[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： 3)+
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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。 ?Dk&5d^d  
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背景： Kr'5iFK7  
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。 oefhJM!y  
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;EA-  
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步骤 d'Z  
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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。 U6
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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） 0WI3m2i  
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 (},TZ+u
 
例如下所示： +WYXj  
Sample name:  EDF-C1-56 *CtOQ  
Merging data from file EDF-C1-56 0-0.txt 'X
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Finished merging RPC data for sample EDF-C1-56 .A`Q!  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt 9'|NF<  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 {m/h3hjFa  
a. 创建一个新的散射库 co$I htOv  
b. 散射模型命名 5&\%  
c. 改变散射模型为“Tabulated BSDF”. 8QN#PaY  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） 
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e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 :Ojsj_Z;;  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， +84JvOkWi  
g. 点击OK eS/4gM7%  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 s*k[Fbi  
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脚本代码： #sK:q&/G`  
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'#Language "WWB-COM" ,dM}B-  
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Option Explicit yJJNr]oq  
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Sub Main ivKhzU+  
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    'Cleanup i+)9ItZr  
    ClearOutputWindow() CnT]uU  
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    Print "Merging RPC Photonics BSDF Data Files" O.%' 47A  
    SetTextColor(255,0,0) Jf-4Q!  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." 6 ZutU ~HS  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." H53dy*wb$  
    SetTextColor(0,0,0) mgk<PY  
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    'Current directory of this script (should be the same as the text files being merged) O|opNr  
    Dim cDir As String [nO\Q3c|@$  
    cDir = MacroDir$ & "\" *-gd k9  
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    'Array which will be populated with the list of files to be merged _<`j?$P  
    Dim fList() As String, curFile As String }6;v`1Hr  
    GetFileList( cDir, fList ) s3sAw~++  
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    Print "" MY]Z@  
    Print "Files found for merging:" df=G}M(  
    For Each curFile In fList |]tIE{d  
        Print Chr(9) & curFile Gf(|?" H  
    Next "w#jC~J<W  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. 9U[ A   
    Dim nameArray() As String, sampName As String /~?'zr  
    nameArray = Split(fList(0)," 0-0.txt") OaeGukhX&  
    sampName  = nameArray(0) &R\t<X9 n  
    Print "" Q:6i 3 Nr/  
    Print "Sample name: " & Chr(9) & sampName ^gY^I`"e6  
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    'Open an output file and write the FRED header data BB&7VSgc-  
    Dim outFile As String /1F5khN  
    outFile = cDir & sampName & "_FRED.txt" gr?[KDl~  
    Open outFile For Output As #1 9"5J-a'  
    Print #1, "type bsdf_data" `*5_`^t   
    Print #1, "format angles=deg bsdf=value scale=1" %s}c#n)N  
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    'Loop the file list, skip the two header lines and write the remaining data to file 21b  
    Dim lineArray() As String, curLine As Long 8<gYB$* S  
    For Each curFile In fList AATiI+\S  
        Print "Merging data from file " & curFile >h?!6L- d  
        ReadFile( cDir & curFile, lineArray ) ZK1H%&P=R  
        For curLine = 2 To UBound(lineArray) B:-qUuS?R  
            Print #1, lineArray(curLine) ^W&qTSjh  
        Next O$=[m9
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    Next N,Fmu  
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    'Close the output file jea{BhdUr  
    Close #1 lr>P/W\  
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    Print "Finished merging RPC data for sample " & sampName ;7jszs.6%  
    Print "FRED formatted data file: " & Chr(9) & outFile yfq Vx$YL  
End Sub %r1NRg8  
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'Utility function to read the contents of a file into an array of strings. 8F?6Aq1B  
Function ReadFile(ByVal fileName As String, _ O] T'\6w  
                  ByRef lineArray() As String) As Long 3#O Rfr(  
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    ReadFile = -1 k[{h
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    Dim oFSO As Object =UGyZV:z5  
    Set oFSO = CreateObject("Scripting.FileSystemObject") rD"$,-h  
    Erase lineArray cPFs K*w  
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    Dim fid As Long it Byw1/  
    If oFSO.fileexists( fileName ) Then g4Y1*`}2f  
        fid = FreeFile() nY]5pOF:  
        Open fileName For Input As fid ~F gxhK2+  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) ;\[n{<   
        Close fid >S<`ri'5_  
    End If }0Q_yuzx0m  
    Set oFSO = Nothing 36 &ghx  
    Return UBound( lineArray ) V7+fNr]I  
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End Function 8%eWB$<X  
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Sub GetFileList( ByVal in_dir As String, _ c#-o@`Po  
                 ByRef in_flist() As String ) {`-f<>N3  
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    'Redimension the file list array zla^j,  
    Erase in_flist =tkO^  
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    'Tracks how many files are found (
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    Dim fCount As Long `#/0q*$  
    fCount = 0 y'$Re  
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    'Recurse directory and search for text files e7n[NVrX  
    Dim f As String t<F*ODn  
    f = Dir$(in_dir & "*.txt") VxgP^*  
    While f <> "" DlMT<ld  
        ReDim Preserve in_flist(fCount) |\#~  
        in_flist(fCount) = f kYW>o}J|  
        fCount += 1 _l{`lQ
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        f = Dir$() &U
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    Wend HX)oN8  
    ReDim Preserve in_flist(fCount-1) pXoD*o b  
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End Sub bR\Oyd~e