[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： ]'q<wPi  
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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。 Xk$lQMwZ  
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背景： 9':$!Eoq  
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。 T_WQzEL^  
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。 ?x97q3I+]  
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步骤 O]>`B
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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。 YaU A}0cW  
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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） ZE^de(Fm  
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 %
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例如下所示： xcig'4L  
Sample name:  EDF-C1-56 _,^sI%  
Merging data from file EDF-C1-56 0-0.txt H &JKja}`  
Finished merging RPC data for sample EDF-C1-56 DYS(ZY)4  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt |zMQe}R@%  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 !NCT) #G`  
a. 创建一个新的散射库 HD ~9EK~  
b. 散射模型命名 qU}DOL|  
c. 改变散射模型为“Tabulated BSDF”. 4]bTO  
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 ） E !8y|_(j  
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。 IjNm/${$  
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， AZa3!e/1  
g. 点击OK T*IudxW  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 MD7[}cB  
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脚本代码： ?P5D!b:(  
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'#Language "WWB-COM" { at; U@o  
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Option Explicit ,J|};s+  
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Sub Main NQG"}=KA  
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    'Cleanup vzw\f  
    ClearOutputWindow() sR6(8  
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    Print "Merging RPC Photonics BSDF Data Files" t]x HM  
    SetTextColor(255,0,0) ;Y"J j  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." 1pV"<,t  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." C$bK!]a  
    SetTextColor(0,0,0) DB0xIP~i,?  
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    'Current directory of this script (should be the same as the text files being merged) ^tah4QmUA  
    Dim cDir As String 3 *G=U  
    cDir = MacroDir$ & "\" -K jCPc  
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    'Array which will be populated with the list of files to be merged
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    Dim fList() As String, curFile As String L4NC-  
    GetFileList( cDir, fList ) 8X%;29tow  
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    Print "" U0rz 4fxc  
    Print "Files found for merging:" pQp}HD!-  
    For Each curFile In fList J.-#:OZ  
        Print Chr(9) & curFile pk/
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    Next -l\@50,D  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. eN$~@'w  
    Dim nameArray() As String, sampName As String B0Z@ Cf  
    nameArray = Split(fList(0)," 0-0.txt") 4nY2v['m0  
    sampName  = nameArray(0) =3"Nn4Z  
    Print "" j.z#fU  
    Print "Sample name: " & Chr(9) & sampName 6+It>mnR  
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    'Open an output file and write the FRED header data @ +7'0[y?  
    Dim outFile As String %=]{~5f>  
    outFile = cDir & sampName & "_FRED.txt" 1t)6wk N  
    Open outFile For Output As #1 >$?Z&7Lv  
    Print #1, "type bsdf_data" EgY]U1{  
    Print #1, "format angles=deg bsdf=value scale=1" [J^,_iN[.  
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    'Loop the file list, skip the two header lines and write the remaining data to file u4S3NLG)  
    Dim lineArray() As String, curLine As Long &8;mcM//4  
    For Each curFile In fList qg>i8V  
        Print "Merging data from file " & curFile M6e"4Gh  
        ReadFile( cDir & curFile, lineArray ) tSg#2  
        For curLine = 2 To UBound(lineArray) &pCKz[Yf+  
            Print #1, lineArray(curLine) '
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        Next I@hC$o  
    Next snyx$Qx(  
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    'Close the output file RH`m=?~J,  
    Close #1 WaHTzIa[  
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    Print "Finished merging RPC data for sample " & sampName G q8/xxt  
    Print "FRED formatted data file: " & Chr(9) & outFile 7 724,+2N  
End Sub 04(h!@!g:  
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'Utility function to read the contents of a file into an array of strings. 3*FktXmI}  
Function ReadFile(ByVal fileName As String, _ 9oaq%Sf  
                  ByRef lineArray() As String) As Long N%T-Q9k  
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    ReadFile = -1 `xtN+y F  
    Dim oFSO As Object jReI+ pS  
    Set oFSO = CreateObject("Scripting.FileSystemObject") o?b"B+#  
    Erase lineArray i}q6^;uTF  
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    Dim fid As Long qOng?(I  
    If oFSO.fileexists( fileName ) Then P[Qr[74)  
        fid = FreeFile() u^{Q|o:=x  
        Open fileName For Input As fid A$-{WN.W  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) 9_HEImk  
        Close fid [*1c.&%(  
    End If QZDGk4GG  
    Set oFSO = Nothing B aXzz  
    Return UBound( lineArray ) p>MX}^6  
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End Function wPV`j:?'  
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Sub GetFileList( ByVal in_dir As String, _ C~l5D4D#  
                 ByRef in_flist() As String ) {xOu*8J  
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    'Redimension the file list array ZI5UQH/  
    Erase in_flist <q_H 3|  
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    'Tracks how many files are found {8t;nsdm!  
    Dim fCount As Long [V1gj9t=,  
    fCount = 0 f(9w FT  
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    'Recurse directory and search for text files Ir]b.6B  
    Dim f As String `5>IvrzXrK  
    f = Dir$(in_dir & "*.txt") Bw{W-&$o  
    While f <> "" 0V1kZ.  
        ReDim Preserve in_flist(fCount) uz*C`T0:rj  
        in_flist(fCount) = f 8^M5u>=t;  
        fCount += 1 \Ud2]^D=  
        f = Dir$() Va9vDb6  
    Wend :S,#*rPKBK  
    ReDim Preserve in_flist(fCount-1) Q9rE_}Z  
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End Sub X5)>yM^N`