[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： 7_ix&oVI  
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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。 qIuo8o}  
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背景： <CVX[R]U  
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。 zU!{_Ao9  
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。 "y
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步骤 X&zGgP/  
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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。 Hes!uy  
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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） t}R!i-D|HB  
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 @LI;q  
例如下所示： @FIL4sb  
Sample name:  EDF-C1-56 #tKks:eL  
Merging data from file EDF-C1-56 0-0.txt 3yRvs;nWS  
Finished merging RPC data for sample EDF-C1-56 j:cu;6|  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt VvW4!1Dl  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 bWA_a]G  
a. 创建一个新的散射库 01@WU1IN  
b. 散射模型命名 (5jKUQ8Q>  
c. 改变散射模型为“Tabulated BSDF”. AVjRhe  
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 ） s;bGg  
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。 UUfM7gq  
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， -E\G3/*51  
g. 点击OK p'LLzc##  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 fh`Y2s|:7R  
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脚本代码：  ="]r{  
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'#Language "WWB-COM" S=P}Jpq?Y;  
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Option Explicit C2R"96M7
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Sub Main O83J[YuzjN  
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    'Cleanup =b$g_+  
    ClearOutputWindow() :i>LESJq  
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    Print "Merging RPC Photonics BSDF Data Files" Z]Xa:[  
    SetTextColor(255,0,0) ]uFJ~:R  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." 5)f 'wVe  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." #8t=vb3  
    SetTextColor(0,0,0) gtH^'vFZ  
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    'Current directory of this script (should be the same as the text files being merged) iyCH)
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    Dim cDir As String x(u.(:V  
    cDir = MacroDir$ & "\" BsXF'x<U*  
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    'Array which will be populated with the list of files to be merged f ] *w1  
    Dim fList() As String, curFile As String ;s,1/ kA  
    GetFileList( cDir, fList ) $xW9))  
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    Print "" w@2NXcmw  
    Print "Files found for merging:" NUnwf h  
    For Each curFile In fList #(qvhoi7lM  
        Print Chr(9) & curFile br88b`L  
    Next ;PMPXN'z6  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. G?F!Z"S  
    Dim nameArray() As String, sampName As String #vK99S2  
    nameArray = Split(fList(0)," 0-0.txt") R{brf6,  
    sampName  = nameArray(0) R|Bi%q|4P  
    Print "" c%G~HOE=B  
    Print "Sample name: " & Chr(9) & sampName ^'N!k{x  
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    'Open an output file and write the FRED header data &56\@t^  
    Dim outFile As String )%Xp?H_  
    outFile = cDir & sampName & "_FRED.txt" A\mSS  
    Open outFile For Output As #1 }c8et'HYf  
    Print #1, "type bsdf_data" y46sL~HRv  
    Print #1, "format angles=deg bsdf=value scale=1" d>J +7ex+  
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    'Loop the file list, skip the two header lines and write the remaining data to file uUaDesz~=  
    Dim lineArray() As String, curLine As Long ;(E]mbV'=  
    For Each curFile In fList a)Ht(*/B  
        Print "Merging data from file " & curFile M&Q&be84  
        ReadFile( cDir & curFile, lineArray ) 9_*3xu<7i  
        For curLine = 2 To UBound(lineArray) @?tR-L<u  
            Print #1, lineArray(curLine) :p<:0W2!  
        Next :[?7,/w  
    Next e#6H[t  
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    'Close the output file meB9:w[m  
    Close #1 F$v^S+Ch  
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    Print "Finished merging RPC data for sample " & sampName A\/DAVnI  
    Print "FRED formatted data file: " & Chr(9) & outFile "OP$n-*@%  
End Sub sFfargl  
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'Utility function to read the contents of a file into an array of strings. Ei,
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Function ReadFile(ByVal fileName As String, _ N^`S'FVA  
                  ByRef lineArray() As String) As Long V+'zuX  
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    ReadFile = -1 &z\?A2Mw%  
    Dim oFSO As Object q2Gm8>F1y.  
    Set oFSO = CreateObject("Scripting.FileSystemObject") IH=%%AS  
    Erase lineArray 9Z2aFW9  
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    Dim fid As Long *W}nw$tnBX  
    If oFSO.fileexists( fileName ) Then q/7T-"q/G  
        fid = FreeFile() 4}Os>M{k  
        Open fileName For Input As fid A9HgABhax  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) ]R"n+LnI:=  
        Close fid ;cv\v(0  
    End If 7m(9|Y:Q.  
    Set oFSO = Nothing Fvv/#V^R  
    Return UBound( lineArray ) p|>/Hz1v  
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End Function @!\l
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Sub GetFileList( ByVal in_dir As String, _ XC[AJ!q`  
                 ByRef in_flist() As String ) z\J#d 1e  
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    'Redimension the file list array dr=KoAIxy  
    Erase in_flist fxD|
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    'Tracks how many files are found q>a/',m  
    Dim fCount As Long XKBQH(  
    fCount = 0 w\a9A#v,  
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    'Recurse directory and search for text files y5V]uQSD  
    Dim f As String Y,%G5X@S<  
    f = Dir$(in_dir & "*.txt") 40LAG  
    While f <> "" `t#Ie*  
        ReDim Preserve in_flist(fCount) JR/^Go$^  
        in_flist(fCount) = f ^@q$c  
        fCount += 1 ;cZ]^kof  
        f = Dir$() ;fY)7 '  
    Wend sv>c)L}I  
    ReDim Preserve in_flist(fCount-1) ByXcs'  
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End Sub Dmk~t="Y