[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： et]*5Y6  
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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。 <FK7Rz:4T  
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背景： c\4n7m,y  
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。 Bv@m)$9\+3  
FRED是美国Photon Engineering 公司开发的光学工程仿真软件，其在杂散光分析中独特的算法、高效的准确性，使其与其它同类产品相比更具优势。本案例我们重点讲述如何由RPC Photonics的BSDF数据转为FRED可识别的散射数据。 HNuwq\w  
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步骤 PvT8XSlTx!  
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1、 在http://www.rpcphotonics.com/bsdf-data-optical-diffusers/下载并解压BSDF数据到某一文件夹下，选择“Raw data”文件。 pr0V)C6  
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2、 将     http://fred-kb.photonengr.com/wp-content/uploads/sites/2/2015/06/constructRpcScatterFile.frs脚本文件放在步骤1中的文件下。（脚本代码放在了本文的最后） {Rj'=%h  
3、 打开FRED并运行脚本文件，会输出如下“<SAMPLE>_FRED.txt”格式，<SAMPLE>即为RPC Photonics散射片数据集 TcfBfscU  
例如下所示： -;`W"&`ss  
Sample name:  EDF-C1-56 ?s"v0cg+  
Merging data from file EDF-C1-56 0-0.txt #1b
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Finished merging RPC data for sample EDF-C1-56 }5tn  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt Eq<#pX6  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 0RSa{iS*A  
a. 创建一个新的散射库 C aJ
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b. 散射模型命名 2aje$w-  
c. 改变散射模型为“Tabulated BSDF”. nG%j4r ;  
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 ） -X}R(.}x  
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。 ]VYl Eqe  
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， a@jP^VVk  
g. 点击OK !Z'm@,+  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 M7>\Qk  
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脚本代码： L2h+[f  
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'#Language "WWB-COM" F_Pd\Aq8  
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Option Explicit 86I*
 
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Sub Main Go67VqJr  
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    'Cleanup kv4J@  
    ClearOutputWindow() B&$89]gs|  
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    Print "Merging RPC Photonics BSDF Data Files" _/=ZkI5  
    SetTextColor(255,0,0) 0Yjy  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." PYf`a`dH  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." )yK!qu  
    SetTextColor(0,0,0) -?'CUm*Od  
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    'Current directory of this script (should be the same as the text files being merged) `3:%F>  
    Dim cDir As String D_)vGvv3;.  
    cDir = MacroDir$ & "\" uR%H"f  
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    'Array which will be populated with the list of files to be merged fytx({I .a  
    Dim fList() As String, curFile As String ,'673PR  
    GetFileList( cDir, fList ) .0|J+D  
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    Print "" /YbL{G )j}  
    Print "Files found for merging:" E)E!  
    For Each curFile In fList w8i!Qi#y5D  
        Print Chr(9) & curFile Z%R%D*f@y  
    Next gZUy0`E  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. $S}x'F!4_  
    Dim nameArray() As String, sampName As String VfwD{+5  
    nameArray = Split(fList(0)," 0-0.txt") ;R!
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    sampName  = nameArray(0) p o`$^TB^+  
    Print "" XL3h ;$,  
    Print "Sample name: " & Chr(9) & sampName K0g:Q*J-  
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    'Open an output file and write the FRED header data jb2:O,+!  
    Dim outFile As String [s2V-'2  
    outFile = cDir & sampName & "_FRED.txt" q':wSu u  
    Open outFile For Output As #1 kI'A` /Bl  
    Print #1, "type bsdf_data" M::iU_  
    Print #1, "format angles=deg bsdf=value scale=1" 9gg,Dy  
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    'Loop the file list, skip the two header lines and write the remaining data to file \G@6jn1G(  
    Dim lineArray() As String, curLine As Long d"UW38K{  
    For Each curFile In fList ,]mwk~HeF  
        Print "Merging data from file " & curFile | dwxe
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        ReadFile( cDir & curFile, lineArray ) n4 @a`lN5g  
        For curLine = 2 To UBound(lineArray) jZ!JXmVV  
            Print #1, lineArray(curLine) '5U$`Xe1  
        Next SEIu4 l$E  
    Next Y(zN  
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    'Close the output file ^^SfIK?p  
    Close #1 !f
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    Print "Finished merging RPC data for sample " & sampName 8!GLw-kb  
    Print "FRED formatted data file: " & Chr(9) & outFile tJPRR_nZv  
End Sub ]P$DAi  
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'Utility function to read the contents of a file into an array of strings. N08n/u&cr,  
Function ReadFile(ByVal fileName As String, _ Ne7{{1  
                  ByRef lineArray() As String) As Long }GDG$QI]K&  
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    ReadFile = -1 NCFV
 
    Dim oFSO As Object ; ,<J:%s  
    Set oFSO = CreateObject("Scripting.FileSystemObject") S "Pj1  
    Erase lineArray v|(b,J3  
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    Dim fid As Long jYX9;C;J  
    If oFSO.fileexists( fileName ) Then OX/.v?
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        fid = FreeFile() '5/}MMT  
        Open fileName For Input As fid B
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        lineArray = Split(Input(LOF(fid), fid), vbCrLf) DS}rFU  
        Close fid u^zitW!X$  
    End If
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    Set oFSO = Nothing _|B&v  
    Return UBound( lineArray ) y32++b!  
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End Function u7&'3ef  
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Sub GetFileList( ByVal in_dir As String, _ oz6+rM6MY  
                 ByRef in_flist() As String ) YG~ o  
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    'Redimension the file list array (Q8?)  
    Erase in_flist -wQ^oOJ  
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    'Tracks how many files are found `uZv9I"  
    Dim fCount As Long +`zi>=  
    fCount = 0 9m!!b{  
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    'Recurse directory and search for text files 1D
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    Dim f As String ioNa~F&  
    f = Dir$(in_dir & "*.txt") Jrd4a~XP  
    While f <> "" `m3QT3B  
        ReDim Preserve in_flist(fCount) >2CusT2  
        in_flist(fCount) = f A1QI4.K  
        fCount += 1 QrckTO  
        f = Dir$() Wt9iL  
    Wend RC{Z)M{~  
    ReDim Preserve in_flist(fCount-1) aZj
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End Sub 04guud }