[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： R43yr+p  
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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。 +8rGStv  
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背景： jmDQKqEc|l  
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。 3Pj 6(cf  
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。 W[dK{?RB  
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步骤 ZW6ZO[`6  
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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。 (4hCT*  
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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） O,&nCxB]  
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 Y"x9B%e  
例如下所示： Z|8oD*,  
Sample name:  EDF-C1-56 wVSk.OOB  
Merging data from file EDF-C1-56 0-0.txt N,iYUM?  
Finished merging RPC data for sample EDF-C1-56 u@;6r"8q  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt .d^XM  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 +zU[rhMk'  
a. 创建一个新的散射库 : J3_g<@  
b. 散射模型命名 P)
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c. 改变散射模型为“Tabulated BSDF”. l(o#N'!j4  
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 ） sS 5aJ}Qs  
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。 G,VTFM6  
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， Qx B0I/ {  
g. 点击OK ?k5m1,fHW  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 IfeCSK,x  
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脚本代码： Rh[%UNl  
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'#Language "WWB-COM" !9B`  
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Option Explicit #- l1(m  
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Sub Main w^_[(9 `  
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    'Cleanup f1hjU~nJ  
    ClearOutputWindow() [&tN(K
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    Print "Merging RPC Photonics BSDF Data Files" aBBTcN%'  
    SetTextColor(255,0,0) TVkC pO,H  
    Print "Note: Script should be located in the same folder as the BSDF TXT files."  Uz;z  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." bJ~@ k,'  
    SetTextColor(0,0,0) _(qU%B  
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    'Current directory of this script (should be the same as the text files being merged) 6X2~30pdE  
    Dim cDir As String 'b?Px}  
    cDir = MacroDir$ & "\" h{J=Rq  
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    'Array which will be populated with the list of files to be merged 0R#T
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    Dim fList() As String, curFile As String c"|4'#S  
    GetFileList( cDir, fList ) ai3wSUYJi  
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    Print "" d0b`qk @4  
    Print "Files found for merging:" Vy-kogVt  
    For Each curFile In fList jm~qD T,  
        Print Chr(9) & curFile uxxS."~  
    Next rZ|!y ~S|  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. l"C)Ia&/  
    Dim nameArray() As String, sampName As String ;Q1/53Y<  
    nameArray = Split(fList(0)," 0-0.txt") A6D@#(D  
    sampName  = nameArray(0) /^m3?q[a  
    Print "" YH:murJMZ  
    Print "Sample name: " & Chr(9) & sampName 'Q^P#<<  
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    'Open an output file and write the FRED header data e>OYJd0s  
    Dim outFile As String _&U5 u  
    outFile = cDir & sampName & "_FRED.txt" g[#4`Q<.  
    Open outFile For Output As #1 fsA
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    Print #1, "type bsdf_data" XOdkfmc+s'  
    Print #1, "format angles=deg bsdf=value scale=1" c`F~vrr)X  
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    'Loop the file list, skip the two header lines and write the remaining data to file ZRK1UpP
 
    Dim lineArray() As String, curLine As Long H.n+CR  
    For Each curFile In fList _#kjiJj*  
        Print "Merging data from file " & curFile MFHc>O DA  
        ReadFile( cDir & curFile, lineArray ) ?HsQ417.H  
        For curLine = 2 To UBound(lineArray) qv+8wJ((  
            Print #1, lineArray(curLine) hj8S".A_  
        Next l6AG!8H  
    Next !%1=|PX_  
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    'Close the output file GC<zL}  
    Close #1 U#7moS'r  
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    Print "Finished merging RPC data for sample " & sampName 3RW3<n  
    Print "FRED formatted data file: " & Chr(9) & outFile :epjJ1mW  
End Sub ftw@nQNU  
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'Utility function to read the contents of a file into an array of strings. x+X^K_*  
Function ReadFile(ByVal fileName As String, _ ",pN.<F9O  
                  ByRef lineArray() As String) As Long `X=2Ff  
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    ReadFile = -1 3hPj;-u  
    Dim oFSO As Object AzfYw'^&9  
    Set oFSO = CreateObject("Scripting.FileSystemObject") $PNS`@B  
    Erase lineArray y5v}EX`m&  
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    Dim fid As Long >_<J=8|E  
    If oFSO.fileexists( fileName ) Then oD0N<Ln}  
        fid = FreeFile() =` %iv|>r0  
        Open fileName For Input As fid f:).wi Ld  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) #Is/j =  
        Close fid ]t23qA@^2  
    End If [^J2<\<0  
    Set oFSO = Nothing 2f=7`1RCD  
    Return UBound( lineArray ) DM73 Nn^5  
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End Function E2 5:eEXa  
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Sub GetFileList( ByVal in_dir As String, _ fFBD5q(n  
                 ByRef in_flist() As String )  =Y0>b4  
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    'Redimension the file list array S]P80|!|  
    Erase in_flist VgoN=S  
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    'Tracks how many files are found 3=SN;cn  
    Dim fCount As Long X`,]@c%C`  
    fCount = 0 x;G~c5  
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    'Recurse directory and search for text files ]Q%|69H}B  
    Dim f As String UB4M=R|  
    f = Dir$(in_dir & "*.txt") T9c=As_EM  
    While f <> "" 9aE.jpN  
        ReDim Preserve in_flist(fCount) LMV0:\>  
        in_flist(fCount) = f t]j4PNzn  
        fCount += 1 WC?}a^
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        f = Dir$() +Yuy%VT  
    Wend |<YoH$.  
    ReDim Preserve in_flist(fCount-1) q*h1=H52  
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End Sub vbZGs7%