[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： )Ln".Bu,  
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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。 QHZ",1F  
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背景： $Y6\m`  
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。 5[SwF&zZ  
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。 <C&|8@A0  
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步骤 E3O^Tg?j  
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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。 H( i   
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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） q/U-6A[0  
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 \(P?=] -  
例如下所示： B??07j  
Sample name:  EDF-C1-56 &;d N:F;  
Merging data from file EDF-C1-56 0-0.txt {:uv}4Z  
Finished merging RPC data for sample EDF-C1-56 kaekH*m~  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt |{YN3"qN  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 Mz6(M,hkq  
a. 创建一个新的散射库 \6SjJ]o>  
b. 散射模型命名 Yw3'9
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c. 改变散射模型为“Tabulated BSDF”. X>o9mW  
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 ） rvd$4l^  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 E
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f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， (~^fx\
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g. 点击OK dn- [Gnde  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 (4L/I  
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脚本代码： Z{0BH{23  
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'#Language "WWB-COM" +`Z1L\gmA  
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Option Explicit  '/.Dxib  
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Sub Main ~Xxmj!nOf  
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    'Cleanup /=/Ki%hh  
    ClearOutputWindow() N2}SR|.  
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    Print "Merging RPC Photonics BSDF Data Files" QE(.w dHP  
    SetTextColor(255,0,0) 7a'yO+7-)  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." A ]A{HEX  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." W%g*sc*+  
    SetTextColor(0,0,0) ;yt6Yp.6e  
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    'Current directory of this script (should be the same as the text files being merged) LBK{-(%  
    Dim cDir As String 0 jth}\9  
    cDir = MacroDir$ & "\" j HHWq>=d  
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    'Array which will be populated with the list of files to be merged +{I_%SsG  
    Dim fList() As String, curFile As String Z;.-UXat  
    GetFileList( cDir, fList ) /e'3\,2_  
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    Print "" :x\[aG9  
    Print "Files found for merging:" ]^~}/@  
    For Each curFile In fList N*-tBz  
        Print Chr(9) & curFile )r9 9zdUk  
    Next PdcIHN  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. lnZ{Ryo(  
    Dim nameArray() As String, sampName As String LlQsc{Ddf  
    nameArray = Split(fList(0)," 0-0.txt") !2L
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    sampName  = nameArray(0) :X;G]B .  
    Print "" G68KoM  
    Print "Sample name: " & Chr(9) & sampName te+}j7SU  
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    'Open an output file and write the FRED header data "Lbsq\W>  
    Dim outFile As String dEoIVy_9R  
    outFile = cDir & sampName & "_FRED.txt" ]<f)Rf">:`  
    Open outFile For Output As #1 bBjr hi  
    Print #1, "type bsdf_data" D|LO!,=b  
    Print #1, "format angles=deg bsdf=value scale=1" b' o]Y  
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    'Loop the file list, skip the two header lines and write the remaining data to file 2Xt4Rqk$  
    Dim lineArray() As String, curLine As Long )O1
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    For Each curFile In fList A5XMA|2_  
        Print "Merging data from file " & curFile ?,vLRq.  
        ReadFile( cDir & curFile, lineArray ) x>#{C,Fi  
        For curLine = 2 To UBound(lineArray) ]" 'yf;g  
            Print #1, lineArray(curLine) *d1BpR%  
        Next ;'"'|} xn  
    Next }@r23g%  
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    'Close the output file tDK@?PfKz  
    Close #1 v ccH(T  
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    Print "Finished merging RPC data for sample " & sampName &`D$w?beg  
    Print "FRED formatted data file: " & Chr(9) & outFile OdzeHpH3g  
End Sub |#TU"$;  
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'Utility function to read the contents of a file into an array of strings. 2@|`Ugjptl  
Function ReadFile(ByVal fileName As String, _ uC'-: t#  
                  ByRef lineArray() As String) As Long ;sB=f  
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    ReadFile = -1 c+:ZmrP/  
    Dim oFSO As Object Q dj(D\.  
    Set oFSO = CreateObject("Scripting.FileSystemObject") #"gt&t9Q  
    Erase lineArray ewMVUq*:  
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    Dim fid As Long n1-p/a.  
    If oFSO.fileexists( fileName ) Then @ st>#]i4  
        fid = FreeFile() S,&LH-ps  
        Open fileName For Input As fid c#OxI*,+/  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) 42Z:J 0  
        Close fid ZbFD|~[ V  
    End If R3>q]  
    Set oFSO = Nothing z74JyY  
    Return UBound( lineArray ) wLV,E,gM  
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End Function N1t4o~  
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Sub GetFileList( ByVal in_dir As String, _ !nmZ"n|}p  
                 ByRef in_flist() As String ) V._-iw]v  
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    'Redimension the file list array S<mZs;  
    Erase in_flist 0Wr<l%M)+  
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    'Tracks how many files are found S^QEctXU  
    Dim fCount As Long H=/1d.p  
    fCount = 0 W{,fpm  
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    'Recurse directory and search for text files Ia2WBs=
 
    Dim f As String }+,Q&]>~  
    f = Dir$(in_dir & "*.txt") i$Y#7^l%k  
    While f <> "" M Kyj<@[  
        ReDim Preserve in_flist(fCount) !wYN",R-  
        in_flist(fCount) = f )."ob=m  
        fCount += 1 ?^&ih:"  
        f = Dir$() ^ D0"m>3r  
    Wend gwj?.7N*k  
    ReDim Preserve in_flist(fCount-1) </I%VHP,[f  
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End Sub m$8siF{<q