[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： tji,by#E/%  
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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。 );h\0w>3  
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背景： +k"dN^K]D  
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。 h6x+.}}  
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。  2H<?  
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步骤 Z-<v5aF  
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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。 +^+wS`Y  
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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） ke>\.|HT}  
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 BHmA*3?  
例如下所示： wZa;cg.-q  
Sample name:  EDF-C1-56 RQ,(?I*8\  
Merging data from file EDF-C1-56 0-0.txt 8"LaP3U  
Finished merging RPC data for sample EDF-C1-56 oQ;f`JC^  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt oz5o=gt7  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 F.8{ H9`  
a. 创建一个新的散射库 i`]M2Q   
b. 散射模型命名 zFi+6I$  
c. 改变散射模型为“Tabulated BSDF”. wHZ!t,g  
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 ） `A <
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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。 lO $M6l  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， GP1>h.J  
g. 点击OK H[N&Wiq/|  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 )Qxv9:X  
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脚本代码： !v;r3*#Nky  
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'#Language "WWB-COM" J|FyY)_  
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Option Explicit Z `\7B e  
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Sub Main jZ 
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    'Cleanup Y(SI`Xo[  
    ClearOutputWindow() !RcAJs'  
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    Print "Merging RPC Photonics BSDF Data Files" Zc4hjg  
    SetTextColor(255,0,0) 8]?1gDS|9O  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." Xi{(1o4%  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." k13/
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    SetTextColor(0,0,0) Y|VzeJC  
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    'Current directory of this script (should be the same as the text files being merged) :s'%IGy>:  
    Dim cDir As String #8z\i2I  
    cDir = MacroDir$ & "\" wO!hVm,Ta  
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    'Array which will be populated with the list of files to be merged a+~o: 5  
    Dim fList() As String, curFile As String G>RYQ{O  
    GetFileList( cDir, fList ) mW-@-5Wda  
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    Print "" PRz oLzr  
    Print "Files found for merging:" &\X;t|  
    For Each curFile In fList ^w12k2a  
        Print Chr(9) & curFile RrZjC  
    Next ;ZqFrHI M`  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. f.P( {PN  
    Dim nameArray() As String, sampName As String kTk?[BK  
    nameArray = Split(fList(0)," 0-0.txt") Np-D:G  
    sampName  = nameArray(0) ,){0y%c#y  
    Print "" iE
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    Print "Sample name: " & Chr(9) & sampName *tO<wp&  
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    'Open an output file and write the FRED header data ]Cz16e&=2  
    Dim outFile As String K`X2N  
    outFile = cDir & sampName & "_FRED.txt" .~U9*5d  
    Open outFile For Output As #1 *"CvB{XF&Z  
    Print #1, "type bsdf_data" zc1Zuco| R  
    Print #1, "format angles=deg bsdf=value scale=1" sR9F:  
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    'Loop the file list, skip the two header lines and write the remaining data to file PW`Tuj  
    Dim lineArray() As String, curLine As Long O+8`.  
    For Each curFile In fList Ax^'u
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        Print "Merging data from file " & curFile :9YQX(l8  
        ReadFile( cDir & curFile, lineArray ) S }n;..{  
        For curLine = 2 To UBound(lineArray) []]3"n  
            Print #1, lineArray(curLine) c'B"Onu@m*  
        Next (>K$gAQH  
    Next 31*6 ;(  
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    'Close the output file (Lo2fY5  
    Close #1 [dJ\|=  
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    Print "Finished merging RPC data for sample " & sampName XJzXxhk2  
    Print "FRED formatted data file: " & Chr(9) & outFile O$H150,Q  
End Sub 1;P\mff3Y  
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'Utility function to read the contents of a file into an array of strings. V"p<A  
Function ReadFile(ByVal fileName As String, _ EDo@J2A  
                  ByRef lineArray() As String) As Long |u{QI3#'  
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    ReadFile = -1 <n\.S  
    Dim oFSO As Object eC$v0Gtq  
    Set oFSO = CreateObject("Scripting.FileSystemObject") {Pb^Lf >  
    Erase lineArray K|G$s  
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    Dim fid As Long Z~(XyaN  
    If oFSO.fileexists( fileName ) Then x3s^u~C)(w  
        fid = FreeFile() 4iz&"~&1  
        Open fileName For Input As fid _")h %)f  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) >D/~|`=p  
        Close fid dNQSbp  
    End If a+/|O*>#  
    Set oFSO = Nothing zcKC5vqb  
    Return UBound( lineArray ) OQ7c|O  
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End Function ?i~/gjp  
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Sub GetFileList( ByVal in_dir As String, _ Fw9``{4w  
                 ByRef in_flist() As String ) wP/9z(US  
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    'Redimension the file list array h`]/3Ma*:  
    Erase in_flist 5S]P#8  
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    'Tracks how many files are found #0u69  
    Dim fCount As Long SSLshY~d  
    fCount = 0 wWw/1i:|'  
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    'Recurse directory and search for text files XyphQ}\u  
    Dim f As String  s7o*|Xv  
    f = Dir$(in_dir & "*.txt") ~5uNw*H  
    While f <> "" |V\.[F2Fe  
        ReDim Preserve in_flist(fCount) j dhml%pAd  
        in_flist(fCount) = f  -C  ON  
        fCount += 1 !2|`aa  
        f = Dir$() uS#Cb+*F  
    Wend !>y}Xq{bm3  
    ReDim Preserve in_flist(fCount-1) %_MR.J+m2  
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End Sub [|n-x3h