data to file zR]l2zL3  
    Dim lineArray() As String, curLine As Long  5)mn  
    For Each curFile In fList A2htD!3  
        Print "Merging data from file " & curFile C/lpSe  
        ReadFile( cDir & curFile, lineArray ) C~kw{g+|  
        For curLine = 2 To UBound(lineArray) UXe@c@3  
            Print #1, lineArray(curLine) |nv8&L8  
        Next ^F
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    Next WG1x:,-  
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    'Close the output file k`xPf\^tf  
    Close #1 ql^n=+U  
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    Print "Finished merging RPC data for sample " & sampName 8*6U4R  
    Print "FRED formatted data file: " & Chr(9) & outFile [N.4i" Cd  
End Sub C+jlIT+  
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'Utility function to read the contents of a file into an array of strings. sF f@>  
Function ReadFile(ByVal fileName As String, _ AvH^9zEE(  
                  ByRef lineArray() As String) As Long :[,-wZiT~6  
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    ReadFile = -1 }~y i6!w'  
    Dim oFSO As Object t#=W'HyW8  
    Set oFSO = CreateObject("Scripting.FileSystemObject") ?7*.S Lt  
    Erase lineArray ?s6v>#H%  
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    Dim fid As Long jH({Qc,97  
    If oFSO.fileexists( fileName ) Then xG/B$DLn  
        fid = FreeFile() `1{Y9JdQ  
        Open fileName For Input As fid 9$$dSN\&  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) "m4._4U  
        Close fid )[+82~F  
    End If GRM6H|.
  
    Set oFSO = Nothing ^CO{86V  
    Return UBound( lineArray ) uGOED-@  
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End Function hK+6S3-Ez  
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Sub GetFileList( ByVal in_dir As String, _ 4a}[&zm(5  
                 ByRef in_flist() As String ) @QteC@k  
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    'Redimension the file list array @GUlw[vi  
    Erase in_flist h?[|1.lJx(  
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    'Tracks how many files are found ;NU-\<Q{  
    Dim fCount As Long <aztbq?  
    fCount = 0 b:Z&;A|"{  
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    'Recurse directory and search for text files \?SvO  
    Dim f As String J3`0i@  
    f = Dir$(in_dir & "*.txt") ])}a^]0q  
    While f <> "" jr,N+K(@T  
        ReDim Preserve in_flist(fCount) nr2 Q[9~  
        in_flist(fCount) = f $=iw<B r  
        fCount += 1 Q$uv \h;  
        f = Dir$() y];-D>jk  
    Wend {`QA.he.  
    ReDim Preserve in_flist(fCount-1) Aa=:AkrH  
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End Sub Z:dp/M}