[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： eC1cE  
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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。 *P_TG"^{W  
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背景： ON=xn|b4  
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。 Y A;S'dxY  
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。 MPT[f  
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步骤 sl)_HA7G  
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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。 ?^yZVmAo]  
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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） c=ZX7U  
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 %DiZ&}^Ck  
例如下所示： Jx'p\*  
Sample name:  EDF-C1-56 1{DHlyA6g  
Merging data from file EDF-C1-56 0-0.txt j88H3b
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Finished merging RPC data for sample EDF-C1-56 A }dl@  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt G $?VYC8;  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 /9[nogP  
a. 创建一个新的散射库 ecr pv+  
b. 散射模型命名 [u~#F,_ow  
c. 改变散射模型为“Tabulated BSDF”. B=9|g1e  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） ')go/y`YK  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 ,cpPXcz?,  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， YncY_Hu  
g. 点击OK lGs fs(  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 8TuOf(qE  
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脚本代码： u+S
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'#Language "WWB-COM" ]` 3;8,  
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Option Explicit `57ffQR9  
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Sub Main QarA.Ne~  
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    'Cleanup JgEpqA12  
    ClearOutputWindow() L7 qim.J  
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    Print "Merging RPC Photonics BSDF Data Files" ]_j{b
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    SetTextColor(255,0,0) J5I
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    Print "Note: Script should be located in the same folder as the BSDF TXT files." "M2HiV  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." {ImZ><xe/  
    SetTextColor(0,0,0) DN!:Rm uc  
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    'Current directory of this script (should be the same as the text files being merged) 7+@:wX\  
    Dim cDir As String w,D(zk$   
    cDir = MacroDir$ & "\" #m|AQr|  
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    'Array which will be populated with the list of files to be merged zZ
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    Dim fList() As String, curFile As String ]M>mwnt+  
    GetFileList( cDir, fList ) ,D>$N3;  
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    Print "" 7 zK%CJ  
    Print "Files found for merging:" Q+gQ"l,95  
    For Each curFile In fList 'Aai.PE:  
        Print Chr(9) & curFile |no '^  
    Next =p:D_b  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. 1+v)#Wj  
    Dim nameArray() As String, sampName As String b4i=eI8  
    nameArray = Split(fList(0)," 0-0.txt") DTPYCG&%  
    sampName  = nameArray(0) #%Uk}5;-  
    Print "" sZ7{_}B  
    Print "Sample name: " & Chr(9) & sampName !bS:!Il9=  
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    'Open an output file and write the FRED header data 4)i/B99k  
    Dim outFile As String rl[&s\[  
    outFile = cDir & sampName & "_FRED.txt" g&#.zJ[-  
    Open outFile For Output As #1 K6{{\r  
    Print #1, "type bsdf_data" 2t*@P"e!  
    Print #1, "format angles=deg bsdf=value scale=1" 0k0y'1SL  
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    'Loop the file list, skip the two header lines and write the remaining data to file u.gnvdU  
    Dim lineArray() As String, curLine As Long -BgzAxa  
    For Each curFile In fList ) j_g*<  
        Print "Merging data from file " & curFile ;}ileLTl  
        ReadFile( cDir & curFile, lineArray ) s-~Tf|  
        For curLine = 2 To UBound(lineArray) xm6cn\
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            Print #1, lineArray(curLine) V)oUSHillH  
        Next }L3kpw  
    Next |#Z:v1]"  
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    'Close the output file 1zl6Rwk^o  
    Close #1 KAT4C 4=,  
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    Print "Finished merging RPC data for sample " & sampName AbC/  
    Print "FRED formatted data file: " & Chr(9) & outFile ^?VYE26  
End Sub {Ug?k<h7|  
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'Utility function to read the contents of a file into an array of strings. %tT&/F  
Function ReadFile(ByVal fileName As String, _ !Y8us"  
                  ByRef lineArray() As String) As Long PTXy:>]M  
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    ReadFile = -1 }E+#*R3auB  
    Dim oFSO As Object `B}(Ln  
    Set oFSO = CreateObject("Scripting.FileSystemObject") N=YRY
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    Erase lineArray 9s8B>(L  
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    Dim fid As Long %qfql  
    If oFSO.fileexists( fileName ) Then DJ2EV^D+P  
        fid = FreeFile() SxdH%agM  
        Open fileName For Input As fid A
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        lineArray = Split(Input(LOF(fid), fid), vbCrLf) {L$]NQdz  
        Close fid .^6"nnfA#
 
    End If ]cdKd)  
    Set oFSO = Nothing nlQ<Aa-%  
    Return UBound( lineArray ) +1zCb=;!{  
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End Function Mhc!v, D$  
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Sub GetFileList( ByVal in_dir As String, _ jO)UK.H#  
                 ByRef in_flist() As String )  m_LW<'  
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    'Redimension the file list array BFmd`#{l  
    Erase in_flist l8/ tR  
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    'Tracks how many files are found 2It$ bz  
    Dim fCount As Long I0trHrX9  
    fCount = 0 fOs"\Y4  
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    'Recurse directory and search for text files -'*\KA@u  
    Dim f As String #05#@v8.f  
    f = Dir$(in_dir & "*.txt") (\}>+qS[  
    While f <> "" k7yQEU  
        ReDim Preserve in_flist(fCount) tkx1iBW=  
        in_flist(fCount) = f z;yb;),  
        fCount += 1 ~0aWjMc(>  
        f = Dir$() Hg\+:}k&9  
    Wend xs_l+/cZ  
    ReDim Preserve in_flist(fCount-1) mZDL=
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End Sub (F@.o1No%