[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： 5JHWt<n{P  
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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。 @U3:9~Q  
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背景： 78 w  
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。 6P3h955c  
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。 tr5j<O  
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步骤 ]5K+W  
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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。 m]vS"AdX  
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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） #dKy{Q3he  
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 pdB\D  
例如下所示： ;yajt\a  
Sample name:  EDF-C1-56 `Xz!apA  
Merging data from file EDF-C1-56 0-0.txt C1'y6{,@  
Finished merging RPC data for sample EDF-C1-56 dB6['z)2  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt \-pqqSy  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 /vq$/  
a. 创建一个新的散射库 |p!($  
b. 散射模型命名 x3g4r_  
c. 改变散射模型为“Tabulated BSDF”. Vpne-PW  
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 ）  IMr#5  
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。 .%y'q!?  
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， pHuR_U5*?  
g. 点击OK }K8e(i6z  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 9/!1J  
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脚本代码： JO*/UC>"  
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'#Language "WWB-COM" ]=VRct "  
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Option Explicit  63 'X#S  
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Sub Main ^D5Jqh)
 
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    'Cleanup q8&l%-d`  
    ClearOutputWindow() h}!9?:E  
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    Print "Merging RPC Photonics BSDF Data Files" /q+;!E
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    SetTextColor(255,0,0) J,:&U wkv  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." 4xEw2F  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." @J&korU  
    SetTextColor(0,0,0) C+uW]]~I)  
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    'Current directory of this script (should be the same as the text files being merged) /zt M'  
    Dim cDir As String PWyf3  
    cDir = MacroDir$ & "\" !ig&8:  
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    'Array which will be populated with the list of files to be merged );':aXj  
    Dim fList() As String, curFile As String tH)jEY9  
    GetFileList( cDir, fList ) ?"r=08  
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    Print "" ;RJ 8h x  
    Print "Files found for merging:" h#"$W;(  
    For Each curFile In fList BaW4 s4u  
        Print Chr(9) & curFile V0v,s^\H  
    Next Kc?4q=7q  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. w^ut,`yWR  
    Dim nameArray() As String, sampName As String '{UKO7  
    nameArray = Split(fList(0)," 0-0.txt") \$ipnQv  
    sampName  = nameArray(0) S@qR~_>
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    Print "" fE+zA)KX  
    Print "Sample name: " & Chr(9) & sampName O`c50yY  
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    'Open an output file and write the FRED header data Cl`i|cF\  
    Dim outFile As String !CWe1Dm  
    outFile = cDir & sampName & "_FRED.txt" q50F!yHC-  
    Open outFile For Output As #1 <kdlXS>J.  
    Print #1, "type bsdf_data" s@ r{TXEn  
    Print #1, "format angles=deg bsdf=value scale=1" 4lB??`UN  
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    'Loop the file list, skip the two header lines and write the remaining data to file vUJ;D  
    Dim lineArray() As String, curLine As Long -p&u=  
    For Each curFile In fList 8^>c_%e}  
        Print "Merging data from file " & curFile <mE`<-$  
        ReadFile( cDir & curFile, lineArray ) ^"X.aksA  
        For curLine = 2 To UBound(lineArray) g w([08  
            Print #1, lineArray(curLine) \"oZ
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        Next Z-Qp9G'   
    Next [&n[p?  
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    'Close the output file iyl i/3|  
    Close #1 B={_}
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    Print "Finished merging RPC data for sample " & sampName b&+zAt.  
    Print "FRED formatted data file: " & Chr(9) & outFile Dz: +. @k  
End Sub ^obuMQ;  
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'Utility function to read the contents of a file into an array of strings. hc3hU  
Function ReadFile(ByVal fileName As String, _ `y3'v]  
                  ByRef lineArray() As String) As Long 8x U*j  
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    ReadFile = -1 t1adS:)s  
    Dim oFSO As Object g[O?wH-a  
    Set oFSO = CreateObject("Scripting.FileSystemObject") V ql4*OJW  
    Erase lineArray {siOa%;*  
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    Dim fid As Long _-TplGSO=c  
    If oFSO.fileexists( fileName ) Then T+v*@#iJ_  
        fid = FreeFile() dtC@cK/,D  
        Open fileName For Input As fid |6*Bu1  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) iYStl  
        Close fid G;l7,1;MU:  
    End If A)&FcMO*z  
    Set oFSO = Nothing R@\}iyM  
    Return UBound( lineArray ) KGy3#r;Q
 
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End Function fY!?rZ)$  
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Sub GetFileList( ByVal in_dir As String, _ m1X7zUCy  
                 ByRef in_flist() As String ) 8%7%[WC#  
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    'Redimension the file list array 'QCIKCn<  
    Erase in_flist =%X."i1A  
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    'Tracks how many files are found !%G]~  
    Dim fCount As Long 2tq2   
    fCount = 0 Y@+Rb  
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    'Recurse directory and search for text files Z+El(f x  
    Dim f As String >|QH I d8  
    f = Dir$(in_dir & "*.txt") H#TkIFo]  
    While f <> "" /t0L%jJZ  
        ReDim Preserve in_flist(fCount) aOzIo-  
        in_flist(fCount) = f QH/py  
        fCount += 1 -+*h'zZ[<w  
        f = Dir$() Rd#R}yA  
    Wend {@InOo!4w]  
    ReDim Preserve in_flist(fCount-1) ]@&X*~c^Z  
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End Sub N[I@}j