[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： coiTVDwA  
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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。 n +`(R]Q  
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背景： +TfMj1Zx  
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。 0&$e:O'v  
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。 i=#r JK=  
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步骤 [}+0NGgR  
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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。 Zj
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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） ?so3Kj6H  
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 =3^YKI  
例如下所示： [`yiD
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Sample name:  EDF-C1-56 PQlG!  
Merging data from file EDF-C1-56 0-0.txt BAx)R6kS;  
Finished merging RPC data for sample EDF-C1-56 $Vlfg51ob  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt 2sk^A ly  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 uZW ?0W  
a. 创建一个新的散射库 u%JM0180  
b. 散射模型命名 kZWc(LwA  
c. 改变散射模型为“Tabulated BSDF”. iEsI  
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 ） k$7-F3  
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。 P>0j]?RB  
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， \#lh b  
g. 点击OK 7'xT)~*$4  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 <YUc?NF  
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脚本代码： psta&u\ q  
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'#Language "WWB-COM" LrsP4G  
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Option Explicit e-]k{_wm  
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Sub Main |0b$60m$!t  
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    'Cleanup d9R0P2  
    ClearOutputWindow() T=ox;r  
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    Print "Merging RPC Photonics BSDF Data Files" {t;Q#Ou.  
    SetTextColor(255,0,0) %Jq(,u  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." FwBktuS  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." aL-V9y  
    SetTextColor(0,0,0) @433?g`2b  
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    'Current directory of this script (should be the same as the text files being merged) Z5bmqhDo[  
    Dim cDir As String :{E3H3  
    cDir = MacroDir$ & "\" H*A)U'`  
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    'Array which will be populated with the list of files to be merged <T+Pw7X   
    Dim fList() As String, curFile As String 0d9rJv}~  
    GetFileList( cDir, fList ) +VAfT\G2  
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    Print "" c_kxjzA#  
    Print "Files found for merging:" Y=vA;BE]R  
    For Each curFile In fList ]W5s!T_  
        Print Chr(9) & curFile tJ&S&[}  
    Next Zdr +{-  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. h}g _;k5R  
    Dim nameArray() As String, sampName As String ?F(t`0=  
    nameArray = Split(fList(0)," 0-0.txt") ,Uc\ Ajx  
    sampName  = nameArray(0) @Ys(j$U't  
    Print "" ceH7Rq:4W  
    Print "Sample name: " & Chr(9) & sampName %UV_ 3  
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    'Open an output file and write the FRED header data 1mFc]1W  
    Dim outFile As String z=?ainnKx  
    outFile = cDir & sampName & "_FRED.txt" qV/"30,K  
    Open outFile For Output As #1 3-hu'xSU  
    Print #1, "type bsdf_data" Gvtd )9^<  
    Print #1, "format angles=deg bsdf=value scale=1" 6
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    'Loop the file list, skip the two header lines and write the remaining data to file rQ30)5^V|  
    Dim lineArray() As String, curLine As Long zblh_6  
    For Each curFile In fList RgRyo  
        Print "Merging data from file " & curFile 85w D<bN27  
        ReadFile( cDir & curFile, lineArray ) Mf%/t HK  
        For curLine = 2 To UBound(lineArray) (|(Y;%>-v  
            Print #1, lineArray(curLine) Mff_j0D  
        Next +M-' K19  
    Next _@F4s  
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    'Close the output file 96}/;e]@  
    Close #1 ?9Fv0-g&n  
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    Print "Finished merging RPC data for sample " & sampName 8{4I6;e-  
    Print "FRED formatted data file: " & Chr(9) & outFile U5dJ
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End Sub o7DDL{iR/  
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'Utility function to read the contents of a file into an array of strings. [0m'a\YE9  
Function ReadFile(ByVal fileName As String, _ G?<L{J2"Q  
                  ByRef lineArray() As String) As Long v srce  
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    ReadFile = -1 rYJt;/RtR}  
    Dim oFSO As Object bsP:tFw>  
    Set oFSO = CreateObject("Scripting.FileSystemObject") E 7;KG^  
    Erase lineArray 5NJ@mm{0  
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    Dim fid As Long dQ/Xs.8  
    If oFSO.fileexists( fileName ) Then ^%IKlj-E  
        fid = FreeFile() h&h]z[r R  
        Open fileName For Input As fid u'yePJTE  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) Pkc4=i,`A  
        Close fid qW?^_
  
    End If ~AjbF(Ad  
    Set oFSO = Nothing @2YO_rL[  
    Return UBound( lineArray ) ]r'b(R; S  
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End Function A5ktbj&gy<  
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Sub GetFileList( ByVal in_dir As String, _ P)(Ly5$*  
                 ByRef in_flist() As String ) s]U'*?P
  
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    'Redimension the file list array P@k ;Lg"  
    Erase in_flist }9 qsPn  
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    'Tracks how many files are found 7QQ3IepP  
    Dim fCount As Long Nf<([8v;t  
    fCount = 0 @B7;
  
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    'Recurse directory and search for text files ?#J~X\5  
    Dim f As String /5U?4l(6[f  
    f = Dir$(in_dir & "*.txt") 8eWb{nuJ>  
    While f <> "" 9 r+' o#  
        ReDim Preserve in_flist(fCount) sJ3HH0e  
        in_flist(fCount) = f -']#5p l  
        fCount += 1 *5*d8;@>  
        f = Dir$() `\e@O#,^yI  
    Wend i"Ct}7i  
    ReDim Preserve in_flist(fCount-1) >'Y]C\  
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End Sub OwSr`2'9