[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： |z`kFil%  
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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。 QlmZ4fT[r  
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背景： |_7AN!7j  
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。 j
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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。 et$VR:  
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步骤 9O.okU  
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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。 c[I4'x  
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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） #EO@<>I  
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 {vf"`#Q9  
例如下所示： %FDv6peH  
Sample name:  EDF-C1-56 ^D=1%@l?#  
Merging data from file EDF-C1-56 0-0.txt {H5a.+-(bE  
Finished merging RPC data for sample EDF-C1-56 tlnU2TT_f  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt :'pLuN  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 )Uk!;b  
a. 创建一个新的散射库 ~rN:4Q]/  
b. 散射模型命名 a->
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c. 改变散射模型为“Tabulated BSDF”. z~S(OM@olJ  
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 ） Pr%Y
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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。 TBGN',,  
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， ey~5DY7  
g. 点击OK yyj?hR@rZ  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 ][jW2;A  
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脚本代码： W@vt6v  
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'#Language "WWB-COM" m~#f L  
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Option Explicit Qrnc;H9)  
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Sub Main r?w^#V  
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    'Cleanup w6RB|^  
    ClearOutputWindow() 7j ]d{lD  
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    Print "Merging RPC Photonics BSDF Data Files" #%;QcDXRe  
    SetTextColor(255,0,0) VDyQv^=#  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." s?:&#  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." oV(|51(f  
    SetTextColor(0,0,0) h2b,(  
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    'Current directory of this script (should be the same as the text files being merged) rW8.bMmM  
    Dim cDir As String sUCI+)cM3  
    cDir = MacroDir$ & "\" $y0[AB|V  
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    'Array which will be populated with the list of files to be merged n7J6YtUwP  
    Dim fList() As String, curFile As String %z0;77[1I  
    GetFileList( cDir, fList ) 4Pbuv6`RK  
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    Print "" -&Cb^$.-x  
    Print "Files found for merging:" Z4^O`yS9+  
    For Each curFile In fList fbG+
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        Print Chr(9) & curFile bc?\lD$$  
    Next pdz_qj!Z  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. ji|+E`Nii  
    Dim nameArray() As String, sampName As String )2tDX=D  
    nameArray = Split(fList(0)," 0-0.txt") EDl*UG83G  
    sampName  = nameArray(0) e2~$=f-  
    Print ""
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    Print "Sample name: " & Chr(9) & sampName 0gLl>tF[H  
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    'Open an output file and write the FRED header data va`/Dp)M  
    Dim outFile As String z!M8lpIM  
    outFile = cDir & sampName & "_FRED.txt" A>?_\<Gp  
    Open outFile For Output As #1 7CK3t/
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    Print #1, "type bsdf_data" F&Bh\C)]  
    Print #1, "format angles=deg bsdf=value scale=1" xF#'+Y  
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    'Loop the file list, skip the two header lines and write the remaining data to file THVF(M4v  
    Dim lineArray() As String, curLine As Long &}:]uC  
    For Each curFile In fList yGxAur=dE  
        Print "Merging data from file " & curFile /S9(rI<'  
        ReadFile( cDir & curFile, lineArray ) T4M"s;::1  
        For curLine = 2 To UBound(lineArray) ZM6`:/lc  
            Print #1, lineArray(curLine) =T?:b8yV  
        Next B2R^oL'}  
    Next c\J?J>x
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    'Close the output file pL& Zcpx  
    Close #1 61[ 8I},V  
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    Print "Finished merging RPC data for sample " & sampName u!B6';XY  
    Print "FRED formatted data file: " & Chr(9) & outFile ?ZqvR^  
End Sub )F$<-0pT  
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'Utility function to read the contents of a file into an array of strings. |=o)|z2  
Function ReadFile(ByVal fileName As String, _ 9W7 ljUg  
                  ByRef lineArray() As String) As Long g5YDRL!Wh  
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    ReadFile = -1 @U 6jd4?)  
    Dim oFSO As Object !:GlxmtoW?  
    Set oFSO = CreateObject("Scripting.FileSystemObject") I<``d Ne9Q  
    Erase lineArray SqF `xw  
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    Dim fid As Long Bp7`W:?#"  
    If oFSO.fileexists( fileName ) Then &(Yv&jX  
        fid = FreeFile() G[bWjw86O  
        Open fileName For Input As fid vGX}zzto  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) js$L<^7  
        Close fid v
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    End If BM vG
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    Set oFSO = Nothing mnG\qsKNLK  
    Return UBound( lineArray ) (\I9eBm  
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End Function >iKbn  
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Sub GetFileList( ByVal in_dir As String, _ OpNxd]"T  
                 ByRef in_flist() As String ) zUI
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    'Redimension the file list array TdCC,/c3  
    Erase in_flist &
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    'Tracks how many files are found g0Ff$-#7  
    Dim fCount As Long e!B>M{  
    fCount = 0 8E+]yB"  
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    'Recurse directory and search for text files ,u<oAI`  
    Dim f As String 2LTMt?  
    f = Dir$(in_dir & "*.txt") .,9e~6}  
    While f <> "" Sc/\g  
        ReDim Preserve in_flist(fCount) "C/X#y   
        in_flist(fCount) = f TOx >Z  
        fCount += 1 <NYf!bx  
        f = Dir$() (>R  
    Wend Q`BK R]/  
    ReDim Preserve in_flist(fCount-1) 6/=0RTd  
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End Sub L|*0 A=6