[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： imc1rY!~'  
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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。 ]xxE_B7  
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背景： Og-v][  
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。 GLp~SeF#  
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。 sa?s[  
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步骤 qm/#kPlM  
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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。 PO nF_FC  
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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） zI= 9  
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 Q_6v3no1  
例如下所示： 7Hg;SK6t0  
Sample name:  EDF-C1-56 OUhlQq\  
Merging data from file EDF-C1-56 0-0.txt GYrUB59  
Finished merging RPC data for sample EDF-C1-56 5cj&D74o  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt LEg ?/!LIT  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 *X!+wK-+  
a. 创建一个新的散射库 6!@p$ pm)a  
b. 散射模型命名 ]+5Y\~I  
c. 改变散射模型为“Tabulated BSDF”. LfvNO/:,  
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 ） u p zBd]  
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。 }XD=N#p@z  
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， *7{{z%5Pu  
g. 点击OK NC3XJ 4  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 8/@*6J  
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脚本代码： 6?';ip  
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'#Language "WWB-COM" ~zoZ{YqP  
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Option Explicit qFp]jbU  
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Sub Main s(:N>K5*  
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    'Cleanup .7HEI;4  
    ClearOutputWindow() 3F9dr@I.7  
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    Print "Merging RPC Photonics BSDF Data Files" sWq@E6,I  
    SetTextColor(255,0,0) x|*m ok  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." S" PJ@E}^E  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." Z*Fn2I4  
    SetTextColor(0,0,0) >CYz6G j  
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    'Current directory of this script (should be the same as the text files being merged) cS>xT cj  
    Dim cDir As String be]Zx`)k  
    cDir = MacroDir$ & "\" l]L"Ex{  
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    'Array which will be populated with the list of files to be merged ynn>d  
    Dim fList() As String, curFile As String z J V>;  
    GetFileList( cDir, fList ) 'Uo|@tK  
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    Print "" {tuGkRY2~  
    Print "Files found for merging:" E8.1jCL>{"  
    For Each curFile In fList CtHsi8m  
        Print Chr(9) & curFile KkSv23In  
    Next %O*)'ni  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. #U6~U6@  
    Dim nameArray() As String, sampName As String )gG_K$08?  
    nameArray = Split(fList(0)," 0-0.txt") ={I(i6  
    sampName  = nameArray(0) v
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    Print "" ~V/?/J$  
    Print "Sample name: " & Chr(9) & sampName #"TL*p  
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    'Open an output file and write the FRED header data (wp?tMN5#  
    Dim outFile As String 3JZ9 G79H  
    outFile = cDir & sampName & "_FRED.txt" Zzv,p  
    Open outFile For Output As #1 R}$A>)%dx  
    Print #1, "type bsdf_data" CMfR&G,)  
    Print #1, "format angles=deg bsdf=value scale=1" S^)xioKsJ  
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    'Loop the file list, skip the two header lines and write the remaining data to file e9eBD   
    Dim lineArray() As String, curLine As Long cKt8e^P  
    For Each curFile In fList 51puR8AG>  
        Print "Merging data from file " & curFile `7_s@4:  
        ReadFile( cDir & curFile, lineArray ) eSSv8[u  
        For curLine = 2 To UBound(lineArray) JjG>$z  
            Print #1, lineArray(curLine) &z"yls  
        Next KCfcEz  
    Next 7.B]B,]  
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    'Close the output file T0BM:ofx  
    Close #1 /pz(s+4=  
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    Print "Finished merging RPC data for sample " & sampName +w+qTZyky  
    Print "FRED formatted data file: " & Chr(9) & outFile Jek)`D  
End Sub MU~nvs;:  
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'Utility function to read the contents of a file into an array of strings. -;t]e6[  
Function ReadFile(ByVal fileName As String, _ d<v)ovQJ]  
                  ByRef lineArray() As String) As Long E"b"VB  
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    ReadFile = -1 !,N),xG}~  
    Dim oFSO As Object 2_;3B4GDF  
    Set oFSO = CreateObject("Scripting.FileSystemObject") A@OSh6/{h  
    Erase lineArray oW8 hC  
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    Dim fid As Long 4vf,RjB-5  
    If oFSO.fileexists( fileName ) Then qjd8Q  
        fid = FreeFile() u9)<i]2  
        Open fileName For Input As fid ' Y.s}Duj  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) \B D'"  
        Close fid YGr^uTQb  
    End If S-)%#  
    Set oFSO = Nothing LxxFosi8  
    Return UBound( lineArray ) X&({`Uw<K  
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End Function >-YWq  
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Sub GetFileList( ByVal in_dir As String, _ .+hM1OF`x  
                 ByRef in_flist() As String ) Y7 `i~K;  
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    'Redimension the file list array i:,37INMt  
    Erase in_flist s1NRUV2E  
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    'Tracks how many files are found }mSfg  
    Dim fCount As Long cakb.Q  
    fCount = 0 [vY? !  
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    'Recurse directory and search for text files X?Mc"M  
    Dim f As String kQMALS@R  
    f = Dir$(in_dir & "*.txt") ok7yFm1\  
    While f <> "" rocG;$[  
        ReDim Preserve in_flist(fCount) #35@YMF  
        in_flist(fCount) = f &GH,is  
        fCount += 1 :
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        f = Dir$() o`]u&  
    Wend FGG7;0(  
    ReDim Preserve in_flist(fCount-1) Qs.g%  
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End Sub {^VvL'n