[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： #}Qe{4L  
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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。 `E~"T0RX  
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背景： Z~:)hwF  
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。 =Jp:dM*  
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。 2Z; !N37U  

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步骤 |s/)lA: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。 6 ;'s9s"  
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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） EH".ki=e  
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 o0Teect=  
例如下所示： Y`gO:d8  
Sample name:  EDF-C1-56 1 -Z&/3T]  
Merging data from file EDF-C1-56 0-0.txt w,hm_aDq  
Finished merging RPC data for sample EDF-C1-56 *,u{,$}2  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt NXD-  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 bAlty}U  
a. 创建一个新的散射库 UV(`.  
b. 散射模型命名 nscnG5'{+  
c. 改变散射模型为“Tabulated BSDF”. #x 6/"Y2  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） wn"\@QvG  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 +*OAClt+]  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， q:_:E*o  
g. 点击OK zE;|MU@|  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 5$i(f8*  
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脚本代码： hq"nRH  
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'#Language "WWB-COM" "9s}1C;Me  
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Option Explicit }:?*n:g5  
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Sub Main "d}']M?-h  
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    'Cleanup I484cR2.  
    ClearOutputWindow() <\nM5-wR  
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    Print "Merging RPC Photonics BSDF Data Files" ^/%o I;O{  
    SetTextColor(255,0,0) ]prw=rD  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." rHk(@T.]  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." e'
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    SetTextColor(0,0,0) H/t0#  
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    'Current directory of this script (should be the same as the text files being merged)  }<kl3{)  
    Dim cDir As String ;{8 X+H  
    cDir = MacroDir$ & "\" <e&v[  
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    'Array which will be populated with the list of files to be merged ;\"5)S  
    Dim fList() As String, curFile As String foPM5+.G  
    GetFileList( cDir, fList ) b+Sj\3fX  
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    Print "" <IU   
    Print "Files found for merging:" (]k Q9}8  
    For Each curFile In fList @Y,t]  
        Print Chr(9) & curFile [cFD\"gJAr  
    Next ((?"2 }1r  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. 37n2
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    Dim nameArray() As String, sampName As String 4]}d'x&  
    nameArray = Split(fList(0)," 0-0.txt") %-YWn`yEm  
    sampName  = nameArray(0) BZOl&G(  
    Print "" },<Y \  
    Print "Sample name: " & Chr(9) & sampName {%6 '|<`[  
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    'Open an output file and write the FRED header data uJ|,-"~F  
    Dim outFile As String '"q+[zwv  
    outFile = cDir & sampName & "_FRED.txt" ^69(V LK  
    Open outFile For Output As #1 Tb^1#O  
    Print #1, "type bsdf_data" pVl7]_=m  
    Print #1, "format angles=deg bsdf=value scale=1" F)=<|,b1  
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    'Loop the file list, skip the two header lines and write the remaining data to file EAh|$~X  
    Dim lineArray() As String, curLine As Long  )%9:k9  
    For Each curFile In fList Tq^B>{S"  
        Print "Merging data from file " & curFile vWW Q/^  
        ReadFile( cDir & curFile, lineArray ) F" G+/c/L  
        For curLine = 2 To UBound(lineArray) cEXd#TlY~X  
            Print #1, lineArray(curLine) eVj 8u  
        Next ]}S9KP  
    Next EGRIhnED#  
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    'Close the output file ^tyqc8&  
    Close #1 * W"Pv,:  
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    Print "Finished merging RPC data for sample " & sampName PMiu "  
    Print "FRED formatted data file: " & Chr(9) & outFile J>hjIN  
End Sub TJcHqzcUc  
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'Utility function to read the contents of a file into an array of strings. R4D$)D  
Function ReadFile(ByVal fileName As String, _
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                  ByRef lineArray() As String) As Long ;S
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    ReadFile = -1 +CQIm!Sp  
    Dim oFSO As Object `^g-2~  
    Set oFSO = CreateObject("Scripting.FileSystemObject") T_\hhP~  
    Erase lineArray ](+u'8  
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    Dim fid As Long C-:|A* z  
    If oFSO.fileexists( fileName ) Then !~mPxGY  
        fid = FreeFile() fX LsLh+~D  
        Open fileName For Input As fid (-o}'l'mo  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) %Zeb#//Jz  
        Close fid BL0xSNE**  
    End If gYpFF=7j<@  
    Set oFSO = Nothing sldcI@Z  
    Return UBound( lineArray ) s2tNQtq0W  
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End Function -Lsl  
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Sub GetFileList( ByVal in_dir As String, _ S>
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                 ByRef in_flist() As String ) .L)j ql%  
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    'Redimension the file list array .%\R L/  
    Erase in_flist h?QGJ^#8  
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    'Tracks how many files are found `j6O  
    Dim fCount As Long Z4k'c+  
    fCount = 0 uY&t9L8  
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    'Recurse directory and search for text files t4zKI~cO  
    Dim f As String s_!F`[  
    f = Dir$(in_dir & "*.txt") :K*/  
    While f <> "" 9KL)5_6 M  
        ReDim Preserve in_flist(fCount) 9*a"^  
        in_flist(fCount) = f {ZUgyGE{  
        fCount += 1 7U)w\A;~  
        f = Dir$() fHF*#  
    Wend J32"Ytdo<  
    ReDim Preserve in_flist(fCount-1) cS",Bw\  
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End Sub 1mv8[^pF