[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： 3%HF"$Gg  
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RPC Photonics公司有高品质的的工程漫射体BSDF测试数据，但它对于FRED帮助甚少，下面这个步骤描述了如何利用FRED脚本转换RPC Photonics提供的TXT文件，并将数据直接应用到FRED的Tabulated scatter 散射模型。 ct o+W}k  
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背景： +ftOJFkI  
Thorlabs和RPC Photonics联手共同推出的新型漫射体及光束整形技术，可以解决其他技术的不足，大大改善了诸如光刻系统、有效固态照明，显示，背光，显示亮度增强和投影屏等大多数应用的性能。这项我们称之为工程漫射体（Engineered DiffusersTM）的新概念，与其他技术有许多不同。与诸如磨砂玻璃、乳色玻璃和全息元件等随机漫射体截然不同，工程漫射体要求对于每个散射中心，通常为微透镜单元，都进行控制。例如全息漫射体可以视为一组随机排列的透镜，但是通过全息曝光形成的类透镜效果只能通过静态方式进行控制：而无法单独操控每个微透镜单元，这也帮助解释了全息漫射体无法控制光的分布和轮廓。另一方面，在工程漫射体中，每个微透镜单元形成漫射体，由其凹形纵断面和在阵列中的位置所确定。同时，为了确保漫射体不受输入光束变化的影响，并且不产生衍射效果，微透镜单元的分布是随机的，根据产生相应的光束形状函数所选取的概率分布函数来确定。因此，工程漫射体同时保留了随机与确定性漫射体的优点，从而实现高性能的光束整形功能。 hv.33l  
FRED是美国Photon Engineering 公司开发的光学工程仿真软件，其在杂散光分析中独特的算法、高效的准确性，使其与其它同类产品相比更具优势。本案例我们重点讲述如何由RPC Photonics的BSDF数据转为FRED可识别的散射数据。 1=o|[
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步骤 Ebk9[=  
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1、 在http://www.rpcphotonics.com/bsdf-data-optical-diffusers/下载并解压BSDF数据到某一文件夹下，选择“Raw data”文件。  x&^>|'H  
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2、 将     http://fred-kb.photonengr.com/wp-content/uploads/sites/2/2015/06/constructRpcScatterFile.frs脚本文件放在步骤1中的文件下。（脚本代码放在了本文的最后） 1V
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3、 打开FRED并运行脚本文件，会输出如下“<SAMPLE>_FRED.txt”格式，<SAMPLE>即为RPC Photonics散射片数据集 %5[,U)X"  
例如下所示： nf%"7y{dd  
Sample name:  EDF-C1-56 >{/As][  
Merging data from file EDF-C1-56 0-0.txt 3$ 'eDa[  
Finished merging RPC data for sample EDF-C1-56 {:@MBA34  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt \}:RG^*m  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 *HC[LM  
a. 创建一个新的散射库 4k7 LM]  
b. 散射模型命名 E8gbm&x*  
c. 改变散射模型为“Tabulated BSDF”. fC4#b?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 ） JyiP3whW  
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。 LA +BH_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， 6x]x>:8  
g. 点击OK `S)*(s?T  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 h=a-~= 8  
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脚本代码： \jR('5DcB  
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'#Language "WWB-COM" = n>aJ(=Pd  
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Option Explicit 'gD,HX  
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Sub Main M
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    'Cleanup __mnz``/Y  
    ClearOutputWindow() \gU=B|W  
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    Print "Merging RPC Photonics BSDF Data Files" 9y$"[d27;+  
    SetTextColor(255,0,0) kO)+%'L!8  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." ~ZxFL$<'3  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." h=x{ 3P;B  
    SetTextColor(0,0,0) S7(Vc H  
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    'Current directory of this script (should be the same as the text files being merged) Qnr7Qnb
 
    Dim cDir As String e5z U`R  
    cDir = MacroDir$ & "\" th4yuDPuA  
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    'Array which will be populated with the list of files to be merged d*cAm$  
    Dim fList() As String, curFile As String <+r<3ZBA  
    GetFileList( cDir, fList ) _yH=w'8.  
