[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： }h=PW'M{  
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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。 B]H8^   
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背景： Rpv[rvK'  
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。 :EAh%q  
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。 
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步骤 ``P9f
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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。 h=
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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） hPUAm6b;  
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 ,:e~aG,B  
例如下所示： swxX3GR  
Sample name:  EDF-C1-56 ;Y[D#Ja-  
Merging data from file EDF-C1-56 0-0.txt m$_b\^we  
Finished merging RPC data for sample EDF-C1-56 OxYAM,F  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt DnFzCJ  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 /IG{j}  
a. 创建一个新的散射库 Uns%6o  
b. 散射模型命名 s~].iQJ{B  
c. 改变散射模型为“Tabulated BSDF”. a_V\[V{R=  
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 ） .wD $Bsm`t  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 >x JzV  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， 4`,7tj  
g. 点击OK Uffwzd!  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 vMB61 |O  
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脚本代码： uQKQC?w  
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'#Language "WWB-COM" %+=;4tHJ  
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Option Explicit v>#Njgo  
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Sub Main N?ccG\t  
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    'Cleanup {KNaJ/:>W  
    ClearOutputWindow() (<r)xkn  
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    Print "Merging RPC Photonics BSDF Data Files" )b #5rQ  
    SetTextColor(255,0,0) -n&&d8G^s  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." LNWS  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." b^Z2Vf:k]  
    SetTextColor(0,0,0) ea"X$<s>-  
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    'Current directory of this script (should be the same as the text files being merged) L@{'J  
    Dim cDir As String &liON1GLM  
    cDir = MacroDir$ & "\" "D _r</b  
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    'Array which will be populated with the list of files to be merged 5[Vr {^)  
    Dim fList() As String, curFile As String (s,&,I=@  
    GetFileList( cDir, fList ) Jg;[k  
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    Print "" %-blx)Pc  
    Print "Files found for merging:" |${4sUR  
    For Each curFile In fList ~^1y(-cw  
        Print Chr(9) & curFile 7P+1W \  
    Next ZPmqoR[  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. iz#R)EB/g  
    Dim nameArray() As String, sampName As String P+o"]/7U  
    nameArray = Split(fList(0)," 0-0.txt") rJpr;QKf%  
    sampName  = nameArray(0) %6320 x  
    Print "" X$>F78e*  
    Print "Sample name: " & Chr(9) & sampName E:x@O8F  
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    'Open an output file and write the FRED header data E2'Wzrovlo  
    Dim outFile As String BA c+T
 
    outFile = cDir & sampName & "_FRED.txt" /P*XB%y  
    Open outFile For Output As #1 ChTq!W  
    Print #1, "type bsdf_data" o'#& =h$_  
    Print #1, "format angles=deg bsdf=value scale=1" .jCGtR )%  
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    'Loop the file list, skip the two header lines and write the remaining data to file ayA;6Qt  
    Dim lineArray() As String, curLine As Long Y1-dpML   
    For Each curFile In fList R'k`0  
        Print "Merging data from file " & curFile vTK%4=|1}!  
        ReadFile( cDir & curFile, lineArray ) <-v zS;  
        For curLine = 2 To UBound(lineArray) HDHG~<s  
            Print #1, lineArray(curLine) [=>=5'-  
        Next l<+[l$0#  
    Next PY5&Fwjc  
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    'Close the output file m !*F5x  
    Close #1 SUc%dpXZa  
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    Print "Finished merging RPC data for sample " & sampName rtuaU=U  
    Print "FRED formatted data file: " & Chr(9) & outFile ]%E
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End Sub Fa%1]R  
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'Utility function to read the contents of a file into an array of strings. tP@NQCo  
Function ReadFile(ByVal fileName As String, _ Kyh>O)"G^%  
                  ByRef lineArray() As String) As Long -{\(s=%  
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    ReadFile = -1 |Mb{0mKb  
    Dim oFSO As Object ,u `xneOs  
    Set oFSO = CreateObject("Scripting.FileSystemObject") )dkU4]  
    Erase lineArray msmW2Zc  
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    Dim fid As Long `9^tuR,  
    If oFSO.fileexists( fileName ) Then CVfV   
        fid = FreeFile() s* (a  
        Open fileName For Input As fid h^\vk!Q-d  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) AM}2=Ip  
        Close fid XRV]u|w=g  
    End If 1C
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    Set oFSO = Nothing aJ+V]WmA  
    Return UBound( lineArray ) 3YvKHn|V"  
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End Function =Wcvb?;*  
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Sub GetFileList( ByVal in_dir As String, _ "#~>q(
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                 ByRef in_flist() As String ) Mh)?A/e  
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    'Redimension the file list array 
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    Erase in_flist >of34C"DI  
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    'Tracks how many files are found aD: #AmbJ  
    Dim fCount As Long Hm2Y% 4i%  
    fCount = 0 &*v\t\]  
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    'Recurse directory and search for text files VRd7H.f,A6  
    Dim f As String gA2Wo+\^bq  
    f = Dir$(in_dir & "*.txt") sy
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    While f <> "" Y}ogwg&  
        ReDim Preserve in_flist(fCount) (GC
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        in_flist(fCount) = f ]DVr-f ~  
        fCount += 1 K0.aU  
        f = Dir$() 9nG^_.}|  
    Wend {,%&}kd>  
    ReDim Preserve in_flist(fCount-1) i=gZ8Q=H  
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End Sub tA
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