[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： /2VJX@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。 ,MIV=*  
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背景： ,9 a  
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。 |(^PS8wG  
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。 I1&aM}y{G  
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步骤 .6 ?U@2  
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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。 UJ6v(:z<  
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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） vs{s_T7Mz]  
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 kB%JNMF{A  
例如下所示： FHI ;)wn=  
Sample name:  EDF-C1-56 a7%]Y}$  
Merging data from file EDF-C1-56 0-0.txt iO; 7t@]-  
Finished merging RPC data for sample EDF-C1-56 Pj%|\kbNs  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt uWE^hz"  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 Dv`c<+q(#  
a. 创建一个新的散射库 x]ot 2  
b. 散射模型命名 "kqPmeI  
c. 改变散射模型为“Tabulated BSDF”. RViuJ;  
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 ） @7n"yp*"  
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。 !jR=pIfq  
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， L_i
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g. 点击OK NQ2E  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 ;,e2egC'  
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脚本代码： +=8VTCn?  
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'#Language "WWB-COM" jrh43 \$*  
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Option Explicit VY\&8n}e(  
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Sub Main }RqK84K  
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    'Cleanup (Ep\Z 6*  
    ClearOutputWindow() L*JjG
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    Print "Merging RPC Photonics BSDF Data Files" @F*%9LPv  
    SetTextColor(255,0,0) f& '  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." VP]%Hni]  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." 12LL48bi  
    SetTextColor(0,0,0) uGlUc<B\*  
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    'Current directory of this script (should be the same as the text files being merged) {/:x5l8  
    Dim cDir As String M=r)I~  
    cDir = MacroDir$ & "\" ^y%T~dLkp'  
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    'Array which will be populated with the list of files to be merged gB'6`'  
    Dim fList() As String, curFile As String [ibu/W$  
    GetFileList( cDir, fList ) D,FkB"ZZE  
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    Print "" C3YT1tK  
    Print "Files found for merging:" o`*,|Nsq  
    For Each curFile In fList C~iL3Cb  
        Print Chr(9) & curFile CzEd8jeh7  
    Next @s2y~0}#  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. pIX`MlBdF  
    Dim nameArray() As String, sampName As String e^D]EA]%  
    nameArray = Split(fList(0)," 0-0.txt") 3/n5#&c\4  
    sampName  = nameArray(0) N<injx  
    Print "" )I.$=s  
    Print "Sample name: " & Chr(9) & sampName omBoo5e  
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    'Open an output file and write the FRED header data /s}}&u/  
    Dim outFile As String W:L AP R  
    outFile = cDir & sampName & "_FRED.txt" Q$@I"V&G.  
    Open outFile For Output As #1 yO~Ig `w  
    Print #1, "type bsdf_data" u:_,GQ )\  
    Print #1, "format angles=deg bsdf=value scale=1" jtc]>]6i  
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    'Loop the file list, skip the two header lines and write the remaining data to file kpN)zxfk  
    Dim lineArray() As String, curLine As Long 7O-x<P;  
    For Each curFile In fList w&T9;_/  
        Print "Merging data from file " & curFile @2 fg~2M1  
        ReadFile( cDir & curFile, lineArray ) q5)O%l!  
        For curLine = 2 To UBound(lineArray) 5"O.,H}  
            Print #1, lineArray(curLine) W|63Ir67  
        Next x+@rg];m  
    Next 4@# `t5H  
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    'Close the output file o
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    Close #1 %M|hA#04vZ  

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    Print "Finished merging RPC data for sample " & sampName P me^l%M  
    Print "FRED formatted data file: " & Chr(9) & outFile eV?2LtT#5  
End Sub y/ef>ZZ  
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'Utility function to read the contents of a file into an array of strings. [:SWi1cK2  
Function ReadFile(ByVal fileName As String, _ 338k?nHxv  
                  ByRef lineArray() As String) As Long 7\Y0z  
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    ReadFile = -1 %aVq+kC h  
    Dim oFSO As Object -4{<=y?"a  
    Set oFSO = CreateObject("Scripting.FileSystemObject") CdjI`  
    Erase lineArray 5uj?#)N  
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    Dim fid As Long Vb]=B~^`  
    If oFSO.fileexists( fileName ) Then $C$V%5aA  
        fid = FreeFile() mb^~qeRQ  
        Open fileName For Input As fid +*/Zu`kzX  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) #fn)k1  
        Close fid @O^6&\s>  
    End If [~c|mOk  
    Set oFSO = Nothing &powy7rR  
    Return UBound( lineArray ) XYOC_.f1  
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End Function 5IjGm  
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Sub GetFileList( ByVal in_dir As String, _ j/c&xv7=  
                 ByRef in_flist() As String ) eF-."1  
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    'Redimension the file list array ^EQ<SCh  
    Erase in_flist ,G?WAOy,  
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    'Tracks how many files are found (2E\p  
    Dim fCount As Long T;a}#56{^  
    fCount = 0 tGE$z]1c@  
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    'Recurse directory and search for text files u(F_oZ~  
    Dim f As String ~t~k2^)|"  
    f = Dir$(in_dir & "*.txt") fW1CFRHH  
    While f <> "" %axh`xK#  
        ReDim Preserve in_flist(fCount) C]`$AqKl  
        in_flist(fCount) = f ,77d(bR<  
        fCount += 1 A>
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        f = Dir$() ?(F6#"
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    Wend j[G  
    ReDim Preserve in_flist(fCount-1) 17"uf.G  
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End Sub Zbt.t]N