[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： H4A+Dg,  
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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。 ,.MG&O  
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背景： t1g%o5?;  
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。 @5GP;3T  
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。 vz5RS  
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步骤 Nx z ,/d  
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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。 Ggjb86v\  
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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） D"5~-9<  
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 ~,1X>N"
  
例如下所示： NO1]JpR  
Sample name:  EDF-C1-56 )+R3C%  
Merging data from file EDF-C1-56 0-0.txt @},k\Is  
Finished merging RPC data for sample EDF-C1-56 t2<(by!  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt R_DQtLI  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 X~!?t}  
a. 创建一个新的散射库 ||NCVGJG  
b. 散射模型命名 CcETS}Q0C  
c. 改变散射模型为“Tabulated BSDF”. @Q5^Q'!  
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 ） gRSG[GMV  
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。 .<hv&t  
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， kp"cHJNx  
g. 点击OK qILr+zH  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 tJ3s#q6  
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脚本代码： #xB%v  
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'#Language "WWB-COM" h~t]WN  
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Option Explicit Ho|n\7$  
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Sub Main *z~Y*Q0  
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    'Cleanup 38^_(N  
    ClearOutputWindow() llJ)u!=5  
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    Print "Merging RPC Photonics BSDF Data Files" m? hX=  
    SetTextColor(255,0,0) !bg3  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." `{":*V   
    Print "Note: Do not run this script multiple times without deleting the output file between executions." +Oa1FvoEA  
    SetTextColor(0,0,0) dewu@  
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    'Current directory of this script (should be the same as the text files being merged) {iv=KF_S_  
    Dim cDir As String +TX]~k79Oq  
    cDir = MacroDir$ & "\" l=yO]a\QZ  
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    'Array which will be populated with the list of files to be merged *`W82V  
    Dim fList() As String, curFile As String \l~h#1|%;s  
    GetFileList( cDir, fList ) |bh:x{h  
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    Print "" T+fU+GLD  
    Print "Files found for merging:" C-7.Sa  
    For Each curFile In fList T&%>/7I>  
        Print Chr(9) & curFile 11uqs S2  
    Next =uH`EkY:  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. K;Ktx>Z/  
    Dim nameArray() As String, sampName As String LX8vVj8K  
    nameArray = Split(fList(0)," 0-0.txt") @ 9uwcM1F  
    sampName  = nameArray(0) Qk6FK]buV  
    Print "" S=o/n4@}  
    Print "Sample name: " & Chr(9) & sampName G100L}d"N  
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    'Open an output file and write the FRED header data 'ySWf,Q^  
    Dim outFile As String ,J[sg7vcv  
    outFile = cDir & sampName & "_FRED.txt" W[YtNL;  
    Open outFile For Output As #1 Z?~7#F~Z`  
    Print #1, "type bsdf_data" 7HzKjR=B  
    Print #1, "format angles=deg bsdf=value scale=1" {W-PYHZ;  
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    'Loop the file list, skip the two header lines and write the remaining data to file `VHm,g2  
    Dim lineArray() As String, curLine As Long ZnQnv@{8l  
    For Each curFile In fList P~~RK&+i  
        Print "Merging data from file " & curFile A2B&X}K|U  
        ReadFile( cDir & curFile, lineArray ) 5~qr+la  
        For curLine = 2 To UBound(lineArray) 9Y7 tI3  
            Print #1, lineArray(curLine) {MIs%w.G  
        Next {r Gx*<e  
    Next i
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    'Close the output file Tux~4W  
    Close #1 }!2|*Y  
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    Print "Finished merging RPC data for sample " & sampName *F
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    Print "FRED formatted data file: " & Chr(9) & outFile $BG9<:p  
End Sub b+{,c@1rd  
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'Utility function to read the contents of a file into an array of strings. $?
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Function ReadFile(ByVal fileName As String, _ ak<?Eu9rV  
                  ByRef lineArray() As String) As Long 2
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    ReadFile = -1 K5!k06;s  
    Dim oFSO As Object +W-sb5)  
    Set oFSO = CreateObject("Scripting.FileSystemObject") eE1w<] Eg  
    Erase lineArray n}a# b%e  
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    Dim fid As Long )5bhyzSZI  
    If oFSO.fileexists( fileName ) Then 9erTb?@S  
        fid = FreeFile() qxk1Rzm?x  
        Open fileName For Input As fid az7L0pp  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) he 9qWL&^G  
        Close fid <` HLG2  
    End If GT`:3L  
    Set oFSO = Nothing Zb3E-'
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    Return UBound( lineArray ) I8e{%PK  
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End Function i $#bg^  
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Sub GetFileList( ByVal in_dir As String, _ 0!\pS{$zB  
                 ByRef in_flist() As String ) 9^>nZ6  
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    'Redimension the file list array , En D3 |  
    Erase in_flist HtPasFrJ  
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    'Tracks how many files are found >4b-NS/}0  
    Dim fCount As Long LQ373 j-  
    fCount = 0 m'@NF--#Oq  
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    'Recurse directory and search for text files Tgc)'8A;BN  
    Dim f As String ney6N@  
    f = Dir$(in_dir & "*.txt") ?3k;Yg/  
    While f <> "" ]F
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        ReDim Preserve in_flist(fCount) vSX71  
        in_flist(fCount) = f P]bI".A8  
        fCount += 1 lt`#or"o  
        f = Dir$() ix [aS  
    Wend mtOCk 5E  
    ReDim Preserve in_flist(fCount-1) L?23Av0W  
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End Sub 8fY1~\G:\