[技术]RPC Photonics扩散片BSDF [复制链接]

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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。 m+<&NDj.  
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背景： 3iCe5VF  
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。 QK]P=pE'C  
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。 ^dI;B27E*  
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步骤 q)?%END  
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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。 k=]e7~!  
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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） &C9IR,&  
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 B\J[O5},
 
例如下所示： Kh]es,$D  
Sample name:  EDF-C1-56 v$y\X3)mB  
Merging data from file EDF-C1-56 0-0.txt @t%da^-HS"  
Finished merging RPC data for sample EDF-C1-56 -9b=-K.y  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt \p4*Q}t  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 6] x6Fe
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a. 创建一个新的散射库 9@*pC@I)  
b. 散射模型命名 f2WVg;Z  
c. 改变散射模型为“Tabulated BSDF”. [V'c
 
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 ） ^E70$yB^  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 yKML{N1D  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， {7:1F)Pj  
g. 点击OK e>MtDJ5  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 Hn/t'D3  
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脚本代码： T|
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'#Language "WWB-COM" k79OMf<v  
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Option Explicit v;(cJ,l  
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Sub Main Zux L2W  
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    'Cleanup 7ys' [G|}r  
    ClearOutputWindow() Ku[q#_7  
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    Print "Merging RPC Photonics BSDF Data Files" fzJiW@-T  
    SetTextColor(255,0,0) H:G``Vq;0m  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." 1I2ndt  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." LQF;T7VKS)  
    SetTextColor(0,0,0) MV5$e  
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    'Current directory of this script (should be the same as the text files being merged) J_)F/S!T  
    Dim cDir As String 4 $k{,  
    cDir = MacroDir$ & "\" upMs yLp(  
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    'Array which will be populated with the list of files to be merged !!.@F;]W  
    Dim fList() As String, curFile As String \;XJ$~>  
    GetFileList( cDir, fList ) w"v96%"Y  
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    Print "" YIN* '!N  
    Print "Files found for merging:" |;J`~H"K  
    For Each curFile In fList nk!uO^  
        Print Chr(9) & curFile / B!j`UK  
    Next Ox)<"8M  

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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. v}!lx)#  
    Dim nameArray() As String, sampName As String =sWK;`  
    nameArray = Split(fList(0)," 0-0.txt") Ea4zC|;  
    sampName  = nameArray(0) CV[9i  
    Print "" gPn0-)<  
    Print "Sample name: " & Chr(9) & sampName ftn10TO*  
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    'Open an output file and write the FRED header data W(62.3d~}?  
    Dim outFile As String l9QIlTc7  
    outFile = cDir & sampName & "_FRED.txt" ",~ZO<P  
    Open outFile For Output As #1 LDegJer-v  
    Print #1, "type bsdf_data" H0b{`!'Fs:  
    Print #1, "format angles=deg bsdf=value scale=1" U2`:'  
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    'Loop the file list, skip the two header lines and write the remaining data to file m2m ;|rr  
    Dim lineArray() As String, curLine As Long hGKQK ^bn  
    For Each curFile In fList @CM5e!  
        Print "Merging data from file " & curFile rX^uHq8  
        ReadFile( cDir & curFile, lineArray ) ]HWeVhG  
        For curLine = 2 To UBound(lineArray) p63fpnH  
            Print #1, lineArray(curLine) $JOtUB{  
        Next {JdXn  
    Next $$$[Vn_H<  
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    'Close the output file |

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    Close #1 `j{q  
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    Print "Finished merging RPC data for sample " & sampName # ,H!<X;SS  
    Print "FRED formatted data file: " & Chr(9) & outFile _k}Qe;  
End Sub _rSwQ<38>  
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'Utility function to read the contents of a file into an array of strings. 7Tp+]"bL  
Function ReadFile(ByVal fileName As String, _ n+ H2cl }  
                  ByRef lineArray() As String) As Long U `lp56  
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    ReadFile = -1 VOYQ<tg  
    Dim oFSO As Object %4R1rUrgt|  
    Set oFSO = CreateObject("Scripting.FileSystemObject") i\uj>;B  
    Erase lineArray V}`ri~  
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    Dim fid As Long ~zZOogM<  
    If oFSO.fileexists( fileName ) Then NVQ.;"2w  
        fid = FreeFile() tW!*W?  
        Open fileName For Input As fid Ze/\IBd  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) le_aIbB"P  
        Close fid 83]m/
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    End If hKg +A  
    Set oFSO = Nothing cD9U^SOS  
    Return UBound( lineArray ) e2fv%  
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End Function d %FLk=]  
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Sub GetFileList( ByVal in_dir As String, _ +P9eE,WR  
                 ByRef in_flist() As String ) *"OlO}o  
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    'Redimension the file list array eU)QoVt  
    Erase in_flist JPL`/WA0  
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    'Tracks how many files are found )zy;!  
    Dim fCount As Long Xhyn! &H5  
    fCount = 0 #%%!r$UL  
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    'Recurse directory and search for text files *qYw  
    Dim f As String FbMtor  
    f = Dir$(in_dir & "*.txt") ]Ar,HaX-  
    While f <> "" Xe:rPxZf~  
        ReDim Preserve in_flist(fCount) b)
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        in_flist(fCount) = f I5QtPqB>  
        fCount += 1 T#6g5Jnsp  
        f = Dir$() E`xpZ>$mPx  
    Wend T12Zak4.=  
    ReDim Preserve in_flist(fCount-1) SXe1Q8;  
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End Sub m8 _yorz