[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： D!D%.  
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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?R+Z6c[  
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背景： t&Y^W <  
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。 enD 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。 zk^7gx3x  
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步骤 hoD[wAC  
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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。 @l6dJ  
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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） @1qUC"Mg  
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 $gD(MKR)~  
例如下所示： [#@p{[?r  
Sample name:  EDF-C1-56  d7-F&!sQ  
Merging data from file EDF-C1-56 0-0.txt xzf)_ <  
Finished merging RPC data for sample EDF-C1-56 { G>+.  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt "F.J>QBd  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 5bqYi  
a. 创建一个新的散射库 ewff(e9  
b. 散射模型命名 CYic_rF$  
c. 改变散射模型为“Tabulated BSDF”. pcxl2I  
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 ） O [ ;6E  
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。 >,Swk3  
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 _,$`nEJ  
g. 点击OK ABYW1K=  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 N@`9 ~JS  
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脚本代码： bA9
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'#Language "WWB-COM" =VI`CBQ/Um  
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Option Explicit %KVRiX  

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Sub Main @md^
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    'Cleanup _f2iz4  
    ClearOutputWindow() o>k-~v7  
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    Print "Merging RPC Photonics BSDF Data Files" A
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    SetTextColor(255,0,0) <qj@waKw4  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." n#AH@`&i  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." Vblf6qaBs  
    SetTextColor(0,0,0) |P?B AWYeQ  
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    'Current directory of this script (should be the same as the text files being merged) B!C32~[  
    Dim cDir As String p.7p,CyB  
    cDir = MacroDir$ & "\" oM7-1O  
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    'Array which will be populated with the list of files to be merged -Y,Ibq  
    Dim fList() As String, curFile As String  [ ^ \)  
    GetFileList( cDir, fList ) +?eAaC7s  
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    Print "" :z5Ibas:  
    Print "Files found for merging:" 
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    For Each curFile In fList n7<-lQRaxZ  
        Print Chr(9) & curFile O*"wQ50Ou  
    Next AyXKhj#Ml  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. .:Xe*Q  
    Dim nameArray() As String, sampName As String uPD_s[  
    nameArray = Split(fList(0)," 0-0.txt") VFp)`+8  
    sampName  = nameArray(0) S^_yiV S  
    Print "" lt2&uYgp  
    Print "Sample name: " & Chr(9) & sampName f*f9:xUY  
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    'Open an output file and write the FRED header data ~$9"|  
    Dim outFile As String b<MMli  
    outFile = cDir & sampName & "_FRED.txt" ,=yIfbFQ  
    Open outFile For Output As #1 J\},o|WI  
    Print #1, "type bsdf_data" (.t:sn"P  
    Print #1, "format angles=deg bsdf=value scale=1" {-Oc8XI/  
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    'Loop the file list, skip the two header lines and write the remaining data to file *J-jr8&  
    Dim lineArray() As String, curLine As Long BU .G~0  
    For Each curFile In fList o{,(`o.1O  
        Print "Merging data from file " & curFile PltPIu)F  
        ReadFile( cDir & curFile, lineArray ) dNmX<WXG  
        For curLine = 2 To UBound(lineArray) 6iS+3+  
            Print #1, lineArray(curLine) x?$Y<=vT  
        Next g4932_tC  
    Next m=y)i]=1  
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    'Close the output file z>q_]U0  
    Close #1 pfIvBU?  
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    Print "Finished merging RPC data for sample " & sampName s7gf7E#Y  
    Print "FRED formatted data file: " & Chr(9) & outFile !T1i_  
End Sub @uWD>(D  
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'Utility function to read the contents of a file into an array of strings. 0 N^V&k   
Function ReadFile(ByVal fileName As String, _ }e6:&`a xD  
                  ByRef lineArray() As String) As Long /qY(uPJ  
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    ReadFile = -1 Sa(rl^qZ2  
    Dim oFSO As Object qd;f]ndo  
    Set oFSO = CreateObject("Scripting.FileSystemObject") 9]9(o  
    Erase lineArray |8rJqtf +&  
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    Dim fid As Long "R]K!GUU  
    If oFSO.fileexists( fileName ) Then cZ,_O~  
        fid = FreeFile() auv\fR :  
        Open fileName For Input As fid 6ns_4, e  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) sRG3`>1  
        Close fid e$h\7i:(  
    End If 43fA;Uc{Y`  
    Set oFSO = Nothing [!$>:_Vq/  
    Return UBound( lineArray ) :@L5=2Z+  
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End Function w, wt<@}  
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Sub GetFileList( ByVal in_dir As String, _ &ICO{#v5  
                 ByRef in_flist() As String ) F3'G9Xf8Q=  
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    'Redimension the file list array x]M1UBnMN  
    Erase in_flist %stktVDAP  
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    'Tracks how many files are found K!mgh7Dx  
    Dim fCount As Long oE&[W>,x  
    fCount = 0 q fe#kF9  
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    'Recurse directory and search for text files `VbG%y&I  
    Dim f As String 19DW~kvYk  
    f = Dir$(in_dir & "*.txt") : Dlk`?  
    While f <> "" <k1gc
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        ReDim Preserve in_flist(fCount) >oNs_{  
        in_flist(fCount) = f )}v2Z3:  
        fCount += 1 o%iTYR:x  
        f = Dir$() }#M|3h;q9+  
    Wend wz=I+IN:  
    ReDim Preserve in_flist(fCount-1) ySZ)yT  
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End Sub [d}1Cq=_