[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： |94o P>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。 Wu|MNB?M  
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背景： qWWt5rJ  
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。 Dqc GzTz  
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。 /Mw;oP{&b  
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步骤 BLaNS4e  

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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。 g~.#.S ds  
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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） FNF`Z  
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 S#8)N`  
例如下所示： J
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Sample name:  EDF-C1-56 ]4[%Sv6]G  
Merging data from file EDF-C1-56 0-0.txt i\/'w]  
Finished merging RPC data for sample EDF-C1-56 zz(|V  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt )~R[aXkvY  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 V?G%-+^  
a. 创建一个新的散射库 =:w,wI.  
b. 散射模型命名 (2>q  
c. 改变散射模型为“Tabulated BSDF”. pKq[F*Lut  
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 ） "h[)5V{  
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。 eCN:  
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， Y %bb-|\W  
g. 点击OK m{RXt  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 E%D.a=UX,  
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脚本代码： YU[#4f~  
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'#Language "WWB-COM" 9XDSL[[  
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Option Explicit \rxjvV4fcZ  
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Sub Main O9By5j 4  
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    'Cleanup Bi \fB-|  
    ClearOutputWindow() `3VI9GmQ  
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    Print "Merging RPC Photonics BSDF Data Files" ~?aFc)  
    SetTextColor(255,0,0) F5cNF5  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." !<~.>5UQ  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." _wb]tE ~g  
    SetTextColor(0,0,0) XtZd% #2},  
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    'Current directory of this script (should be the same as the text files being merged) WUz69o be  
    Dim cDir As String 3>L5TYa  
    cDir = MacroDir$ & "\" Yq|_6zbYf  
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    'Array which will be populated with the list of files to be merged "k@[7 7  
    Dim fList() As String, curFile As String e/+.^ '{  
    GetFileList( cDir, fList ) T|BlFJ0"  
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    Print "" Ty{ SZUJ  
    Print "Files found for merging:" @#W4?L*D  
    For Each curFile In fList J>T98y/))  
        Print Chr(9) & curFile ub>:dNBN  
    Next UTu~"uCR  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. $#5'c+0  
    Dim nameArray() As String, sampName As String S{e3aqT#N  
    nameArray = Split(fList(0)," 0-0.txt") V~/@KU8cH  
    sampName  = nameArray(0) >S}X)4  
    Print "" JSju4TQ4  
    Print "Sample name: " & Chr(9) & sampName =e#h;x2  
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    'Open an output file and write the FRED header data RZ{O6~VH  
    Dim outFile As String J`[jub  
    outFile = cDir & sampName & "_FRED.txt" MmvJ
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    Open outFile For Output As #1 R8lja%+0$  
    Print #1, "type bsdf_data" gS[B;
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    Print #1, "format angles=deg bsdf=value scale=1" ;Qt/(/  
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    'Loop the file list, skip the two header lines and write the remaining data to file `.~S/$a.&  
    Dim lineArray() As String, curLine As Long s92ol0`  
    For Each curFile In fList 3
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        Print "Merging data from file " & curFile 1@'I eywg  
        ReadFile( cDir & curFile, lineArray ) AHuIA{AdUR  
        For curLine = 2 To UBound(lineArray) 2Uf/'  
            Print #1, lineArray(curLine) [75?cQD  
        Next hTEb?1CXU  
    Next &Lzd*}7  
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    'Close the output file N\tFK*U^I  
    Close #1 ,jz~Np_2  
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    Print "Finished merging RPC data for sample " & sampName 1I'Q{X&B  
    Print "FRED formatted data file: " & Chr(9) & outFile @?]>4+Oa0  
End Sub .6rbn8h  
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'Utility function to read the contents of a file into an array of strings. rt*>)GI]b  
Function ReadFile(ByVal fileName As String, _ 5K?
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                  ByRef lineArray() As String) As Long 8,h!&9  
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    ReadFile = -1 ->;2CcpHB  
    Dim oFSO As Object K0vS  
    Set oFSO = CreateObject("Scripting.FileSystemObject") t%^&b'/Z  
    Erase lineArray gx^!&>eIb#  
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    Dim fid As Long 38X{>*  
    If oFSO.fileexists( fileName ) Then l*wGKg"x3  
        fid = FreeFile() [x, `)Fk  
        Open fileName For Input As fid "R)n1,0  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) E+<GsN]  
        Close fid xuqG)HthRS  
    End If KCZ<#ca^  
    Set oFSO = Nothing q4!\^HwQ  
    Return UBound( lineArray ) )AcevEHB  
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End Function ydY(*]  

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Sub GetFileList( ByVal in_dir As String, _ *(vh|  
                 ByRef in_flist() As String ) t&x\@p9  
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    'Redimension the file list array K9}Brhe  
    Erase in_flist c]U+6JH  
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    'Tracks how many files are found 1K|F;p  
    Dim fCount As Long ct,;V/Dx  
    fCount = 0 ?9eiT:2  
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    'Recurse directory and search for text files T)q Uf H  
    Dim f As String /G]/zlUE  
    f = Dir$(in_dir & "*.txt") * Z)j"i  
    While f <> "" &F7_0iAP(  
        ReDim Preserve in_flist(fCount) 4=y&}3om(0  
        in_flist(fCount) = f W79.Nj2`  
        fCount += 1 @U?&1.\  
        f = Dir$() 2Rwd\e.z  
    Wend sieC7raO  
    ReDim Preserve in_flist(fCount-1) >e-0A  
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End Sub *+6iXMwe