[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： BWQ (>Z"  
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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。 \:O5,wf2  
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背景： sLB{R#Pt  
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。 9C`Fd S  
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。 .YLg^JfZ  
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步骤 Ag}>gbz~G  
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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。
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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） }`*]&I[P  
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 8R-?x/:  
例如下所示： YY$K;t{dk  
Sample name:  EDF-C1-56 9[8?'`m  
Merging data from file EDF-C1-56 0-0.txt 5 {'%trDEy  
Finished merging RPC data for sample EDF-C1-56 Cee?%NaTS  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt gLu#M:4N  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 |-2,k#|  
a. 创建一个新的散射库 #,GpZ  
b. 散射模型命名 iPI6 _h  
c. 改变散射模型为“Tabulated BSDF”. *mq+w&  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） t;ggc{  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 C>t1~^Q},9  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， : h-N  
g. 点击OK lSQANC'  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 d}IVYI  
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脚本代码： }vp\lKP  
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'#Language "WWB-COM" J/ <[irC  
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Option Explicit ]<TgBo|  
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Sub Main -/KVZ  
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    'Cleanup piY=(y&3  
    ClearOutputWindow() WG(tt.  
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    Print "Merging RPC Photonics BSDF Data Files" ezy0m}@  
    SetTextColor(255,0,0) [u/g =^+u  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." &LHQ)?  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." 8?P@<Do%  
    SetTextColor(0,0,0) >qCUs3}C{*  
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    'Current directory of this script (should be the same as the text files being merged) e9"<.:&  
    Dim cDir As String ADlPdkmym  
    cDir = MacroDir$ & "\" v8_HaA$5Y  
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    'Array which will be populated with the list of files to be merged  +'Tr>2V  
    Dim fList() As String, curFile As String )7O4j}B){  
    GetFileList( cDir, fList ) vM|?;QM  
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    Print "" [2.pZB  
    Print "Files found for merging:" ~kw[Aw3?D\  
    For Each curFile In fList 'Pr(7^  
        Print Chr(9) & curFile pA4oy  
    Next l9?]t;  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. A)s  
    Dim nameArray() As String, sampName As String YD7i6A  
    nameArray = Split(fList(0)," 0-0.txt") -=5z&) X  
    sampName  = nameArray(0) 8H3|^J  
    Print ""  2o?!m2W  
    Print "Sample name: " & Chr(9) & sampName ,W7\AY07]  
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    'Open an output file and write the FRED header data W}.;]x%1B  
    Dim outFile As String bgL`FW i3  
    outFile = cDir & sampName & "_FRED.txt" z(K[i?&  
    Open outFile For Output As #1 h+}`mi  
    Print #1, "type bsdf_data" 69TQHJ[  
    Print #1, "format angles=deg bsdf=value scale=1" k9'%8(7M:  
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    'Loop the file list, skip the two header lines and write the remaining data to file $kvF]|<bu  
    Dim lineArray() As String, curLine As Long {pE")O7~P  
    For Each curFile In fList eHm!  
        Print "Merging data from file " & curFile j+w*Absh  
        ReadFile( cDir & curFile, lineArray ) D />REC^
 
        For curLine = 2 To UBound(lineArray) 3zGxe-  
            Print #1, lineArray(curLine) Vv0dBFe  
        Next 0:Yz'k5  
    Next =-1d m+P  
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    'Close the output file M E4MZt:>  
    Close #1 $ZH$x3;  
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    Print "Finished merging RPC data for sample " & sampName _{TGO jZr  
    Print "FRED formatted data file: " & Chr(9) & outFile rhHX0+  
End Sub q --NLm@;  
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'Utility function to read the contents of a file into an array of strings. wVP{R3  
Function ReadFile(ByVal fileName As String, _ P`cEu6:  
                  ByRef lineArray() As String) As Long t8E'd:pE  
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    ReadFile = -1 yf2U-s  
    Dim oFSO As Object )g(2xUk-y  
    Set oFSO = CreateObject("Scripting.FileSystemObject") JyvXNV,  
    Erase lineArray :L&-
  
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    Dim fid As Long aM,>LKNbQ  
    If oFSO.fileexists( fileName ) Then %j^[%&pT  
        fid = FreeFile() #3f\,4K5  
        Open fileName For Input As fid =X2 Ieb  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) dNB56E)5`J  
        Close fid qXn%c"  
    End If xbxU`2/  
    Set oFSO = Nothing ?tQUZO  
    Return UBound( lineArray ) TGY^,H>J  
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End Function _6;T /_R=
 
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Sub GetFileList( ByVal in_dir As String, _ hIuKs5`  
                 ByRef in_flist() As String ) D"El6<3)h  
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    'Redimension the file list array X25cU{  
    Erase in_flist &$ia#j{l  
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    'Tracks how many files are found hvnZ 2x.?d  
    Dim fCount As Long Sx5r u?$.  
    fCount = 0 ]HgAI$aA,  
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    'Recurse directory and search for text files rgWGe6;!  
    Dim f As String J0~Ha u  
    f = Dir$(in_dir & "*.txt") '3 xvQFg  
    While f <> "" "i<i.6|  
        ReDim Preserve in_flist(fCount) O{y2tz3  
        in_flist(fCount) = f -4mUGh1dy  
        fCount += 1 U{"&Jj  
        f = Dir$() \(R(S!xr_  
    Wend Z,.*!S=?h  
    ReDim Preserve in_flist(fCount-1) rQC{"hS1  
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End Sub ]d&6 ?7 !>