[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： S!
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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。 9WN4eC$  
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背景： MbY?4i00%h  
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。 E-Z6qZ^  
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。 ]|NwC<  
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步骤 :N!Fe7H,  
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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。 piq1cV  
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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） Pl|e?Np  
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 ;O7CahdF  
例如下所示： s^5KFK1  
Sample name:  EDF-C1-56 R7~H}>uaF  
Merging data from file EDF-C1-56 0-0.txt }
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Finished merging RPC data for sample EDF-C1-56 Jpi\n- d!  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt #H]cb#  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 A2Je*Gz  
a. 创建一个新的散射库 >T'=4n['  
b. 散射模型命名 7.hgne'<  
c. 改变散射模型为“Tabulated BSDF”. r>v_NKS]t  
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 ） C@!C='b,  
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。 US8pT|/  
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， $nR1AOm}.B  
g. 点击OK U@#YKv  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 eK_Q>;k5A  
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脚本代码： }e}J6[wP  
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'#Language "WWB-COM" S*3N6*-l"  
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Option Explicit 4;G:.k!K  
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Sub Main XXbAn-J  
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    'Cleanup |&JCf=  
    ClearOutputWindow() -{z.8p}IW  
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    Print "Merging RPC Photonics BSDF Data Files" VCOz?Y*  
    SetTextColor(255,0,0) S}=d74(/n  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." G8}w|'0m  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." J%|!KQl  
    SetTextColor(0,0,0) $umh&z/  
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    'Current directory of this script (should be the same as the text files being merged) sZ`C "1cX  
    Dim cDir As String J23Tst#s  
    cDir = MacroDir$ & "\" >T*/[{L8;  
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    'Array which will be populated with the list of files to be merged rLMjN#`^  
    Dim fList() As String, curFile As String HKA7|z9{  
    GetFileList( cDir, fList ) IooAXwOF  
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    Print "" wwnl_9a  
    Print "Files found for merging:" FBit/0  
    For Each curFile In fList #R_IF&7  
        Print Chr(9) & curFile HWe?vz$4"  
    Next ka_]s:>+  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. O 0Fw!IQk  
    Dim nameArray() As String, sampName As String -phwzR\(t  
    nameArray = Split(fList(0)," 0-0.txt") "#uXpCuw  
    sampName  = nameArray(0) HCP'V  
    Print "" xE/r:D#  
    Print "Sample name: " & Chr(9) & sampName b&k !DeE  
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    'Open an output file and write the FRED header data ia.95H;  
    Dim outFile As String $~M#msK9  
    outFile = cDir & sampName & "_FRED.txt" QdaYP  
    Open outFile For Output As #1 N?`-$C ]  
    Print #1, "type bsdf_data" [a~|{~?8  
    Print #1, "format angles=deg bsdf=value scale=1" )bc0 t]Fs  
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    'Loop the file list, skip the two header lines and write the remaining data to file 8BnI0l=\  
    Dim lineArray() As String, curLine As Long rzC\8Dd  
    For Each curFile In fList #R&Dgt  
        Print "Merging data from file " & curFile aa!o::;  
        ReadFile( cDir & curFile, lineArray ) |G.|ocj;  
        For curLine = 2 To UBound(lineArray) \iFh-?(  
            Print #1, lineArray(curLine) ;q:.&dak1  
        Next 9I0}:J;7  
    Next bYT,f.,5{  
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    'Close the output file <u\j4<p  
    Close #1 'F[m,[T%x  
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    Print "Finished merging RPC data for sample " & sampName (8C ,"Dc[0  
    Print "FRED formatted data file: " & Chr(9) & outFile Y*
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End Sub ,v;P@RL|g  
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'Utility function to read the contents of a file into an array of strings. $bQ[H[4l  
Function ReadFile(ByVal fileName As String, _ Gni<@;}  
                  ByRef lineArray() As String) As Long I f9t^T#  
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    ReadFile = -1 5c?1JH62o8  
    Dim oFSO As Object \W5fcxf  
    Set oFSO = CreateObject("Scripting.FileSystemObject") :f?};t+  
    Erase lineArray h$`P|#V&  
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    Dim fid As Long tHe
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    If oFSO.fileexists( fileName ) Then RY=B>398:  
        fid = FreeFile() 2"`R_q  
        Open fileName For Input As fid {j%'EJ5  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) ?Rlo<f:Mf  
        Close fid -ea":}/  
    End If ~Rx:X4|H  
    Set oFSO = Nothing ^8p=g-U\  
    Return UBound( lineArray ) qV^Z@N+,  
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End Function msKWb311u  
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Sub GetFileList( ByVal in_dir As String, _ tOx)t$ix  
                 ByRef in_flist() As String ) tz#Fy?pe  
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    'Redimension the file list array 5;{Q >n  
    Erase in_flist R pUq#Y:a  
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    'Tracks how many files are found G:'hT=8  
    Dim fCount As Long 9os>k*  
    fCount = 0 9V5}%4k%+  
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    'Recurse directory and search for text files R-Y07A  
    Dim f As String S>
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    f = Dir$(in_dir & "*.txt") EqW/Wxv7b  
    While f <> "" '!8'Xo@Go3  
        ReDim Preserve in_flist(fCount) (* WO<V  
        in_flist(fCount) = f Z_iVOctP  
        fCount += 1 < {1'cx  
        f = Dir$() #~(J J  
    Wend 6_KO6O7g  
    ReDim Preserve in_flist(fCount-1) u-yVc*<,  
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End Sub g\;&Z