[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： tQcn%CK  
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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。 oPR?Ar  
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背景： Ll0"<G2t  
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。 7kh(WtUz  
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。 >d$Sh`a6  
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步骤 !s(s^  
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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。 lAo S 9w  

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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） aui3Mq#f  
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 &HJ'//bv  
例如下所示： KU (g Zy  
Sample name:  EDF-C1-56 _Wgpk0  
Merging data from file EDF-C1-56 0-0.txt ~a` vk@8  
Finished merging RPC data for sample EDF-C1-56 }TwSSF|}3  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt [M&.'X  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 |TCg`ZS`cZ  
a. 创建一个新的散射库 GbJVw\5Z*  
b. 散射模型命名 )UAkg  
c. 改变散射模型为“Tabulated BSDF”. nsyeid*  
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 ） _?a.S8LxJZ  
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。 MUvgmJsN  
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， w4j,t  
g. 点击OK xaW9Sj0ZM  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 e~NF}9#A  
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脚本代码： T{zz3@2?  
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'#Language "WWB-COM" A!^gF~5  
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Option Explicit @]X5g8h  

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Sub Main P%Tffsl  
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    'Cleanup ^4[|&E:  
    ClearOutputWindow() %)!b254  
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    Print "Merging RPC Photonics BSDF Data Files" ~<q^4w.=7C  
    SetTextColor(255,0,0)  @t<KS&  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." 5nv1%48Ri  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." %M u$0~ct"  
    SetTextColor(0,0,0) L5A?9zum/!  
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    'Current directory of this script (should be the same as the text files being merged) zE1=*zO`  
    Dim cDir As String
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    cDir = MacroDir$ & "\" W^N|+$g>H  
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    'Array which will be populated with the list of files to be merged =w2_1F"  
    Dim fList() As String, curFile As String &20}64eW%  
    GetFileList( cDir, fList ) jRNDi_u?Wb  
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    Print "" ysFp`  
    Print "Files found for merging:" p5JRG2zt  
    For Each curFile In fList E% d3}@  
        Print Chr(9) & curFile GLr7sack  
    Next T7~Vk2o%(  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. m+9~f_}  
    Dim nameArray() As String, sampName As String C7xmk;c w  
    nameArray = Split(fList(0)," 0-0.txt") #D|n6[Y'.t  
    sampName  = nameArray(0) i4H,Ggb  
    Print "" ;cp,d~mrf  
    Print "Sample name: " & Chr(9) & sampName D%!GY1wdn  
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    'Open an output file and write the FRED header data SCo;Ek  
    Dim outFile As String 6"<q{K  
    outFile = cDir & sampName & "_FRED.txt" a+PVi  
    Open outFile For Output As #1 k`h#.B J  
    Print #1, "type bsdf_data" C9L_`[9DO  
    Print #1, "format angles=deg bsdf=value scale=1" "ot#g"  
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    'Loop the file list, skip the two header lines and write the remaining data to file yrQfPR  
    Dim lineArray() As String, curLine As Long K410.o/=-  
    For Each curFile In fList _q=ua;I&  
        Print "Merging data from file " & curFile YG J)_y  
        ReadFile( cDir & curFile, lineArray ) VQ
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        For curLine = 2 To UBound(lineArray) olca Z  
            Print #1, lineArray(curLine) rWNywxnT  
        Next SmVL?wf  
    Next = ow=3Ku  
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    'Close the output file V2LvE.Kj  
    Close #1 4rrR;V"}  
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    Print "Finished merging RPC data for sample " & sampName *I9O+/,  
    Print "FRED formatted data file: " & Chr(9) & outFile s"B+),Jod  
End Sub )>I-j$%=2  
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'Utility function to read the contents of a file into an array of strings. njckPpyb@  
Function ReadFile(ByVal fileName As String, _ OU'm0J
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                  ByRef lineArray() As String) As Long t$g@+1p4  
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    ReadFile = -1 ]_43U` [#  
    Dim oFSO As Object y7| 3]>Z  
    Set oFSO = CreateObject("Scripting.FileSystemObject") y85R"d  
    Erase lineArray ($'5xPb  
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    Dim fid As Long JsHD3  
    If oFSO.fileexists( fileName ) Then l;i/$Yu7  
        fid = FreeFile() cG,zO-H  
        Open fileName For Input As fid -Pc6W9$  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) Cf>(,rt};  
        Close fid -;*lcY*  
    End If Mh~E]8b  
    Set oFSO = Nothing 
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    Return UBound( lineArray ) % Ou'+A  
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End Function uF+0nv+  
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Sub GetFileList( ByVal in_dir As String, _ 8p_6RvG  
                 ByRef in_flist() As String )
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    'Redimension the file list array n+S&[Y  
    Erase in_flist z]R%'LGu  
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    'Tracks how many files are found ||4
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    Dim fCount As Long *USG p<iH  
    fCount = 0 {r'+icvLX  
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    'Recurse directory and search for text files U1O8u-X  
    Dim f As String ?NR&3q
 
    f = Dir$(in_dir & "*.txt") 9_fbl:qk;\  
    While f <> "" **JBZ\'  
        ReDim Preserve in_flist(fCount) Lg{M<Q)4  
        in_flist(fCount) = f |#yH,f  
        fCount += 1 xZA.<Yd^r  
        f = Dir$() u9fJ:a  
    Wend Z@}qL1  
    ReDim Preserve in_flist(fCount-1) psUT2  
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End Sub [0vqm:P