[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： ^,FG9  
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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。 #XB3Wden2  
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背景： kjB'WzZ8  
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。 9Kgyt  
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。 /8nUecr  
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步骤 K=E+QvSG  
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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。 d:>'c=y  
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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） <SQR";  
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 i*$~uuY  
例如下所示： (6NDY5h~=n  
Sample name:  EDF-C1-56 z^jmf_  
Merging data from file EDF-C1-56 0-0.txt Kf}*Ij  
Finished merging RPC data for sample EDF-C1-56 N)Q.P'`N  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt HV-;?5  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 b/Ma,}  
a. 创建一个新的散射库 w4CcdpR  
b. 散射模型命名 7U1M;@y  
c. 改变散射模型为“Tabulated BSDF”. sD2,!/'  
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 ） 4nP4F+  
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nY|S{L  
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， x?lRObHK  
g. 点击OK oU @!R  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 IVZUB*wv)b  
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脚本代码： j|`lOH8  
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'#Language "WWB-COM" I)vR  
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Option Explicit qg1\ABH  
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Sub Main m@+QC$6S  
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    'Cleanup >ov#\  
    ClearOutputWindow() 0^nF: F  
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    Print "Merging RPC Photonics BSDF Data Files" =+Odu  
    SetTextColor(255,0,0) 4c{j9mh  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." BqHqS  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." +boL?Ix+  
    SetTextColor(0,0,0) s]6;*mI2  
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    'Current directory of this script (should be the same as the text files being merged) l0URJRK{*  
    Dim cDir As String "S6";G^I  
    cDir = MacroDir$ & "\" n1JV)4Mv  
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    'Array which will be populated with the list of files to be merged \'[tfSB  
    Dim fList() As String, curFile As String ]+m2pEO  
    GetFileList( cDir, fList ) =M4:nt  
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    Print "" KS$"Re$  
    Print "Files found for merging:" 8> $=p4bf  
    For Each curFile In fList  <82&F  
        Print Chr(9) & curFile mDZA\P_  
    Next hY%} x5ntU  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. k'N``.  
    Dim nameArray() As String, sampName As String iu*&Jz)D>  
    nameArray = Split(fList(0)," 0-0.txt") febn?|@  
    sampName  = nameArray(0) RXcN<Y&  
    Print "" U{Oo@ztT  
    Print "Sample name: " & Chr(9) & sampName /5"T46jD  
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    'Open an output file and write the FRED header data [kqtkgK$j2  
    Dim outFile As String ~Js kA5h|&  
    outFile = cDir & sampName & "_FRED.txt" &fWC-|  
    Open outFile For Output As #1 %Cqp88]  
    Print #1, "type bsdf_data" <]KQ$8dtD  
    Print #1, "format angles=deg bsdf=value scale=1" <)~-]  
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    'Loop the file list, skip the two header lines and write the remaining data to file ABe25Sus  
    Dim lineArray() As String, curLine As Long kh=<M{-t  
    For Each curFile In fList z80FMul
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        Print "Merging data from file " & curFile Sew*0S(  
        ReadFile( cDir & curFile, lineArray ) irq{ 21  
        For curLine = 2 To UBound(lineArray) k+?gWZ\  
            Print #1, lineArray(curLine) 9_jiUZFje  
        Next l4r>#n\yj  
    Next +swTMR  
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    'Close the output file 3(t,x  
    Close #1 lN:;~;z_  
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    Print "Finished merging RPC data for sample " & sampName ty#6%  
    Print "FRED formatted data file: " & Chr(9) & outFile ?<W|Ya  
End Sub dL'oKh,  
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'Utility function to read the contents of a file into an array of strings.
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Function ReadFile(ByVal fileName As String, _ ,"gPd!HD(  
                  ByRef lineArray() As String) As Long {5X,xdzR  
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    ReadFile = -1 }i^|.VZZ  
    Dim oFSO As Object +"BJjxG  
    Set oFSO = CreateObject("Scripting.FileSystemObject") 8UgogNR\  
    Erase lineArray i.Y2]1  
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    Dim fid As Long ilJ`_QN  
    If oFSO.fileexists( fileName ) Then /J_],KdU  
        fid = FreeFile() m>P\}A^N  
        Open fileName For Input As fid gYrB@W;2  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) BgT ^  
        Close fid CR9wp]-Vd  
    End If wf]?:'}  
    Set oFSO = Nothing W]7<PL*u  
    Return UBound( lineArray ) B'(zhjV  
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End Function @M-w8!.~  
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Sub GetFileList( ByVal in_dir As String, _ ~D|,$E tX4  
                 ByRef in_flist() As String ) Lhux~,EH  
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    'Redimension the file list array oNPvksdC;  
    Erase in_flist 5m0lk|`  
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    'Tracks how many files are found Q"{Dijc%  
    Dim fCount As Long pQ0*)}l,  
    fCount = 0 `4xQ#K.-  
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    'Recurse directory and search for text files Zv9JkY=+@  
    Dim f As String AQQa6Ce*  
    f = Dir$(in_dir & "*.txt") xcmg3:s  
    While f <> "" Ym\<@[3+!  
        ReDim Preserve in_flist(fCount) ^(C4Q?[2m  
        in_flist(fCount) = f @SxZ>|r-|v  
        fCount += 1 25vjn 1$sW  
        f = Dir$() ^VMCs/g6  
    Wend 62'9lriQ  
    ReDim Preserve in_flist(fCount-1) 8M,o)oH  
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End Sub Fs4shrt