[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： G0]n4"~+?  
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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。 }=GyBnXu  
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背景： )Y *?VqZn  
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。 v"F0$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。 dl":?D4H  
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步骤 M3t_!HP}!  
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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。 nL:vRJr-$  
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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） 93!a  
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 Iiy:<c  
例如下所示： Uv+pdRXn  
Sample name:  EDF-C1-56 k]>k1Mi=  
Merging data from file EDF-C1-56 0-0.txt NqwVsVL  
Finished merging RPC data for sample EDF-C1-56 Q[b({Vj;tG  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt f<}!A$wd  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 +I Ze`M%n  
a. 创建一个新的散射库 fFd9D=EW.  
b. 散射模型命名 ./fEx 'E  
c. 改变散射模型为“Tabulated BSDF”. Qrt8O7&('  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） E%;'3Qykva  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 )Xh_q3=  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， Ov<3?)ok  
g. 点击OK vfbe=)}[  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 `?D_=Gw  
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脚本代码： P5d@-l%}  
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'#Language "WWB-COM" 7YN)T?  
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Option Explicit pS<b|wu?f  
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Sub Main xXx`a\i  
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    'Cleanup hv"toszj\  
    ClearOutputWindow() GY",AL8f  
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    Print "Merging RPC Photonics BSDF Data Files"
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    SetTextColor(255,0,0) jF3!}*7,  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." /SUV'J)  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." &Bp\kv  
    SetTextColor(0,0,0) z^Jl4V  
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    'Current directory of this script (should be the same as the text files being merged) -+9x 0-P  
    Dim cDir As String uv-W/p  
    cDir = MacroDir$ & "\" 4y1>!~f  
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    'Array which will be populated with the list of files to be merged cV{ZDq  
    Dim fList() As String, curFile As String J
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    GetFileList( cDir, fList ) O9|'8"AF  
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    Print "" *QG3Jz
 
    Print "Files found for merging:" NDOZ!`LqH  
    For Each curFile In fList psZeu*/r  
        Print Chr(9) & curFile XsOOkf\_  
    Next )a^Yor)o"  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. X]yERaJ,i  
    Dim nameArray() As String, sampName As String tRy D@}  
    nameArray = Split(fList(0)," 0-0.txt") pq[mM!;#v  
    sampName  = nameArray(0) ZW?7g+P  
    Print "" VRX" @uCD  
    Print "Sample name: " & Chr(9) & sampName t>wxK ,  
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    'Open an output file and write the FRED header data 7idi&h"  
    Dim outFile As String Qsntf.fT  
    outFile = cDir & sampName & "_FRED.txt" }x.)gW  
    Open outFile For Output As #1 VU/W~gb4"A  
    Print #1, "type bsdf_data" O&,O:b:@  
    Print #1, "format angles=deg bsdf=value scale=1" 3\KII9  
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    'Loop the file list, skip the two header lines and write the remaining data to file Su"_1~/2S  
    Dim lineArray() As String, curLine As Long A&P1M6Of  
    For Each curFile In fList lk +K+Ra/  
        Print "Merging data from file " & curFile \ZFQ?e,d  
        ReadFile( cDir & curFile, lineArray ) ` (D4gPW  
        For curLine = 2 To UBound(lineArray) <s-@!8*(  
            Print #1, lineArray(curLine) Nr"N\yOA/  
        Next ]|N4 #4  
    Next X[Ek'=}  

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    'Close the output file 'Y[A'.*}4  
    Close #1 <KwK tgzs  
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    Print "Finished merging RPC data for sample " & sampName tHtV[We.:  
    Print "FRED formatted data file: " & Chr(9) & outFile #Q3PzDfj  
End Sub #tZf>zrs  
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'Utility function to read the contents of a file into an array of strings. $G_Q`w=jM  
Function ReadFile(ByVal fileName As String, _ mY`]33??v  
                  ByRef lineArray() As String) As Long {1MGb%xW  
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    ReadFile = -1 t;!]z-Y>  
    Dim oFSO As Object P!y`$Ky&  
    Set oFSO = CreateObject("Scripting.FileSystemObject") }[z<iij4  
    Erase lineArray 8},<e>q  
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    Dim fid As Long *e<Eu>fW#&  
    If oFSO.fileexists( fileName ) Then HB7(  
        fid = FreeFile() 9>Uq$B  
        Open fileName For Input As fid ChTXvk
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        lineArray = Split(Input(LOF(fid), fid), vbCrLf) lB!vF ~A&  
        Close fid ~"0@u  
    End If h1XMx'}B  
    Set oFSO = Nothing 4C1FPrh  
    Return UBound( lineArray ) GzFE%< 9F  
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End Function :B=8_M  
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Sub GetFileList( ByVal in_dir As String, _ ns#~}2"d  
                 ByRef in_flist() As String ) gKN}Of@^1  
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    'Redimension the file list array u<]m
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    Erase in_flist )_8}53C  
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    'Tracks how many files are found %X9b=%'+  
    Dim fCount As Long 9&%#nN4`8  
    fCount = 0 _(6`{PWY  
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    'Recurse directory and search for text files iS1Gb$?  
    Dim f As String #+"4&:my  
    f = Dir$(in_dir & "*.txt") sz/*w7  
    While f <> "" "#pzZ)Zh  
        ReDim Preserve in_flist(fCount) S= -M3fP~  
        in_flist(fCount) = f -@2'I++"@  
        fCount += 1 t<
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        f = Dir$() SFn 3$ rh  
    Wend tqf&N0*  
    ReDim Preserve in_flist(fCount-1) ,;.B4  
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End Sub 5g``30:o