[技术]RPC Photonics扩散片BSDF [复制链接]

摘要：
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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。 Rqr
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背景： sE&1ZJ]7  
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。 )Z)Gb~G  
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。 VS>xvF  
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步骤 |}b~YHTs  
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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。 :kFPPx
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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） S%aup(wu6  
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 :W;eW%Y  
例如下所示： W4UK?#S+  
Sample name:  EDF-C1-56 U~USwUzgY  
Merging data from file EDF-C1-56 0-0.txt &8?O ~X=/  
Finished merging RPC data for sample EDF-C1-56 t YxN^VqU  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt <@P. 'rE  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 FzNj':D  
a. 创建一个新的散射库 "By$!R-&  
b. 散射模型命名 KWojMPs  
c. 改变散射模型为“Tabulated BSDF”. huW,kk<]y  
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 ） BoxtP<C"  
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。 +abb[  
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， 7Mk>`4D'c  
g. 点击OK V~p01f"J  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 4XAs^>N+  
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脚本代码： ;dPaWS1D  
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'#Language "WWB-COM" ,J,Rup">h  
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Option Explicit F]D{[dBf  
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Sub Main ~(8fUob
 
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    'Cleanup k%X $@NP  
    ClearOutputWindow() A*~G[KC3(  
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    Print "Merging RPC Photonics BSDF Data Files" 4hc[rN,]  
    SetTextColor(255,0,0) ]YtN6Rq/  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." 7e\Jg/FU  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." :)i,K>y3i  
    SetTextColor(0,0,0) l i)6^f#  
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    'Current directory of this script (should be the same as the text files being merged) mt$rjk=  
    Dim cDir As String 0KT
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    cDir = MacroDir$ & "\" zyhM*eM.7  
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    'Array which will be populated with the list of files to be merged vbn=ywz  
    Dim fList() As String, curFile As String o$eCd{HuX  
    GetFileList( cDir, fList ) 2Z%n "z68  
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    Print "" qZ'2M.;  
    Print "Files found for merging:" lg8@^Pm$r;  
    For Each curFile In fList :"MHmm=uU8  
        Print Chr(9) & curFile AH:uG#  
    Next "w%:5~u9  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. )obgEJ7Y`l  
    Dim nameArray() As String, sampName As String &
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    nameArray = Split(fList(0)," 0-0.txt") w;yzgj:n&f  
    sampName  = nameArray(0) $y&W:  
    Print "" f}"eN/T  
    Print "Sample name: " & Chr(9) & sampName G{]RC^Zo  
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    'Open an output file and write the FRED header data ch:rAx  
    Dim outFile As String &R?`QB2/  
    outFile = cDir & sampName & "_FRED.txt" =PciL
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    Open outFile For Output As #1
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    Print #1, "type bsdf_data" /AADFa  
    Print #1, "format angles=deg bsdf=value scale=1" n@x
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    'Loop the file list, skip the two header lines and write the remaining data to file J@2wPKh?Yp  
    Dim lineArray() As String, curLine As Long `BKb60  
    For Each curFile In fList DqT<bNR1*;  
        Print "Merging data from file " & curFile `MCiybl,&P  
        ReadFile( cDir & curFile, lineArray )  $8rnf  
        For curLine = 2 To UBound(lineArray) \fUX_0k9,  
            Print #1, lineArray(curLine) Vx2/^MiXy  
        Next @B(oq1i@  
    Next 4NW!{Vw ,  
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    'Close the output file N-?5[T"  
    Close #1 %K4M`R|2]  
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    Print "Finished merging RPC data for sample " & sampName Rlk3AWl2u  
    Print "FRED formatted data file: " & Chr(9) & outFile )f|`mM4DW!  
End Sub 6"*
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'Utility function to read the contents of a file into an array of strings. ;W|NG3_y  
Function ReadFile(ByVal fileName As String, _ cJaA*sg  
                  ByRef lineArray() As String) As Long pT->qQ3;  
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    ReadFile = -1 !(F?`([A  
    Dim oFSO As Object +4_,, I  
    Set oFSO = CreateObject("Scripting.FileSystemObject") m..ajYSQ  
    Erase lineArray sdZ$3oE.  
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    Dim fid As Long DOJydYds  
    If oFSO.fileexists( fileName ) Then zplv.cf#q  
        fid = FreeFile() FHQ`T\fC$@  
        Open fileName For Input As fid olv?$]  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) nK :YbLdK,  
        Close fid vvv'!\'#  
    End If '~&W'='b;  
    Set oFSO = Nothing &L$9Ii  
    Return UBound( lineArray ) P.XT1)qo*  
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End Function 4T(d9y  
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Sub GetFileList( ByVal in_dir As String, _ F1stRZ1ZI  
                 ByRef in_flist() As String ) &]o-ZZX  
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    'Redimension the file list array 'Gl~P><e  
    Erase in_flist ;7z6B|8  
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    'Tracks how many files are found C7ivAh  
    Dim fCount As Long {IJ;)<>&VE  
    fCount = 0 %US&`BT!  
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    'Recurse directory and search for text files aYaEy(m  
    Dim f As String [[IMf-]  
    f = Dir$(in_dir & "*.txt") "a)6g0gw  
    While f <> "" iibG$?(  
        ReDim Preserve in_flist(fCount) 71R,R,  
        in_flist(fCount) = f ce\d35x!  
        fCount += 1 qX-ptsQ  
        f = Dir$() 4n1g4c-   
    Wend
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    ReDim Preserve in_flist(fCount-1) ]@Zv94Z(  
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End Sub (p%|F`