[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： 3g9xTG);eA  
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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。 \Xc6K!HJM  
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背景： K/79Tb-  
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。 RzQ1Wq  
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。 Y>geP+-  
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步骤 > xkl7D  
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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。 R<{bb'  
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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） zg+78  
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 csz/[*  
例如下所示： /cF 6{0XS9  
Sample name:  EDF-C1-56 ^'!]|^  
Merging data from file EDF-C1-56 0-0.txt DxR__  
Finished merging RPC data for sample EDF-C1-56 5s_7P"&H  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt E ;65kZ  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 $UavM|  
a. 创建一个新的散射库 t%ye:  
b. 散射模型命名 Ac'[(  
c. 改变散射模型为“Tabulated BSDF”. UhYeyT  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） SkBa- *MC  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 <:0649ZB  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， dawe!w!  
g. 点击OK /R^Moj<  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 ;E>5<[aa  
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脚本代码： e  p~3e5  
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'#Language "WWB-COM" w'z?1M(*  
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Option Explicit Gf\Dc  
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Sub Main A9\m.3jo  
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    'Cleanup BM!\U 6  
    ClearOutputWindow() zOD5a=[1  
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    Print "Merging RPC Photonics BSDF Data Files" S%<RV6{aiM  
    SetTextColor(255,0,0) CwZ+Pn0  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." /KjRB_5~q}  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." U1bhd}Mo
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    SetTextColor(0,0,0) azR<Y_tw  
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    'Current directory of this script (should be the same as the text files being merged) [~9rp]<  
    Dim cDir As String RB.&,1  
    cDir = MacroDir$ & "\" l|z 'Lwwm5  
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    'Array which will be populated with the list of files to be merged S/G6NBnbS  
    Dim fList() As String, curFile As String N|K,{ p^li  
    GetFileList( cDir, fList ) L9nv05B  
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    Print "" 6*cG>I.Z  
    Print "Files found for merging:" l{F^"_
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    For Each curFile In fList R}njFQvS)  
        Print Chr(9) & curFile }VxbO8\b(  
    Next J/S 47J~  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. jjbBv~vs  
    Dim nameArray() As String, sampName As String /Y@^B,6\  
    nameArray = Split(fList(0)," 0-0.txt") u}Vc2a,WV  
    sampName  = nameArray(0) UOHU1.3$T  
    Print "" +6t<FH  
    Print "Sample name: " & Chr(9) & sampName _yY(&(]#  
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    'Open an output file and write the FRED header data HSGM&!5mW  
    Dim outFile As String ~6m-2-14q  
    outFile = cDir & sampName & "_FRED.txt" T.O^40y  
    Open outFile For Output As #1 ufAp7m@ud  
    Print #1, "type bsdf_data" Bf!i(gM  
    Print #1, "format angles=deg bsdf=value scale=1" !c-Ie~GIT  
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    'Loop the file list, skip the two header lines and write the remaining data to file Z*S 9pkWcF  
    Dim lineArray() As String, curLine As Long | n5F_RL  
    For Each curFile In fList m<)0XE6w  
        Print "Merging data from file " & curFile g.OBh_j-v  
        ReadFile( cDir & curFile, lineArray ) #R$d6N[H  
        For curLine = 2 To UBound(lineArray) 08AC9  
            Print #1, lineArray(curLine) "]J4BZD  
        Next le*mr0a
 
    Next W$LaXytmak  
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    'Close the output file CqX2R:#  
    Close #1 _"n1"%Ns  
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    Print "Finished merging RPC data for sample " & sampName 7NC"}JB&  
    Print "FRED formatted data file: " & Chr(9) & outFile }@MOkj  
End Sub U ^1Xc#Ff  
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'Utility function to read the contents of a file into an array of strings. !Cxo4Twg  
Function ReadFile(ByVal fileName As String, _ OJ8ac6cJ  
                  ByRef lineArray() As String) As Long ,ButNBv  
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    ReadFile = -1 la#f,C3_  
    Dim oFSO As Object <,p|3p3  
    Set oFSO = CreateObject("Scripting.FileSystemObject") L4`bGZl55  
    Erase lineArray Qr]xj7\@i  
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    Dim fid As Long N:'v^0  
    If oFSO.fileexists( fileName ) Then `
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        fid = FreeFile() `s#0/t  
        Open fileName For Input As fid #mg6F$E  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) x*td nor&  
        Close fid tdSy&]P  
    End If 9
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    Set oFSO = Nothing IJHNb_Cku  
    Return UBound( lineArray ) lx*"Pj9hho  
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End Function !|6M,Rk_  
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Sub GetFileList( ByVal in_dir As String, _
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                 ByRef in_flist() As String ) q[p+OpA  
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    'Redimension the file list array *sK")Q4N  
    Erase in_flist 8 tMfh  
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    'Tracks how many files are found WLGk  
    Dim fCount As Long i zJa`K  
    fCount = 0 =Q|_v}  
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    'Recurse directory and search for text files L,#ij!txS  
    Dim f As String 0'y9HE'e  
    f = Dir$(in_dir & "*.txt") 2w)[1s[  
    While f <> "" Ut:>'TwG  
        ReDim Preserve in_flist(fCount) c{4C4'GD  
        in_flist(fCount) = f :*
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        fCount += 1 lZoy(kdc  
        f = Dir$() ;=\vm"I?  
    Wend 1SIhW:C  
    ReDim Preserve in_flist(fCount-1) j3{8]D  
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End Sub S1oRMd)r