[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： -|?I'~[#(  
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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。 AI$r^t1  
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背景： E@/yg(?d=  
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。 }`O_  
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。 (BB&ZUdyv  
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步骤 h)W?8
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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。 <Ae1YHUY  
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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） 9]ga\>v  
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 ewo
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例如下所示： 1eg/<4]hA  
Sample name:  EDF-C1-56 JGJXV
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Merging data from file EDF-C1-56 0-0.txt W[5a'}OV  
Finished merging RPC data for sample EDF-C1-56 ;1S~'B&1Q  
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 $ BEIG@qG  
a. 创建一个新的散射库 F,t ,Ja  
b. 散射模型命名 )1PZ#  
c. 改变散射模型为“Tabulated BSDF”. sH//*y
  
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 ） l!U_7)s/  
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。 2wHvHH!  
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， SJYy,F],V"  
g. 点击OK o\_@4hXf  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 [k"@n+%  
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脚本代码： Jj<UtD+  
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'#Language "WWB-COM" =}:9y6QR.  
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Option Explicit ~Rs_ep'+Q2  
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Sub Main mSn>  
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    'Cleanup $1QQidB  
    ClearOutputWindow() Z9:erKT   
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    Print "Merging RPC Photonics BSDF Data Files" n*tT<  
    SetTextColor(255,0,0) CM}1:o<
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    Print "Note: Script should be located in the same folder as the BSDF TXT files." bB|UQaCl  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." ~!*xi  
    SetTextColor(0,0,0) =")}wl=s  
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    'Current directory of this script (should be the same as the text files being merged) +-~:E_G  
    Dim cDir As String  E*[dc  
    cDir = MacroDir$ & "\" `yjHLg  
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    'Array which will be populated with the list of files to be merged k4|9'V&1*6  
    Dim fList() As String, curFile As String |5uvmK  
    GetFileList( cDir, fList ) 5r=xhOe`  
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    Print "" ~9&#7fU  
    Print "Files found for merging:" \a:#e%]qz9  
    For Each curFile In fList Y\7>>?  
        Print Chr(9) & curFile R3nCk-Dq  
    Next H4s^&--  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. 'z=WJV;Vs  
    Dim nameArray() As String, sampName As String hdL/zW7]  
    nameArray = Split(fList(0)," 0-0.txt") Yp_ L.TTb  
    sampName  = nameArray(0) R,mOV8y"W[  
    Print "" RlRkw+%m  
    Print "Sample name: " & Chr(9) & sampName up[9L|  
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    'Open an output file and write the FRED header data Kjw4,z%\94  
    Dim outFile As String X<\E 'v`~  
    outFile = cDir & sampName & "_FRED.txt" \Tf$i(0q  
    Open outFile For Output As #1 pmm?Fq!s=  
    Print #1, "type bsdf_data" :%[=v(G[  
    Print #1, "format angles=deg bsdf=value scale=1" iV h^;  
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    'Loop the file list, skip the two header lines and write the remaining data to file ~r<@`[-L  
    Dim lineArray() As String, curLine As Long cL31g_u  
    For Each curFile In fList wul$lJ?tE  
        Print "Merging data from file " & curFile n#jBqr&!M  
        ReadFile( cDir & curFile, lineArray ) 3\x
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        For curLine = 2 To UBound(lineArray) [E9V#J89  
            Print #1, lineArray(curLine) ?gknJ:  
        Next qPh @Bl3  
    Next ^*CvKCS  
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    'Close the output file b2}>{L
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    Close #1 3V)ef$Y0  
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    Print "Finished merging RPC data for sample " & sampName r5

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    Print "FRED formatted data file: " & Chr(9) & outFile P
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End Sub !Zowe*`
 
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'Utility function to read the contents of a file into an array of strings. M^q< qS>d  
Function ReadFile(ByVal fileName As String, _ !+sC'/  
                  ByRef lineArray() As String) As Long LAe>XF-5  
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    ReadFile = -1 _n6ge*,E  
    Dim oFSO As Object glMYEGz6p  
    Set oFSO = CreateObject("Scripting.FileSystemObject") U GA_^?4  
    Erase lineArray L1'PQV  
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    Dim fid As Long o1Bn^w  
    If oFSO.fileexists( fileName ) Then ?q^o|Y/  
        fid = FreeFile() L<t>o":o  
        Open fileName For Input As fid 1D*oXE9Ig  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) hv)>HU
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        Close fid &cZQ,o  
    End If C%2BDj  
    Set oFSO = Nothing kJQH{n+)R  
    Return UBound( lineArray ) #&V7CYJ  
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End Function 7a$K@iWU  
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Sub GetFileList( ByVal in_dir As String, _ YmrrZ&]q  
                 ByRef in_flist() As String ) v|!u]!JM  
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    'Redimension the file list array 5j8aMnvs  
    Erase in_flist (p19"p  
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    'Tracks how many files are found Lud[.>i  
    Dim fCount As Long mu#IF'|b  
    fCount = 0 1X8P v*,  
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    'Recurse directory and search for text files OC?a[^hB^)  
    Dim f As String +9^V9]{Vo  
    f = Dir$(in_dir & "*.txt") Z\lJE>1  
    While f <> "" _GhP{C$  
        ReDim Preserve in_flist(fCount) ~Q+E""  
        in_flist(fCount) = f 0W_olnZ  
        fCount += 1 6TR` O  
        f = Dir$() CF,-l B  
    Wend r\PO?1  
    ReDim Preserve in_flist(fCount-1) (DLk+N4UHA  
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End Sub n-"(lWcp