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    Print "" #P,C9OQD  
    Print "Files found for merging:" yG/_k!{9  
    For Each curFile In fList {K,KIj"  
        Print Chr(9) & curFile cD5^mxd%  
    Next )a;ou>u  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. \v,mr|  
    Dim nameArray() As String, sampName As String USrBi[_ci\  
    nameArray = Split(fList(0)," 0-0.txt") =X24C'!Mpe  
    sampName  = nameArray(0) lk[BS*  
    Print "" G&DL)ePu]m  
    Print "Sample name: " & Chr(9) & sampName 7O\sQ]i6  
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    'Open an output file and write the FRED header data 9FKowF_8  
    Dim outFile As String 9{(A-  
    outFile = cDir & sampName & "_FRED.txt" Pkq
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    Open outFile For Output As #1 OtsW>L@ O(  
    Print #1, "type bsdf_data" FHv^^
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    Print #1, "format angles=deg bsdf=value scale=1" 3B^`xnV  
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    'Loop the file list, skip the two header lines and write the remaining data to file o)U4RY*  
    Dim lineArray() As String, curLine As Long ?E2$  
    For Each curFile In fList MmL)CT  
        Print "Merging data from file " & curFile &}+^*X  
        ReadFile( cDir & curFile, lineArray ) &}."sGK  
        For curLine = 2 To UBound(lineArray) 1 Vq)& N  
            Print #1, lineArray(curLine) #CcC& I :c  
        Next i^I U)\  
    Next 84|oqwZO  
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    'Close the output file 6$*\
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    Close #1 WKDa]({k%  
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    Print "Finished merging RPC data for sample " & sampName '^#=,+ A  
    Print "FRED formatted data file: " & Chr(9) & outFile _ !r]**  
End Sub #|ILeby  
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'Utility function to read the contents of a file into an array of strings. <,\Op=$l3I  
Function ReadFile(ByVal fileName As String, _ OdWZYWj  
                  ByRef lineArray() As String) As Long fk)5T
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    ReadFile = -1 9cMQ51k)E  
    Dim oFSO As Object \])-Bp,  
    Set oFSO = CreateObject("Scripting.FileSystemObject") f?[0I\V[$  
    Erase lineArray +yO^,{8SE  
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    Dim fid As Long o)}M$}4  
    If oFSO.fileexists( fileName ) Then J.;{`U=:  
        fid = FreeFile() 9=FqI50{  
        Open fileName For Input As fid ;+6TZqklQ  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) z<h?WsL  
        Close fid [i 7^a/e  
    End If POl_chq  
    Set oFSO = Nothing J 6%CF2  
    Return UBound( lineArray ) *F)+- BB  
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End Function 6{8
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Sub GetFileList( ByVal in_dir As String, _ 7JL*y\'  
                 ByRef in_flist() As String ) eX0ASI9  
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    'Redimension the file list array X) O9PQ  
    Erase in_flist ?VCM@{9  
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    'Tracks how many files are found }]K^b1Fs5  
    Dim fCount As Long R&P}\cf8T  
    fCount = 0 jph"94  
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    'Recurse directory and search for text files R|OY5@  
    Dim f As String 48p< ~#<W\  
    f = Dir$(in_dir & "*.txt") 'qt+.vd  
    While f <> "" Qi?xx')  
        ReDim Preserve in_flist(fCount) +ia N[F$  
        in_flist(fCount) = f k'b'Ay(<  
        fCount += 1 ,2*x4Gycb  
        f = Dir$() M s5L7S  
    Wend fk!P#  
    ReDim Preserve in_flist(fCount-1) WPXLN'w+  
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End Sub %!HBPLk