[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： M%&`&{  
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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。 ixiRFBUcF~  
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背景： zd#qBj]g  
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。 Fhxg^  
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。 8Mws?]\/q  
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步骤 X:8=jHk
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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。 pPQ]#v  
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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） (nBJ,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 .fo.mC@a  
例如下所示： .vpQ3m>  
Sample name:  EDF-C1-56 B TcxBh  
Merging data from file EDF-C1-56 0-0.txt /^/'9}7  
Finished merging RPC data for sample EDF-C1-56 4D\_[(P  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt *#UDMoz<  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 |C>Yd*E,C  
a. 创建一个新的散射库 0pkU1t~9  
b. 散射模型命名 cO(|>&tJ  
c. 改变散射模型为“Tabulated BSDF”. qViky=/-  
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 ） dqF--)Nb  
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。 )
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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， c$uV8_V  
g. 点击OK &rw|fF|]  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 u{6*}6@fi  
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脚本代码： x(mY$l,il  
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'#Language "WWB-COM" =9pFb!KX  
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Option Explicit Ap}:^k5{  
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Sub Main M
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    'Cleanup d6hWmZVC  
    ClearOutputWindow() !(SaE'  
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    Print "Merging RPC Photonics BSDF Data Files" 3)Paf`mr  
    SetTextColor(255,0,0) ,C=Fgxw(  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." \n<N>j@3  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." {Lq uOC1  
    SetTextColor(0,0,0) h
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    'Current directory of this script (should be the same as the text files being merged) y\x!Be;6Z.  
    Dim cDir As String @9vz%1B<l  
    cDir = MacroDir$ & "\" cp.)K!$  

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    'Array which will be populated with the list of files to be merged _|6{(  
    Dim fList() As String, curFile As String  d(v )SS  
    GetFileList( cDir, fList ) fep#Kb%"e  
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    Print "" b,318R8+G  
    Print "Files found for merging:" 5%4:)s{4|  
    For Each curFile In fList vV=$N"bT~  
        Print Chr(9) & curFile YJ!6)d?C.  
    Next dnNc,l&
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. t[an,3  
    Dim nameArray() As String, sampName As String WgxlQXi-B  
    nameArray = Split(fList(0)," 0-0.txt") F*I{?NRN1  
    sampName  = nameArray(0) `7N[rs9|S  
    Print "" 8Cm^#S,+  
    Print "Sample name: " & Chr(9) & sampName VK?,8Y  
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    'Open an output file and write the FRED header data RqcX_x(p  
    Dim outFile As String @p
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    outFile = cDir & sampName & "_FRED.txt" fMLm_5(H  
    Open outFile For Output As #1 :&TOQ<vM  
    Print #1, "type bsdf_data" Sf*VkH  
    Print #1, "format angles=deg bsdf=value scale=1" @~a52'\  
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    'Loop the file list, skip the two header lines and write the remaining data to file #j;&g1  
    Dim lineArray() As String, curLine As Long < ^J!*>  
    For Each curFile In fList TH6g:YP`7  
        Print "Merging data from file " & curFile t3bDi/m  
        ReadFile( cDir & curFile, lineArray ) ^(&:=r.PC  
        For curLine = 2 To UBound(lineArray) S)Ld^0w  
            Print #1, lineArray(curLine) # <&=ZLN  
        Next M}@^8  
    Next tnKzg21%  
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    'Close the output file Txw,B2e)>  
    Close #1 +o_`k!  

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    Print "Finished merging RPC data for sample " & sampName ,L
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    Print "FRED formatted data file: " & Chr(9) & outFile =ohdL_6  
End Sub Vr5a:u'  
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'Utility function to read the contents of a file into an array of strings. ?rHc%H  
Function ReadFile(ByVal fileName As String, _ !})+WSs'"s  
                  ByRef lineArray() As String) As Long ]HCt%5  
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    ReadFile = -1 x{ZcF=4  
    Dim oFSO As Object  NU_VUd2  
    Set oFSO = CreateObject("Scripting.FileSystemObject") %oN^1a'&)  
    Erase lineArray |/r@z[t  
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    Dim fid As Long 78NAcP~6c  
    If oFSO.fileexists( fileName ) Then QR^pu.k@  
        fid = FreeFile() du47la 3  
        Open fileName For Input As fid v_G4:tY  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) j[Et+V?  
        Close fid eH1Y!&`  
    End If uswz@ [pa  
    Set oFSO = Nothing fxiq
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    Return UBound( lineArray ) }*0%wP  
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End Function &=s{ +0  
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Sub GetFileList( ByVal in_dir As String, _ 4NbC V)Dm  
                 ByRef in_flist() As String ) Y3-15:-  
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    'Redimension the file list array 8@Y@5)Oc  
    Erase in_flist V#sANi?mpo  
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    'Tracks how many files are found zM)o^Fn2  
    Dim fCount As Long 5F0sfX  
    fCount = 0 K
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    'Recurse directory and search for text files _39b8s{  
    Dim f As String 6%fU}si,  
    f = Dir$(in_dir & "*.txt") ,rTR |>Z  
    While f <> "" j[=f;&1  
        ReDim Preserve in_flist(fCount) ql_aDoj  
        in_flist(fCount) = f 
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        fCount += 1 [9$>N  
        f = Dir$() `%rqQnVB  
    Wend Ou,B3kuQ+  
    ReDim Preserve in_flist(fCount-1) 7AtJ6  
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End Sub O0~[]3Y[=