[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： }{iR+MX  
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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。 {y<_S]0  
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背景： f$2lq4P{  
Thorlabs和RPC Photonics联手共同推出的新型漫射体及光束整形技术，可以解决其他技术的不足，大大改善了诸如光刻系统、有效固态照明，显示，背光，显示亮度增强和投影屏等大多数应用的性能。这项我们称之为工程漫射体（Engineered DiffusersTM）的新概念，与其他技术有许多不同。与诸如磨砂玻璃、乳色玻璃和全息元件等随机漫射体截然不同，工程漫射体要求对于每个散射中心，通常为微透镜单元，都进行控制。例如全息漫射体可以视为一组随机排列的透镜，但是通过全息曝光形成的类透镜效果只能通过静态方式进行控制：而无法单独操控每个微透镜单元，这也帮助解释了全息漫射体无法控制光的分布和轮廓。另一方面，在工程漫射体中，每个微透镜单元形成漫射体，由其凹形纵断面和在阵列中的位置所确定。同时，为了确保漫射体不受输入光束变化的影响，并且不产生衍射效果，微透镜单元的分布是随机的，根据产生相应的光束形状函数所选取的概率分布函数来确定。因此，工程漫射体同时保留了随机与确定性漫射体的优点，从而实现高性能的光束整形功能。 i"JF~6c<  
FRED是美国Photon Engineering 公司开发的光学工程仿真软件，其在杂散光分析中独特的算法、高效的准确性，使其与其它同类产品相比更具优势。本案例我们重点讲述如何由RPC Photonics的BSDF数据转为FRED可识别的散射数据。 K\?vTgc(  
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步骤 xFg=Tyq:  
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1、 在http://www.rpcphotonics.com/bsdf-data-optical-diffusers/下载并解压BSDF数据到某一文件夹下，选择“Raw data”文件。 diTzolY7  
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2、 将     http://fred-kb.photonengr.com/wp-content/uploads/sites/2/2015/06/constructRpcScatterFile.frs脚本文件放在步骤1中的文件下。（脚本代码放在了本文的最后） :&_@U$  
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 CZ]+B8Pl(x  
例如下所示： >{m>&u;Cc  
Sample name:  EDF-C1-56 i}HF
  
Merging data from file EDF-C1-56 0-0.txt A\4Gq  
Finished merging RPC data for sample EDF-C1-56
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FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt 3*8#cSQ/6o  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 N.&)22<m9  
a. 创建一个新的散射库 DCwldkdJN  
b. 散射模型命名 Q8\Ks|u]  
c. 改变散射模型为“Tabulated BSDF”. \9ap$  
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 ） ty-4yK#  
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。 Q|pz].0  
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， #wC4$y<>  
g. 点击OK |W#^L`!G  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 oxGOn('  
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脚本代码： Q@d X2  
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'#Language "WWB-COM" jriliEz;f  
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Option Explicit [bGdg  
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Sub Main t5 5k#`Z  
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    'Cleanup :+[
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    ClearOutputWindow() 
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    Print "Merging RPC Photonics BSDF Data Files" @8/-^Rh*  
    SetTextColor(255,0,0) NINyg"g<  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." 6'qs=Ql  
    Print "Note: Do not run this script multiple times without deleting the output file between executions."  wl9E  
    SetTextColor(0,0,0) a<vCAFQ  
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    'Current directory of this script (should be the same as the text files being merged) :[AW  
    Dim cDir As String yYF80mnJz  
    cDir = MacroDir$ & "\" '<XG@L  
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    'Array which will be populated with the list of files to be merged W6wgX0H  
    Dim fList() As String, curFile As String Kq.)5%~>  
    GetFileList( cDir, fList ) qU=$ 0M  

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    Print "" (?J&Ar0  
    Print "Files found for merging:" -y$|EOi?  
    For Each curFile In fList zeR!Y yt!  
        Print Chr(9) & curFile (c[|k  
    Next nwV\[E  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. L4Kkbt<x  
    Dim nameArray() As String, sampName As String E5 Y92vu  
    nameArray = Split(fList(0)," 0-0.txt") AZtZa'hbkQ  
    sampName  = nameArray(0) ~Jq<FVK  
    Print "" D+"5R5J",  
    Print "Sample name: " & Chr(9) & sampName )8LCmvQ  
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    'Open an output file and write the FRED header data *+Q,b^N  
    Dim outFile As String vsES`  
    outFile = cDir & sampName & "_FRED.txt" h^[K= J  
    Open outFile For Output As #1 - d>)  
    Print #1, "type bsdf_data" n]_8!NU  
    Print #1, "format angles=deg bsdf=value scale=1" lfWxdi  
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    'Loop the file list, skip the two header lines and write the remaining data to file 
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    Dim lineArray() As String, curLine As Long c t,p?[Q  
    For Each curFile In fList 3:);vh!  
        Print "Merging data from file " & curFile {mueP6Gz@J  
        ReadFile( cDir & curFile, lineArray ) t;E-9`N  
        For curLine = 2 To UBound(lineArray) Pm;"Y!S<  
            Print #1, lineArray(curLine) =">O;L.xj  
        Next @gs Kb*,  
    Next zf2]|]*xz  
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    'Close the output file ,=z8aiUu  
    Close #1 i}M&1
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    Print "Finished merging RPC data for sample " & sampName 3pq&TYQU  
    Print "FRED formatted data file: " & Chr(9) & outFile n;!t?jnf.  
End Sub P3@
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'Utility function to read the contents of a file into an array of strings. [\. ho9  
Function ReadFile(ByVal fileName As String, _ %'EOFv]  
                  ByRef lineArray() As String) As Long ~f){`ZJc  
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    ReadFile = -1 %:((S]vAi  
    Dim oFSO As Object Po=)jkW  
    Set oFSO = CreateObject("Scripting.FileSystemObject") I[&z#foN=w  
    Erase lineArray ,R*ru*  
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    Dim fid As Long 30[?XVI&  
    If oFSO.fileexists( fileName ) Then >*Y~I0>  
        fid = FreeFile() D<Ads  
        Open fileName For Input As fid zD2Bhta y  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) 8ae]tX5$  
        Close fid Lsuc*Ps  
    End If R-hqaEB  
    Set oFSO = Nothing J&Le*R'  
    Return UBound( lineArray ) 7c<2oTN'  
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End Function UZ&bT'>;9g  
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Sub GetFileList( ByVal in_dir As String, _ a<c %Xy/  
                 ByRef in_flist() As String ) qFf'RgUtP  
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    'Redimension the file list array C6O1ype  
    Erase in_flist RR^I*kRH  
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    'Tracks how many files are found \asF~P  
    Dim fCount As Long ToDN^qE+  
    fCount = 0 Q)HVh[4  
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    'Recurse directory and search for text files gwR ^Z{  
    Dim f As String JTl 37j  
    f = Dir$(in_dir & "*.txt") q^Oq
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    While f <> "" Vx-HW;,  
        ReDim Preserve in_flist(fCount) In=3#u ,M  
        in_flist(fCount) = f \wO)w@"  
        fCount += 1 }"Y]GH4Y  
        f = Dir$() -Qqb/y  
    Wend #.a4}ya19  
    ReDim Preserve in_flist(fCount-1) 3"!2C,3c#  
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End Sub 5K{(V^88F