[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： UP*yeT,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。 p1?J  
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背景： ~,+[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。 5W5pRd>Q  
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。 J\GKqt;5@  
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步骤 6(sfpK'  
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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。 cnYYs d{  
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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） ls]Elo8h1f  
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
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例如下所示： 9XY|V<}  
Sample name:  EDF-C1-56 [L)V(o)v  
Merging data from file EDF-C1-56 0-0.txt GZ.?MnG  
Finished merging RPC data for sample EDF-C1-56 25w6KBTe;:  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt k0=|10bi  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 eb(m8vLR  
a. 创建一个新的散射库 )/ n29]  
b. 散射模型命名 739l%u }<  
c. 改变散射模型为“Tabulated BSDF”. =b|)Wnt2f  
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 ） >02i8:Tp5K  
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。 [lrmuf  
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， RNl\`>Cz  
g. 点击OK _4!7 zW^  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 &<#/&Pq/i  
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脚本代码： ` 3vN R"  
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'#Language "WWB-COM" J>/Ci\OB  
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Option Explicit )moo?Q  
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Sub Main ~4}*D
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    'Cleanup lu<Np9/5<  
    ClearOutputWindow() gE-lM/w  
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    Print "Merging RPC Photonics BSDF Data Files" (4E.Li<O  
    SetTextColor(255,0,0) s=3EBh  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." B6^w{eXN  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." R4[. n@  
    SetTextColor(0,0,0) q^Q|.&_k /  
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    'Current directory of this script (should be the same as the text files being merged) cob9hj#&7  
    Dim cDir As String Z5{*? 2  
    cDir = MacroDir$ & "\" fbi H   
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    'Array which will be populated with the list of files to be merged O1l4gduN|i  
    Dim fList() As String, curFile As String ,dGFX]P  
    GetFileList( cDir, fList ) l;"ub^AH  

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    Print "" k4]R]=Fh.  
    Print "Files found for merging:" ksxO<Y  
    For Each curFile In fList w}]3jc84  
        Print Chr(9) & curFile ZA 99vO  
    Next e2,<,~_K6  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. ft*G*.0kO  
    Dim nameArray() As String, sampName As String #khyy-B=  
    nameArray = Split(fList(0)," 0-0.txt") 6i*p +S?U"  
    sampName  = nameArray(0) x`/m>~_  
    Print "" ,.1&Ff
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    Print "Sample name: " & Chr(9) & sampName 9;m#>a@Y  
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    'Open an output file and write the FRED header data Bh.6:9{  
    Dim outFile As String >@q2FSMf  
    outFile = cDir & sampName & "_FRED.txt" kM6 EZ`mj  
    Open outFile For Output As #1 H>@JfYZ0  
    Print #1, "type bsdf_data" a78;\{&L'  
    Print #1, "format angles=deg bsdf=value scale=1" n57c^/A*  
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    'Loop the file list, skip the two header lines and write the remaining data to file ~7eUt^SD;  
    Dim lineArray() As String, curLine As Long 'Sb6 w+  
    For Each curFile In fList CU} q&6h  
        Print "Merging data from file " & curFile 6+{nw}e8  
        ReadFile( cDir & curFile, lineArray ) &B{Jxc`VA  
        For curLine = 2 To UBound(lineArray) sf|_2sI  
            Print #1, lineArray(curLine) &~D.")Dz  
        Next oeRYyJ  
    Next mt&JgA/  
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    'Close the output file 0t/z"  
    Close #1 HY%6eUhj  
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    Print "Finished merging RPC data for sample " & sampName 2t Z\{=  
    Print "FRED formatted data file: " & Chr(9) & outFile  9\W5
 
End Sub &].1[&M]  
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'Utility function to read the contents of a file into an array of strings. t9=|* =;9)  
Function ReadFile(ByVal fileName As String, _ q>Ar.5&M_  
                  ByRef lineArray() As String) As Long d/-0B<ts  
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    ReadFile = -1 h&^/, G  
    Dim oFSO As Object N5I W@?4  
    Set oFSO = CreateObject("Scripting.FileSystemObject") 3GuMiht5  
    Erase lineArray S+bWD7  
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    Dim fid As Long VS@rM<K{  
    If oFSO.fileexists( fileName ) Then ^ZViQ$a"h;  
        fid = FreeFile() Q& unA3  
        Open fileName For Input As fid J{'zkR?Lr  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) /F  
        Close fid E6KBpQcd[
 
    End If i}
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    Set oFSO = Nothing ]jT[dX|?  
    Return UBound( lineArray ) |^&2zyUj/  
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End Function /hj9Q!  
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Sub GetFileList( ByVal in_dir As String, _ 'E6gEJ  
                 ByRef in_flist() As String ) myo~Qqt?  
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    'Redimension the file list array 1k70>RQ&69  
    Erase in_flist Dg2#Gv0B  
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    'Tracks how many files are found pU)3*9?cIl  
    Dim fCount As Long {/VL\AW5$  
    fCount = 0 yl]Cm?8  
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    'Recurse directory and search for text files ]NhWhJ:  
    Dim f As String Nv$gKC6 ,G  
    f = Dir$(in_dir & "*.txt") U\!LZ?gC  
    While f <> "" ~a0}  
        ReDim Preserve in_flist(fCount) ]Pl6:FB8%@  
        in_flist(fCount) = f ,Z\,IRn  
        fCount += 1 *V<2\-  
        f = Dir$() 5'L}LT8p@  
    Wend 2|H'j~  
    ReDim Preserve in_flist(fCount-1) kQi
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End Sub /01(9(