[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： S#F%OIx  
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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。 9!,f4&G`  
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背景： v@1f,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。 e% #?B *  
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。 "3$P<Q\;l;  
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步骤 [N_)V kpr  
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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。 r:Ok z  
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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） C[[:/X(c  
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 z]R% A:6K  
例如下所示： mc|8t0+1`  
Sample name:  EDF-C1-56 om1D}irKT  
Merging data from file EDF-C1-56 0-0.txt ~kOXMLRg  
Finished merging RPC data for sample EDF-C1-56 t&MLgu  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt F @uOXNz)  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 .GiQC{@9w  
a. 创建一个新的散射库 |6w{%xC?"  
b. 散射模型命名 '^`%  
c. 改变散射模型为“Tabulated BSDF”. yhxZ^(I  
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 ） _53NuEM1  
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。 y:VY8a 4
 
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， ^o[(F<q  
g. 点击OK ?Vc/mO2X  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 '&F PkT:5  
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脚本代码：
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'#Language "WWB-COM" nzl3<Ar  
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Option Explicit t}2M8ue(&  
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Sub Main Ta)6
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    'Cleanup wiM-TFT~  
    ClearOutputWindow() N3|aNQ=X0  
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    Print "Merging RPC Photonics BSDF Data Files" ZWy,NN1  
    SetTextColor(255,0,0) 4@"n7/<  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." ke5_lr(  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." l/6(V:  
    SetTextColor(0,0,0) Z]k+dJ[-  
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    'Current directory of this script (should be the same as the text files being merged) cE3V0voSw1  
    Dim cDir As String 3NlG,e'T2  
    cDir = MacroDir$ & "\" E)%r}4u>  
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    'Array which will be populated with the list of files to be merged c\N-B,m&  
    Dim fList() As String, curFile As String OIrr'uNH  
    GetFileList( cDir, fList )  2D"\Ox  
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    Print "" ^ZG 3{>  
    Print "Files found for merging:" !K/
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    For Each curFile In fList <'92\O  
        Print Chr(9) & curFile c7/fQc)h4d  
    Next jWerX -$  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. W*Ce1  
    Dim nameArray() As String, sampName As String Y%YPR=j~ &  
    nameArray = Split(fList(0)," 0-0.txt") RiCzH  
    sampName  = nameArray(0) XFcIBWS  
    Print "" E@S5|CM  
    Print "Sample name: " & Chr(9) & sampName :~B'6b  
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    'Open an output file and write the FRED header data !_LRuqQ?"  
    Dim outFile As String GoRSLbCUR  
    outFile = cDir & sampName & "_FRED.txt" =RQ\i6Y  
    Open outFile For Output As #1 I cz)Qtg|  
    Print #1, "type bsdf_data" \&1Di\eL  
    Print #1, "format angles=deg bsdf=value scale=1" 7Hp~:i30  
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    'Loop the file list, skip the two header lines and write the remaining data to file #>(h!lT_  
    Dim lineArray() As String, curLine As Long t?cO>4*|  
    For Each curFile In fList 2F fwct:  
        Print "Merging data from file " & curFile 2ZZF hj  
        ReadFile( cDir & curFile, lineArray ) 4I<U5@a  
        For curLine = 2 To UBound(lineArray) '3V?M;3|K  
            Print #1, lineArray(curLine) 7EukrE<b'  
        Next Jz'8|o;^  
    Next {;Ispx0m  
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    'Close the output file D"+xF&  
    Close #1 'UL"yM  
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    Print "Finished merging RPC data for sample " & sampName z\Y-8a.]  
    Print "FRED formatted data file: " & Chr(9) & outFile SPU_@ Pk  
End Sub O)WduhlGQ  
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'Utility function to read the contents of a file into an array of strings. x1nqhSaD  
Function ReadFile(ByVal fileName As String, _ C`>|D [  
                  ByRef lineArray() As String) As Long vW:XM0  
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    ReadFile = -1 4'ymPPY  
    Dim oFSO As Object iPoDesp  
    Set oFSO = CreateObject("Scripting.FileSystemObject") *Mr?}_,X*  
    Erase lineArray ,6FmU$ Kn  
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    Dim fid As Long ??.9`3CYo  
    If oFSO.fileexists( fileName ) Then Ib665H7w  
        fid = FreeFile() `VxfAV?}  
        Open fileName For Input As fid h(VF  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) FD*w4U5  
        Close fid |6}:n,KA.  
    End If $Q!J.}P@  
    Set oFSO = Nothing fooQqWC)  
    Return UBound( lineArray ) zIjUfgO/M  
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End Function V`MV_zA2  
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Sub GetFileList( ByVal in_dir As String, _ 'WW['  
                 ByRef in_flist() As String ) @hE$x-TP0  
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    'Redimension the file list array b#<@&0KE  
    Erase in_flist <BNCo5*  
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    'Tracks how many files are found KoPhPH  
    Dim fCount As Long M)oJ06`K  
    fCount = 0 !@<>S>uGG  
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    'Recurse directory and search for text files VD*xhuy$k  
    Dim f As String e~,/Z\i  
    f = Dir$(in_dir & "*.txt") N7`<t&T@  
    While f <> "" j4B|ktf  
        ReDim Preserve in_flist(fCount) xe
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        in_flist(fCount) = f wEImpsC`  
        fCount += 1 _+\hDV>v  
        f = Dir$() 1li1&  
    Wend D>c-h)2|
 
    ReDim Preserve in_flist(fCount-1) %)K)h&m  
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End Sub mfNYN4Um6