[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： (=/F=,w   
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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。 =c,gK8C  
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背景： 2T5xSpC  
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。 $"8k|^Z3  
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。 `Z/IW  
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步骤 %p9bl ,x  
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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。 <J)A_Kx[57  
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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） *r`Yz}  
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 -T?IkL)  
例如下所示： !Ia"pNDf  
Sample name:  EDF-C1-56 pPZ/O6  
Merging data from file EDF-C1-56 0-0.txt j''Iai_  
Finished merging RPC data for sample EDF-C1-56 i .N1Cvp&  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt #%9]Lq  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面  YBD{l  
a. 创建一个新的散射库 lX*;KHT)  
b. 散射模型命名 m GhJn  
c. 改变散射模型为“Tabulated BSDF”. tFaE cP  
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 ） qN[7zsaj  
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。 :\U3bkv+  
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， Hg`{9v  
g. 点击OK `#rfp 9w  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 (U_Q7hja?  
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脚本代码： Z0eB
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'#Language "WWB-COM" ik*)j  
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Option Explicit wYA/<0'yH  
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Sub Main (AG  
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    'Cleanup qffSq](D.  
    ClearOutputWindow() %vtSeJ  
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    Print "Merging RPC Photonics BSDF Data Files" k|3(dXLG  
    SetTextColor(255,0,0) 1=Zw=ufqV  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." I#X2UQzP  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." 6KCmswvE  
    SetTextColor(0,0,0) b8Rh|"J)
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    'Current directory of this script (should be the same as the text files being merged)
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    Dim cDir As String 0@K:Tq-mF  
    cDir = MacroDir$ & "\" [4Faq3T"  
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    'Array which will be populated with the list of files to be merged L4pjh&+8  
    Dim fList() As String, curFile As String 
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    GetFileList( cDir, fList ) OawrS{  
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    Print "" ;Uqx&5P}  
    Print "Files found for merging:" 'e>sHL  
    For Each curFile In fList DRW.NL o  
        Print Chr(9) & curFile 1Bk*G>CX9(  
    Next 5o| !f  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement.
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    Dim nameArray() As String, sampName As String 4A/,X>W61  
    nameArray = Split(fList(0)," 0-0.txt") 2^bpH%  
    sampName  = nameArray(0) NhK(HTsvK  
    Print "" 3y=<w|4F  
    Print "Sample name: " & Chr(9) & sampName Q^Z<RA(C  
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    'Open an output file and write the FRED header data >3`ctbe  
    Dim outFile As String |5IY`;+9  
    outFile = cDir & sampName & "_FRED.txt" gQh Ccv  
    Open outFile For Output As #1 sIRrEea  
    Print #1, "type bsdf_data" :.S41S   
    Print #1, "format angles=deg bsdf=value scale=1" HS`bto0*  
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    'Loop the file list, skip the two header lines and write the remaining data to file #1't"R+3M  
    Dim lineArray() As String, curLine As Long ;2Ad])  
    For Each curFile In fList ah/6;,T  
        Print "Merging data from file " & curFile 380->  
        ReadFile( cDir & curFile, lineArray ) dI0
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        For curLine = 2 To UBound(lineArray) Ef`5fgp? S  
            Print #1, lineArray(curLine) ]tQDk4&i  
        Next R'9@A\7#  
    Next ^[seK)S=  
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    'Close the output file v!#`W  
    Close #1 aC,vh1")F  
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    Print "Finished merging RPC data for sample " & sampName T]nR=uK6LL  
    Print "FRED formatted data file: " & Chr(9) & outFile `F2*o47|t  
End Sub f1Yv hvWL  
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'Utility function to read the contents of a file into an array of strings. <Id1:  
Function ReadFile(ByVal fileName As String, _ g2aT`=&Z  
                  ByRef lineArray() As String) As Long fa4951_  
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    ReadFile = -1 8XYD L]I'  
    Dim oFSO As Object 4VmCW"b7h  
    Set oFSO = CreateObject("Scripting.FileSystemObject") xV,4U/T  
    Erase lineArray _PyW=Tj  
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    Dim fid As Long Pv7f _hw  
    If oFSO.fileexists( fileName ) Then 8)W?la8'p  
        fid = FreeFile() oBRm\8 2|  
        Open fileName For Input As fid P^b:?%  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) TRk ?8  
        Close fid Krp <bK6  
    End If 6`DwEs?Y{  
    Set oFSO = Nothing 'z +$3\5L  
    Return UBound( lineArray ) lTV@b&  
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End Function uv|eVT3jNs  
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Sub GetFileList( ByVal in_dir As String, _ 0+K`pS'  
                 ByRef in_flist() As String ) N?a1sdR  
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    'Redimension the file list array ;!l*7}5X=  
    Erase in_flist 'ZGT`'ri  
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    'Tracks how many files are found a%Z4_ToLZ  
    Dim fCount As Long `W"a!,s2  
    fCount = 0 Vq3]7l  
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    'Recurse directory and search for text files 7m|`tjQ1  
    Dim f As String %w'/n>]j  
    f = Dir$(in_dir & "*.txt") MtpU~c  
    While f <> "" VM-qVd-  
        ReDim Preserve in_flist(fCount) 'A@q
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        in_flist(fCount) = f A~6%,q@^jh  
        fCount += 1 cy=I0  
        f = Dir$() pBSq%Hy:  
    Wend saGRP}7?  
    ReDim Preserve in_flist(fCount-1) aW0u8Dz  
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End Sub o,S!RG&