[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： h<3bv&oI .  
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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。 -0a3eg)Z*  
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背景： >#dLT~[\a  
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。 ~~Cd9Hzi  
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。 1f3g5y'z5  
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步骤
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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。 >l}v _k*~B  
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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） }#Up:o]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 E5gt_,j>  
例如下所示： B$c'^ )  
Sample name:  EDF-C1-56 L?N:4/0;!  
Merging data from file EDF-C1-56 0-0.txt bPV}T`  
Finished merging RPC data for sample EDF-C1-56 Dg^s$2  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt zKk=R6w  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 x15&U\U  
a. 创建一个新的散射库 Nba1!5:M  
b. 散射模型命名 0dx%b677d  
c. 改变散射模型为“Tabulated BSDF”.  pb<eg,  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） Ku6ndc  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 O 8l`1  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， y2g)*T!m  
g. 点击OK o7tlkSZ  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 _ y'g11 \  
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脚本代码： =H-BsX?P  
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'#Language "WWB-COM" ?/3{gOgI$`  
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Option Explicit 9~ V
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Sub Main =f=>buD  
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    'Cleanup `)=sQ2P  
    ClearOutputWindow() QeQwmI  
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    Print "Merging RPC Photonics BSDF Data Files" cor!Sa>  
    SetTextColor(255,0,0)  (=%0x"'  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." G #$r)S  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." 4fL>Ou[YuX  
    SetTextColor(0,0,0) ckdCd J  
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    'Current directory of this script (should be the same as the text files being merged) @ uL4'@Ej  
    Dim cDir As String wVv@   
    cDir = MacroDir$ & "\" fn//j7 j  
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    'Array which will be populated with the list of files to be merged ;k1VY I
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    Dim fList() As String, curFile As String \!)1n[N  
    GetFileList( cDir, fList ) W1}d6Sbg  
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    Print "" 0VgsV;  
    Print "Files found for merging:" od/Q"5t[p  
    For Each curFile In fList )"bP]t^_  
        Print Chr(9) & curFile 9Kc;]2
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    Next DRu#vC  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. r[nvgzv@  
    Dim nameArray() As String, sampName As String ];{CNDAL2  
    nameArray = Split(fList(0)," 0-0.txt") "V4ru&a  
    sampName  = nameArray(0) y $>U[^G[  
    Print "" UDgUbi^v|D  
    Print "Sample name: " & Chr(9) & sampName @ojV8  
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    'Open an output file and write the FRED header data <QRRD*\  
    Dim outFile As String Z&Z=24q_  
    outFile = cDir & sampName & "_FRED.txt" WD'[|s\  
    Open outFile For Output As #1 Cbr>\;sc2Z  
    Print #1, "type bsdf_data" UNescZ  
    Print #1, "format angles=deg bsdf=value scale=1" $s9YU"  
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    'Loop the file list, skip the two header lines and write the remaining data to file idP2G|Z  
    Dim lineArray() As String, curLine As Long oAq<ag\qV  
    For Each curFile In fList G+W0X  
        Print "Merging data from file " & curFile y[~w2a&+  
        ReadFile( cDir & curFile, lineArray ) _*dUH5  
        For curLine = 2 To UBound(lineArray) r=^?  
            Print #1, lineArray(curLine) hT$/B|  
        Next N:e5=;6s  
    Next 6nHyd<o  
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    'Close the output file NR0fxh  
    Close #1 ]w9\q*S]  
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    Print "Finished merging RPC data for sample " & sampName M@78.lPS  
    Print "FRED formatted data file: " & Chr(9) & outFile QMWDII&t  
End Sub 0%GQXiy  
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'Utility function to read the contents of a file into an array of strings. &0%x6vea  
Function ReadFile(ByVal fileName As String, _ 4
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                  ByRef lineArray() As String) As Long 2:Q2w3Xe  
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    ReadFile = -1 +OX:T) 4h6  
    Dim oFSO As Object ;UDd4@3`S"  
    Set oFSO = CreateObject("Scripting.FileSystemObject") u(g0Ob  
    Erase lineArray Zdll}n
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    Dim fid As Long QwgP+ M+  
    If oFSO.fileexists( fileName ) Then n0%]dKCB  
        fid = FreeFile() gOKF%Ej31T  
        Open fileName For Input As fid )l"py9
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        lineArray = Split(Input(LOF(fid), fid), vbCrLf) X) xeq  
        Close fid NE2P "mY  
    End If 7xy[;  
    Set oFSO = Nothing
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    Return UBound( lineArray ) ]Geg;[t  
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End Function k_hs g6Ur.  
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Sub GetFileList( ByVal in_dir As String, _ U%E364;F  
                 ByRef in_flist() As String ) YVS~|4hu?i  
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    'Redimension the file list array QO(P_az3mg  
    Erase in_flist }D\i1/Y  
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    'Tracks how many files are found y ZR\(\?<  
    Dim fCount As Long d\A!5/LG  
    fCount = 0 nH7i)!cI~  
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    'Recurse directory and search for text files s2ixiv=  
    Dim f As String Cqc5jx0)  
    f = Dir$(in_dir & "*.txt") \zGmZZ  
    While f <> "" i"J`$u  
        ReDim Preserve in_flist(fCount) Hklgf  
        in_flist(fCount) = f b'$fr6"O1  
        fCount += 1 8|Vm6*TY&p  
        f = Dir$() ~Ddlr9Ej  
    Wend #Z>EX?VS:  
    ReDim Preserve in_flist(fCount-1) o/5loV3h  
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End Sub c#YW>(