[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： ]N#%exBVo  
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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。 id=:J7!QU  
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背景： sSdnH_;&  
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。 Ug~]!L  
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。 VKtZyhK"h  
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步骤 P-25]-  
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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。 =,HxtPJ  
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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） R32A2Ml  
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 $T-Pl57  
例如下所示： mcgkNED  
Sample name:  EDF-C1-56 %7vjYvo>  
Merging data from file EDF-C1-56 0-0.txt +Dwq>3AH  
Finished merging RPC data for sample EDF-C1-56 f*HEw  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt $eQf5)5  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 I%
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a. 创建一个新的散射库 _f1~r^(/T0  
b. 散射模型命名 \]7i-[  
c. 改变散射模型为“Tabulated BSDF”. %jc"s\  
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 ） hP$v,"$  
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。 ,fR/C  
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， O_bgrXg6x  
g. 点击OK -rXo}I,VI  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 !YZ$WiPl  
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脚本代码： Lo-\;%y  
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'#Language "WWB-COM" W, YYL(L  
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Option Explicit :3h'Hr  
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Sub Main |vVcO  
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    'Cleanup jph"94  
    ClearOutputWindow() yG~7Xo5  
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    Print "Merging RPC Photonics BSDF Data Files" ~V`F5B  
    SetTextColor(255,0,0) 8Vf]K}d  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." 0[
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    Print "Note: Do not run this script multiple times without deleting the output file between executions." +ia N[F$  
    SetTextColor(0,0,0) k'b'Ay(<  
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    'Current directory of this script (should be the same as the text files being merged) M s5L7S  
    Dim cDir As String ;:l>Kac  
    cDir = MacroDir$ & "\" S1&Df%Ra  
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    'Array which will be populated with the list of files to be merged EDAVU  
    Dim fList() As String, curFile As String f0Zn3
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    GetFileList( cDir, fList ) 66jL2XU<  
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    Print "" }bM=)eUfX  
    Print "Files found for merging:" ,lUr[xzV  
    For Each curFile In fList oe,37xa4  
        Print Chr(9) & curFile gT8%?U:  
    Next -!JnyD  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. XaH%i~}3  
    Dim nameArray() As String, sampName As String _`LQnRp(  
    nameArray = Split(fList(0)," 0-0.txt") S(MVL!Lm  
    sampName  = nameArray(0) aH(B}wh{  
    Print "" }_GI%+t  
    Print "Sample name: " & Chr(9) & sampName '"~ 2xiin  
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    'Open an output file and write the FRED header data Sru}0M#M  
    Dim outFile As String stcbM  
    outFile = cDir & sampName & "_FRED.txt" w>6~ zAh  
    Open outFile For Output As #1 qQ=\R1l  
    Print #1, "type bsdf_data" @5Zg![G  
    Print #1, "format angles=deg bsdf=value scale=1" rJ7yq|^Z  
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    'Loop the file list, skip the two header lines and write the remaining data to file ,R8:Y*@P  
    Dim lineArray() As String, curLine As Long >|!s7.H/J/  
    For Each curFile In fList EKTn$k=  
        Print "Merging data from file " & curFile #G`UR  
        ReadFile( cDir & curFile, lineArray ) /_g-w93   
        For curLine = 2 To UBound(lineArray) uFH ]w]X  
            Print #1, lineArray(curLine) fBZAO  
        Next a3?D@@Qnw  
    Next DuV@^qSbG.  
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    'Close the output file a ]~Yi.H  
    Close #1 6OOdVS3\J  
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    Print "Finished merging RPC data for sample " & sampName KMo]J1o  
    Print "FRED formatted data file: " & Chr(9) & outFile H1^m>4ll9  
End Sub m.0:
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'Utility function to read the contents of a file into an array of strings. #eKg!]4-R  
Function ReadFile(ByVal fileName As String, _ . v L4@_  
                  ByRef lineArray() As String) As Long !`$xN~_  
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    ReadFile = -1 LH_rc  
    Dim oFSO As Object I&lb5'6D  
    Set oFSO = CreateObject("Scripting.FileSystemObject") <{xU.zp'  
    Erase lineArray kl/eJN'S  
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    Dim fid As Long M,V~oc5
 
    If oFSO.fileexists( fileName ) Then =k+nC)e  
        fid = FreeFile() !da[#zK  
        Open fileName For Input As fid ~EJ+<[/  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) YB&b_On,f  
        Close fid |MEu"pY)  
    End If gZ b+m  
    Set oFSO = Nothing WVa#nU^  
    Return UBound( lineArray ) P g{/tMY  
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End Function C 7e  
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Sub GetFileList( ByVal in_dir As String, _ :1/K$A)^{  
                 ByRef in_flist() As String ) GiH<6<=  
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    'Redimension the file list array byrK``f  
    Erase in_flist ~8#Ku,vEy  
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    'Tracks how many files are found 9+!1jTGSkf  
    Dim fCount As Long _5%NG 3c  
    fCount = 0 _pZaVx   
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    'Recurse directory and search for text files %;0l1X  
    Dim f As String M!Hn`_E  
    f = Dir$(in_dir & "*.txt") RD1N@sHDKc  
    While f <> "" [@RJ2q$  
        ReDim Preserve in_flist(fCount) Rfuq(DwD6  
        in_flist(fCount) = f q[rBu9  
        fCount += 1 g~#HiBgWq[  
        f = Dir$() G5K_e:i  
    Wend .PHz 
 
    ReDim Preserve in_flist(fCount-1) A"$UU6Z4  
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End Sub ]z{f)`;I