[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： @E 8
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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。 acrR  
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背景： 6Hbu7r*tm  
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。 r<$o [,W  
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。 @)\4 $#+-  
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步骤 (xfh 9=.  
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1、 在http://www.rpcphotonics.com/bsdf-data-optical-diffusers/下载并解压BSDF数据到某一文件夹下，选择“Raw data”文件。 [ *Dj7zt:  
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2、 将     http://fred-kb.photonengr.com/wp-content/uploads/sites/2/2015/06/constructRpcScatterFile.frs脚本文件放在步骤1中的文件下。（脚本代码放在了本文的最后） lA%FS]vh  
3、 打开FRED并运行脚本文件，会输出如下“<SAMPLE>_FRED.txt”格式，<SAMPLE>即为RPC Photonics散射片数据集 k#bG&BF  
例如下所示： <UF0Xc&X'  
Sample name:  EDF-C1-56 %s497'  
Merging data from file EDF-C1-56 0-0.txt QChncIqc  
Finished merging RPC data for sample EDF-C1-56 +OqEe[Wk#  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt jST4O"DjM  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 42~.N=2  
a. 创建一个新的散射库 Y)
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b. 散射模型命名 [UXN= 76N  
c. 改变散射模型为“Tabulated BSDF”. "u]&~$  
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 ） r;xy/*%Mtj  
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。 99.F'Gz  
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， c7~R0nP  
g. 点击OK 8\"Gs z  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 }zks@7kf  
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脚本代码： gyMHC{l/B  
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'#Language "WWB-COM" ~|9VVeE  
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Option Explicit O!%T<2
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Sub Main gyD;kn\CP  
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    'Cleanup D HT^.UM28  
    ClearOutputWindow() ,,BP}f+l$  
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    Print "Merging RPC Photonics BSDF Data Files" Bcarx<P-p  
    SetTextColor(255,0,0) mE`qA*=?  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." b~}$Ch3ymW  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." /W)A[jR  
    SetTextColor(0,0,0) hrtz>qN  
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    'Current directory of this script (should be the same as the text files being merged) GyWa=KW.u  
    Dim cDir As String (bQ3:%nD  
    cDir = MacroDir$ & "\" C<AW)|r_  
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    'Array which will be populated with the list of files to be merged i
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    Dim fList() As String, curFile As String C=V2Y_j  
    GetFileList( cDir, fList ) F'b%D  
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    Print "" ] re=8s6  
    Print "Files found for merging:" $GFR7YC 7  
    For Each curFile In fList A$3Rb
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        Print Chr(9) & curFile m9oOH5@K~  
    Next {?eUAB<  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. N=BG0t$  
    Dim nameArray() As String, sampName As String *$g!/,  
    nameArray = Split(fList(0)," 0-0.txt") GeTk/tU  
    sampName  = nameArray(0) *u1q7JFQk  
    Print "" VFL^-tXnA^  
    Print "Sample name: " & Chr(9) & sampName
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    'Open an output file and write the FRED header data W~'xJ  
    Dim outFile As String k?14'X*7yu  
    outFile = cDir & sampName & "_FRED.txt" RyJy%|\-S  
    Open outFile For Output As #1 3$nK   
    Print #1, "type bsdf_data" 9pqsr~  
    Print #1, "format angles=deg bsdf=value scale=1" din,yHu~  
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    'Loop the file list, skip the two header lines and write the remaining data to file  f\<r1  
    Dim lineArray() As String, curLine As Long ixu*@{
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    For Each curFile In fList !k)6r6  
        Print "Merging data from file " & curFile ^ ~Eh+  
        ReadFile( cDir & curFile, lineArray ) p H y  
        For curLine = 2 To UBound(lineArray) yV!4Im.>  
            Print #1, lineArray(curLine) js<d"m*  
        Next {*7MT}{(  
    Next |6*Bu1  
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    'Close the output file NS[eQ_rT  
    Close #1 \vAjg  
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    Print "Finished merging RPC data for sample " & sampName @.e X8~3=  
    Print "FRED formatted data file: " & Chr(9) & outFile < '5~p$  
End Sub <:v+<)K  
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'Utility function to read the contents of a file into an array of strings. *p}mn
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Function ReadFile(ByVal fileName As String, _ ^3$l!>me  
                  ByRef lineArray() As String) As Long lGd'_~'=  
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    ReadFile = -1  + Q-b}  
    Dim oFSO As Object fjRVYOG#  
    Set oFSO = CreateObject("Scripting.FileSystemObject") !g
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    Erase lineArray UX)GA[WI  
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    Dim fid As Long ~rb0G*R>  
    If oFSO.fileexists( fileName ) Then 4X
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        fid = FreeFile() S<
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        Open fileName For Input As fid iHD!v7d7  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) ]@&X*~c^Z  
        Close fid F0:]@0>r  
    End If %Rk|B`ST  
    Set oFSO = Nothing =l`)b  
    Return UBound( lineArray ) #fuUAbU0X  
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End Function g&$=Y7G  
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Sub GetFileList( ByVal in_dir As String, _ &6x(
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                 ByRef in_flist() As String ) yfG;OnkZ  
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    'Redimension the file list array 0?7yM:!l  
    Erase in_flist C >*z^6Gz  
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    'Tracks how many files are found C]ss'  
    Dim fCount As Long 5|H;%T3_  
    fCount = 0 \*$^}8  
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    'Recurse directory and search for text files Qte5E}V`  
    Dim f As String ]rG=\>U3~  
    f = Dir$(in_dir & "*.txt") ?qjdmB|w  
    While f <> "" CD`a-]6qA  
        ReDim Preserve in_flist(fCount) t ed:]  
        in_flist(fCount) = f kF|$oBQ  
        fCount += 1 z9o]
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        f = Dir$() !<w6j-S  
    Wend K"!rj.Da  
    ReDim Preserve in_flist(fCount-1) F
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End Sub V;SfW2`)