[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： 3Sfd|0^  

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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。 ASbIc"S6  
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背景： $}WT"K  
Thorlabs和RPC Photonics联手共同推出的新型漫射体及光束整形技术，可以解决其他技术的不足，大大改善了诸如光刻系统、有效固态照明，显示，背光，显示亮度增强和投影屏等大多数应用的性能。这项我们称之为工程漫射体（Engineered DiffusersTM）的新概念，与其他技术有许多不同。与诸如磨砂玻璃、乳色玻璃和全息元件等随机漫射体截然不同，工程漫射体要求对于每个散射中心，通常为微透镜单元，都进行控制。例如全息漫射体可以视为一组随机排列的透镜，但是通过全息曝光形成的类透镜效果只能通过静态方式进行控制：而无法单独操控每个微透镜单元，这也帮助解释了全息漫射体无法控制光的分布和轮廓。另一方面，在工程漫射体中，每个微透镜单元形成漫射体，由其凹形纵断面和在阵列中的位置所确定。同时，为了确保漫射体不受输入光束变化的影响，并且不产生衍射效果，微透镜单元的分布是随机的，根据产生相应的光束形状函数所选取的概率分布函数来确定。因此，工程漫射体同时保留了随机与确定性漫射体的优点，从而实现高性能的光束整形功能。 sF!#*Y  
FRED是美国Photon Engineering 公司开发的光学工程仿真软件，其在杂散光分析中独特的算法、高效的准确性，使其与其它同类产品相比更具优势。本案例我们重点讲述如何由RPC Photonics的BSDF数据转为FRED可识别的散射数据。 BQPmo1B  
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步骤 %9>w|%+;U+  
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1、 在http://www.rpcphotonics.com/bsdf-data-optical-diffusers/下载并解压BSDF数据到某一文件夹下，选择“Raw data”文件。 95'+8*YCY  
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2、 将     http://fred-kb.photonengr.com/wp-content/uploads/sites/2/2015/06/constructRpcScatterFile.frs脚本文件放在步骤1中的文件下。（脚本代码放在了本文的最后） GLO3v. n;  
3、 打开FRED并运行脚本文件，会输出如下“<SAMPLE>_FRED.txt”格式，<SAMPLE>即为RPC Photonics散射片数据集 %htI!b+"@  
例如下所示： 7/~=[#]*  
Sample name:  EDF-C1-56 bfA>kn0C  
Merging data from file EDF-C1-56 0-0.txt &233QRYM  
Finished merging RPC data for sample EDF-C1-56 2JK '!Ry)  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt f1aZnl  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 o.!o4&WH  
a. 创建一个新的散射库 X,w X)9]J  
b. 散射模型命名 u1X^#K$nu'  
c. 改变散射模型为“Tabulated BSDF”. nvndgeSy  
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 ） aH."| *.  
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。 9~W]D!m,  
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， ^o5;><S]  
g. 点击OK 4:rwzRDY  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 oH=?1~e  

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脚本代码： jr)M],  
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'#Language "WWB-COM" kV1L.Xg  
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Option Explicit '/xynk%)xw  
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Sub Main Ni>Ns=n  
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    'Cleanup OS#aYER~/  
    ClearOutputWindow() %}TJr]'F  
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    Print "Merging RPC Photonics BSDF Data Files" FcM)v"bF&]  
    SetTextColor(255,0,0) =i vlS  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." (NFrZ0  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." `D%i`"~Lf&  
    SetTextColor(0,0,0) 129\H< m  
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    'Current directory of this script (should be the same as the text files being merged) .;7V]B1o  
    Dim cDir As String q!Ek EW\n  
    cDir = MacroDir$ & "\" 8D)1ZUx7`  
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    'Array which will be populated with the list of files to be merged t4UK~ {gh  
    Dim fList() As String, curFile As String =7}1NeC`  
    GetFileList( cDir, fList ) _{'[Uf/l  
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    Print "" AwG0E`SU  
    Print "Files found for merging:" 8i[TeW"  
    For Each curFile In fList P0m9($JBD  
        Print Chr(9) & curFile S~:uOm2t\  
    Next g "Du]_,  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. [4#HuO@h  
    Dim nameArray() As String, sampName As String ~4+Y BN  
    nameArray = Split(fList(0)," 0-0.txt") _fk}d[q0  
    sampName  = nameArray(0) 7u;N/@  
    Print "" VX8rM!3  
    Print "Sample name: " & Chr(9) & sampName +H&/C1u  
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    'Open an output file and write the FRED header data b|AjB:G  
    Dim outFile As String # l9VTzi  
    outFile = cDir & sampName & "_FRED.txt" z$^wCd:  
    Open outFile For Output As #1 H,TApF89A  
    Print #1, "type bsdf_data" MuWZf2C  
    Print #1, "format angles=deg bsdf=value scale=1" J\+fkN<.  
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    'Loop the file list, skip the two header lines and write the remaining data to file yL asoh  
    Dim lineArray() As String, curLine As Long >8{w0hh;  
    For Each curFile In fList xKE=$SV(  
        Print "Merging data from file " & curFile BC!) g+8  
        ReadFile( cDir & curFile, lineArray ) \h'7[vkr  
        For curLine = 2 To UBound(lineArray) hkl0
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            Print #1, lineArray(curLine) J=Kv-@I>E  
        Next <xeB9  
    Next \LJ!X3TZ  
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    'Close the output file >QYx9`x&  
    Close #1 F-ZTy"z  
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    Print "Finished merging RPC data for sample " & sampName j_,/U^Ws|f  
    Print "FRED formatted data file: " & Chr(9) & outFile xkFa  
End Sub Lbo3fwW  
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'Utility function to read the contents of a file into an array of strings. 8 !:2:  
Function ReadFile(ByVal fileName As String, _ [ p,]/ ^ N  
                  ByRef lineArray() As String) As Long ??e|ec2%  
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    ReadFile = -1 8Y8bFWuc  
    Dim oFSO As Object )
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    Set oFSO = CreateObject("Scripting.FileSystemObject") #f(tzPD  
    Erase lineArray ;/V])4=  
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    Dim fid As Long V?yQm4  
    If oFSO.fileexists( fileName ) Then H.iCYD_=  
        fid = FreeFile()  g4q{ ]  
        Open fileName For Input As fid vbJdhaf  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) dpE^BWv3  
        Close fid 7R[7
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    End If o% Q7 el$f  
    Set oFSO = Nothing R%r25_8  
    Return UBound( lineArray ) 4_>;|2  
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End Function .n_Z0&i/w  
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Sub GetFileList( ByVal in_dir As String, _ H[:lQ\  
                 ByRef in_flist() As String ) -ewR:Y@j  
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    'Redimension the file list array tkm@&e=e%  
    Erase in_flist %x,HQNRDU  
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    'Tracks how many files are found c]1AM)xo  
    Dim fCount As Long !oi {8X@  
    fCount = 0 Z2*?a|3  
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    'Recurse directory and search for text files sa<\nH$_X  
    Dim f As String 4sSw7`  
    f = Dir$(in_dir & "*.txt") %I`'it2d  
    While f <> "" zQO 1%g  
        ReDim Preserve in_flist(fCount) fzVN;h
 
        in_flist(fCount) = f 9Bpb?  
        fCount += 1 WF~x`w&\  
        f = Dir$() :''Swi<H  
    Wend \kKd:C{  
    ReDim Preserve in_flist(fCount-1) 78:x{1nUM[  
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End Sub Ok)f5")N %