[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： _95V"h
 
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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。 mAz'
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背景： X=lOwPvP  
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。 Zx@{nVoYe~  
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。 k@^)>J^  
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步骤 wJi
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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。 [E+#+-n7  
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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） bX8Bn0#a+  
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 ~)ls.NXI  
例如下所示： fDf:J
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Sample name:  EDF-C1-56 U)2\=%8  
Merging data from file EDF-C1-56 0-0.txt
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Finished merging RPC data for sample EDF-C1-56 VUk2pEGO.  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt u9J;OsnHK  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 +c?1\{
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a. 创建一个新的散射库 smJ%^'x
 
b. 散射模型命名 L9(fa+$+#  
c. 改变散射模型为“Tabulated BSDF”. ?Yxk1Y4ig)  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） -W2 !_  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 r\Zz=~![<  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， s#>Bwn&b)  
g. 点击OK IZ"d s=w  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 3DbS\jja  
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脚本代码： YvRMUT  
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'#Language "WWB-COM" pPUKx=d  
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Option Explicit &Nl:  
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Sub Main v[\' M  
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    'Cleanup HsO4C)/  
    ClearOutputWindow() adRvAq]mA  
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    Print "Merging RPC Photonics BSDF Data Files" `L/\F,  
    SetTextColor(255,0,0) LNPwb1)  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." \hoYQK j  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." 1 :<f[l  
    SetTextColor(0,0,0) Ou>L|#=!  
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    'Current directory of this script (should be the same as the text files being merged) 8K=sx@l  
    Dim cDir As String '#L.w6<B  
    cDir = MacroDir$ & "\" -AWL :<  
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    'Array which will be populated with the list of files to be merged x8|sdZFxo  
    Dim fList() As String, curFile As String &z8I@^<  
    GetFileList( cDir, fList ) e@|/, W  
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    Print "" !36jtKdM  
    Print "Files found for merging:" *z&m=G\  
    For Each curFile In fList U=QfInB  
        Print Chr(9) & curFile vau0Jn%=ck  
    Next FwKT_XkY  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. R-5EztmLae  
    Dim nameArray() As String, sampName As String ] ;"blB  
    nameArray = Split(fList(0)," 0-0.txt") 2
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    sampName  = nameArray(0) u2}zRC=  
    Print "" MZ]#9/  
    Print "Sample name: " & Chr(9) & sampName 6HeZ<.d
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    'Open an output file and write the FRED header data b+7!$  
    Dim outFile As String 9O1#%  
    outFile = cDir & sampName & "_FRED.txt" 5'*v-l,[  
    Open outFile For Output As #1 #[=%+*Q  
    Print #1, "type bsdf_data" &iYy  
    Print #1, "format angles=deg bsdf=value scale=1" VjsQy
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    'Loop the file list, skip the two header lines and write the remaining data to file m$

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    Dim lineArray() As String, curLine As Long zI1-l9 o  
    For Each curFile In fList !0p_s;uu,W  
        Print "Merging data from file " & curFile pH!e<m  
        ReadFile( cDir & curFile, lineArray ) &b~if}vcb  
        For curLine = 2 To UBound(lineArray) z86[_l:  
            Print #1, lineArray(curLine) 6'E3Q=}d  
        Next Ni bOtIZ  
    Next fdk]i/*)  
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    'Close the output file Ut|G.%1Vd%  
    Close #1 *?dw`j_b >  
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    Print "Finished merging RPC data for sample " & sampName bUJ5jkZ)  
    Print "FRED formatted data file: " & Chr(9) & outFile UM[<v9NWE  
End Sub
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'Utility function to read the contents of a file into an array of strings. uj 6dP  
Function ReadFile(ByVal fileName As String, _ &\[3m^L  
                  ByRef lineArray() As String) As Long >d1g
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    ReadFile = -1 3"9'MDKH  
    Dim oFSO As Object
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    Set oFSO = CreateObject("Scripting.FileSystemObject") q4Z9;^S  
    Erase lineArray s{q)P1x  
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    Dim fid As Long AiMD"7 )c  
    If oFSO.fileexists( fileName ) Then X"'c2gaa_  
        fid = FreeFile() ~ 8hAmM  
        Open fileName For Input As fid 0qND2_  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) X}
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        Close fid cU`sA_f  
    End If ~D[5AXV`^  
    Set oFSO = Nothing IG}`~% Z  
    Return UBound( lineArray ) HZ>8@AVa\  
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End Function )+!~xL  
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Sub GetFileList( ByVal in_dir As String, _ dM|&Y6
  
                 ByRef in_flist() As String ) "w0[l"3V  
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    'Redimension the file list array e~Hx+Qp.G  
    Erase in_flist e@B
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    'Tracks how many files are found Cq-d,  
    Dim fCount As Long z@\r V@W5  
    fCount = 0 =SY5E{`4p  
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    'Recurse directory and search for text files ^Md
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    Dim f As String XI>|"*-l  
    f = Dir$(in_dir & "*.txt") =v(MdjwFl  
    While f <> "" ]yzqBb
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        ReDim Preserve in_flist(fCount) 1O<Gg<<,e  
        in_flist(fCount) = f +@ '(N  
        fCount += 1 W
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        f = Dir$() WGxe3(d  
    Wend iymOq9  
    ReDim Preserve in_flist(fCount-1) ML6V,-KU  
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End Sub v7;zce/~