[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： ''3b[<  
Q8?:L<
A  
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。 +5xk6RP   
HBiUp$(mB  
背景： G/y;o3/[Z  
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。 Qf.]Mw?Bm  
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。 ;JV(!8[  
pZV=Co3!I  
9D,/SZ-v  
owKOH{otf  
步骤 zn2Qp  
Xn #v!  
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。 n1PV/ Z  
+XoY@|Djd  
HtAO9  
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） xjH({(/B>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 MNu\=p\Eq  
例如下所示： =l+~}/7'Z  
Sample name:  EDF-C1-56 {jOV8SVL  
Merging data from file EDF-C1-56 0-0.txt 2 i97  
Finished merging RPC data for sample EDF-C1-56 "pTU&He  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt F/w*[Xi Sh  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 |}D5q| d@n  
a. 创建一个新的散射库 ]CGH )4Pe  
b. 散射模型命名  RI&V:1  
c. 改变散射模型为“Tabulated BSDF”. S:{`eDk\A_  
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 ） X-j3=8wPM  
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。 ,lb >  
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{IxQk  
g. 点击OK SmCtwcB1  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 ykD-
L^}  
$VnPs!a  
tf4clzSTa  
脚本代码： Rg%Xy`gS  
ES ?6  
'#Language "WWB-COM" 3_N1y  
1HBWOV7z.?  
Option Explicit tKYg  
Q3rLCg,;  
Sub Main V@pUU~6R  
>Y=qSg>Ik  
    'Cleanup NKMVp/66D  
    ClearOutputWindow() >9,:i)m_  
9=.7[-6i9  
    Print "Merging RPC Photonics BSDF Data Files" f6`W(OiE  
    SetTextColor(255,0,0) Svt%*j  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." >/G[Oo  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." +c' n,O~3  
    SetTextColor(0,0,0) 9yWSlbPr]  
KskPFXxP  
    'Current directory of this script (should be the same as the text files being merged) cf%aOHYI*  
    Dim cDir As String ZDx1v_xr  
    cDir = MacroDir$ & "\" ?D['>Rzu  
ZwMd 22  
    'Array which will be populated with the list of files to be merged fU|4^p)  
    Dim fList() As String, curFile As String S~U5xM^s  
    GetFileList( cDir, fList ) p<c1$O*  
H^<?h6T  
    Print "" CPcB17!  
    Print "Files found for merging:" m'WGK`WIm  
    For Each curFile In fList ce7$# #f  
        Print Chr(9) & curFile 4@=[rZb9  
    Next ?d_vD@+\  
u3\_![Jt?  
    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. y=zs6
HaS  
    Dim nameArray() As String, sampName As String Lw`}o`D  
    nameArray = Split(fList(0)," 0-0.txt") m@"p#pt(_  
    sampName  = nameArray(0) s){R/2O3F  
    Print "" F]cc?r312  
    Print "Sample name: " & Chr(9) & sampName BC R]K  
>nO[5  
    'Open an output file and write the FRED header data s8SCEpz  
    Dim outFile As String 7%W@Hr,%F  
    outFile = cDir & sampName & "_FRED.txt" Ct]? /  
    Open outFile For Output As #1 oI"gQFGu`u  
    Print #1, "type bsdf_data" @B9#Hrc  
    Print #1, "format angles=deg bsdf=value scale=1" YGhHIziI  
j.:f=`xf  
    'Loop the file list, skip the two header lines and write the remaining data to file M7ug< 8i  
    Dim lineArray() As String, curLine As Long =z'533C  
    For Each curFile In fList i}@5<&J  
        Print "Merging data from file " & curFile lM.k*`$  
        ReadFile( cDir & curFile, lineArray ) +f,I$&d.V  
        For curLine = 2 To UBound(lineArray) H%;pPkIi  
            Print #1, lineArray(curLine) 1p
T/`x  
        Next Tx(=4ALY  
    Next Tvw(Sq};  
Fl++rUT  
    'Close the output file Ca0t}`
<S  
    Close #1 Y{L|ja%9?  
_#w5hXcu  
    Print "Finished merging RPC data for sample " & sampName \>+BvF  
    Print "FRED formatted data file: " & Chr(9) & outFile r]&&*:  
End Sub :s|xa u=  
<9`/Y"\p  
'Utility function to read the contents of a file into an array of strings. hcQv!!Q"k$  
Function ReadFile(ByVal fileName As String, _ [Rzn>  
                  ByRef lineArray() As String) As Long /_r{7Gq.  
D66!C{  
    ReadFile = -1 r8!M8Sc  
    Dim oFSO As Object b<KKF'  
    Set oFSO = CreateObject("Scripting.FileSystemObject") #DcK{
|ty  
    Erase lineArray T7Yg^ -"  
4'XCO+i#  
    Dim fid As Long bM $WU?Z  
    If oFSO.fileexists( fileName ) Then RueL~$*6.~  
        fid = FreeFile() LY!.u?D`P  
        Open fileName For Input As fid O9F#gO|!  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf)  U66oe3W  
        Close fid \fL:Ie  
    End If ]BBjFs4#  
    Set oFSO = Nothing &qZ:"k  
    Return UBound( lineArray ) 8wA'a'V.  
k!m9 l1x  
End Function P4~C0z  
jVdB- y/r  
Sub GetFileList( ByVal in_dir As String, _ )"<:Md$7  
                 ByRef in_flist() As String ) (+0yZ7AZ  
WK6|e[iP  
    'Redimension the file list array h:'wtn@l(  
    Erase in_flist pc<A ,?  
Toc="F`SW  
    'Tracks how many files are found (Y]G6> Oa  
    Dim fCount As Long G7H'OB &  
    fCount = 0 ,Mw;kevw  
+W9#^  
    'Recurse directory and search for text files Y/< ],1U  
    Dim f As String Oe}6jcb6&  
    f = Dir$(in_dir & "*.txt") %q 7gl;'  
    While f <> "" 4';(\42  
        ReDim Preserve in_flist(fCount) =qVD"Z]z  
        in_flist(fCount) = f %1VfTr5  
        fCount += 1 ;?0r,0l2$  
        f = Dir$() 0|_d{/VK4  
    Wend w"K;e(S  
    ReDim Preserve in_flist(fCount-1) . 'rC'FT  
?_7^MP>  
End Sub " )_-L8