[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： ?zex]!R  
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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。 Qo32oT[DM  
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背景： z
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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。 )pSA|Qt N  
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。 JR8|!Of@B  
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步骤 EQN)y27poW  
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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。 O uNPDq%  
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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） s_ t/  
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 +5S>"KAUt0  
例如下所示： vJxEF&X  
Sample name:  EDF-C1-56 3Q'vVNFh<  
Merging data from file EDF-C1-56 0-0.txt l`.z^+!8@  
Finished merging RPC data for sample EDF-C1-56 elAWQEus  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt Y?TS,   
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 ]DKRug5  
a. 创建一个新的散射库 FRuPv6  
b. 散射模型命名 6R,Y.srR  
c. 改变散射模型为“Tabulated BSDF”. M!+
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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 ） " i:[|7  
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。 6se8`[  
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， GF6o  
g. 点击OK u?"="-^  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 Q7rBc wm5  
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脚本代码：
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'#Language "WWB-COM" iLch3[p%  
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Option Explicit >MJ#|vO  
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Sub Main +}O -WX?  
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    'Cleanup ?HJh;96B  
    ClearOutputWindow() S=ZZ[E_~S  
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    Print "Merging RPC Photonics BSDF Data Files" ;Ax-f04gG  
    SetTextColor(255,0,0) x(._?5  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." yfK}1mx)j  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." X8VBs#tLE  
    SetTextColor(0,0,0) 0S^&A?$=  
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    'Current directory of this script (should be the same as the text files being merged) g!R7CRt%  
    Dim cDir As String \?; `_E`j  
    cDir = MacroDir$ & "\" u [._RA  
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    'Array which will be populated with the list of files to be merged y92R}e\M  
    Dim fList() As String, curFile As String Ez;Qo8  
    GetFileList( cDir, fList ) =n
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    Print "" tGgxID  
    Print "Files found for merging:" 2uOYuM[7gH  
    For Each curFile In fList ?D6uviQg  
        Print Chr(9) & curFile JcWp14~e  
    Next ]:OrGD"  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. j@>D]j  
    Dim nameArray() As String, sampName As String lFGuQLuqA{  
    nameArray = Split(fList(0)," 0-0.txt") &cL1 EQ(  
    sampName  = nameArray(0) ux<|8S  
    Print "" 4p,:}h  
    Print "Sample name: " & Chr(9) & sampName E +_n@t"  
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    'Open an output file and write the FRED header data q2*A'C  
    Dim outFile As String HEBeJ2w  
    outFile = cDir & sampName & "_FRED.txt" #73pryXV  
    Open outFile For Output As #1 [3jJQ3O,  
    Print #1, "type bsdf_data" ~Jk&!IE2  
    Print #1, "format angles=deg bsdf=value scale=1" h+}BtKA  
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    'Loop the file list, skip the two header lines and write the remaining data to file fZ$
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    Dim lineArray() As String, curLine As Long q#tUDxf(|  
    For Each curFile In fList bZ\R0[0  
        Print "Merging data from file " & curFile =#2c r:1  
        ReadFile( cDir & curFile, lineArray ) j|t=%*  
        For curLine = 2 To UBound(lineArray) qD{1X25O  
            Print #1, lineArray(curLine) Ipk;Nq  
        Next }:0_%=)N<  
    Next wb0$FZzh  
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    'Close the output file Ca|egQv  
    Close #1 |}z)>E  
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    Print "Finished merging RPC data for sample " & sampName Am<5J,<uy  
    Print "FRED formatted data file: " & Chr(9) & outFile =]%JTGdp(  
End Sub 6Ijt2c'A}  
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'Utility function to read the contents of a file into an array of strings.
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Function ReadFile(ByVal fileName As String, _ /eI|m9ke  
                  ByRef lineArray() As String) As Long `,qft[1  
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    ReadFile = -1 (xHmucmwp  
    Dim oFSO As Object F\ B/q  
    Set oFSO = CreateObject("Scripting.FileSystemObject") lL}NiN-)t  
    Erase lineArray IrMHAM5K  
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    Dim fid As Long 0$*7lQ<a#M  
    If oFSO.fileexists( fileName ) Then h} `v0E  
        fid = FreeFile() Az&>.*  
        Open fileName For Input As fid i g(O$y  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) $Zu?Gd?  
        Close fid F\m^slsu7=  
    End If .d<K`.O;  
    Set oFSO = Nothing [Fl_R[o  
    Return UBound( lineArray ) .nPOjwEx&Y  
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End Function }u_D{bz  
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Sub GetFileList( ByVal in_dir As String, _ 8A#,*@V[  
                 ByRef in_flist() As String ) W/qXQORv  
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    'Redimension the file list array o701RG~)  
    Erase in_flist ` ,\b_SFg  
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    'Tracks how many files are found '(.5!7?Qc  
    Dim fCount As Long yaR>?[h  
    fCount = 0 y98FEG#S}  
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    'Recurse directory and search for text files "t0^4=c+7  
    Dim f As String ciblj?"Wi  
    f = Dir$(in_dir & "*.txt")
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    While f <> "" ,Y:oTo=~  
        ReDim Preserve in_flist(fCount) sY;h~a0n  
        in_flist(fCount) = f 0t7N yKU  
        fCount += 1 uj8saNu  
        f = Dir$() Z[#8F&QV!m  
    Wend o%_-u +  
    ReDim Preserve in_flist(fCount-1) LKM018H>  
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End Sub @Tu`0=8