[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： #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。 h;@c%Vm  
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背景： wn^#`s!]U  
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。 {dXTj7  
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。 2x>7>;>  
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步骤 |kH.o=  
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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。 'hE'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） =A!rZG  
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 8>@JW]  
例如下所示： lb$_$+@Vr  
Sample name:  EDF-C1-56 RL:B.Lv/W  
Merging data from file EDF-C1-56 0-0.txt )X;051Q  
Finished merging RPC data for sample EDF-C1-56
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FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt 06O_!"GD}  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 ZNne
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a. 创建一个新的散射库 9
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b. 散射模型命名 c<,LE@V  
c. 改变散射模型为“Tabulated BSDF”. c7~R0nP  
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 ） ]J[d8S5  
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。 .uVd'  
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， a2Nxpxho  
g. 点击OK =[8K#PZ$w  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 U(0FL6sPC  
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脚本代码： 7nNNc[d*=  
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'#Language "WWB-COM" `!t-$i  
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Option Explicit 0PqI^|!  
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Sub Main V*ao@;sD  
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    'Cleanup &&m3E=K!^  
    ClearOutputWindow() e@qH!.g)  

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    Print "Merging RPC Photonics BSDF Data Files" ]iGeqwT  
    SetTextColor(255,0,0) E_En"r)y  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." `<yQ`Y_X  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." F$(ak;v}  
    SetTextColor(0,0,0) l 9 wO x  
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    'Current directory of this script (should be the same as the text files being merged) hVmnXT 3Z  
    Dim cDir As String mE`qA*=?  
    cDir = MacroDir$ & "\" M,S'4Szuk  
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    'Array which will be populated with the list of files to be merged $:%E<j4Dn  
    Dim fList() As String, curFile As String v+"4YIN  
    GetFileList( cDir, fList ) z4:<?K  
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    Print "" JC%&d
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    Print "Files found for merging:" /ZD6pF  
    For Each curFile In fList H)i|?3Ip  
        Print Chr(9) & curFile iX6>u4~(  
    Next &n )MGg1%  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. *s*Y uY%y  
    Dim nameArray() As String, sampName As String ,bXZ<RY$  
    nameArray = Split(fList(0)," 0-0.txt") F^'$%XKV  
    sampName  = nameArray(0) i? ~-%  
    Print "" VK]U*V1  
    Print "Sample name: " & Chr(9) & sampName \OA{&G.  
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    'Open an output file and write the FRED header data nV7Vc;  
    Dim outFile As String _ Lb"
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    outFile = cDir & sampName & "_FRED.txt" #'q7 x  
    Open outFile For Output As #1 7Vsp<s9bj  
    Print #1, "type bsdf_data" oDV6[e  
    Print #1, "format angles=deg bsdf=value scale=1" E{&MmrlL,  
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    'Loop the file list, skip the two header lines and write the remaining data to file .Zczya  
    Dim lineArray() As String, curLine As Long IGcq*mR=  
    For Each curFile In fList q:/df]Ntt  
        Print "Merging data from file " & curFile dv>n38&mDQ  
        ReadFile( cDir & curFile, lineArray ) UMR?q0J  
        For curLine = 2 To UBound(lineArray) }a||@unr  
            Print #1, lineArray(curLine) +q}t%K5  
        Next M&j|5UH%.  
    Next az6&  
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    'Close the output file 7Hr_ZwO/^  
    Close #1 (MI>7| ';  
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    Print "Finished merging RPC data for sample " & sampName k?14'X*7yu  
    Print "FRED formatted data file: " & Chr(9) & outFile 80*hi)ux[  
End Sub cx$IWQf2  
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'Utility function to read the contents of a file into an array of strings. Sp80xV_B  
Function ReadFile(ByVal fileName As String, _ Y/kq!)u;%L  
                  ByRef lineArray() As String) As Long x/umwT,ov  
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    ReadFile = -1 \;)g<
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    Dim oFSO As Object E7fQ9]  
    Set oFSO = CreateObject("Scripting.FileSystemObject") a)JXxst  
    Erase lineArray =Z  
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    Dim fid As Long #m.e9MU  
    If oFSO.fileexists( fileName ) Then }_]AQN$'G  
        fid = FreeFile() TC?B_;a  
        Open fileName For Input As fid C7FQc{  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) sQa;l]O:NC  
        Close fid D=-}&w_T"  
    End If @gD)pH  
    Set oFSO = Nothing LpU}.  
    Return UBound( lineArray ) [yXmnrxA  
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End Function `FMo;
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Sub GetFileList( ByVal in_dir As String, _ {h?pvH_>  
                 ByRef in_flist() As String ) XMuZ
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    'Redimension the file list array J
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    Erase in_flist b# N"}-\^  
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    'Tracks how many files are found {Yj5Mj|#  
    Dim fCount As Long 2!^=G=H/  
    fCount = 0 b_31\  
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    'Recurse directory and search for text files `I5^zi8  
    Dim f As String fHup&|.  
    f = Dir$(in_dir & "*.txt") /| v.A\:  
    While f <> "" Jj-\Eb?  
        ReDim Preserve in_flist(fCount) OyZR&,q  
        in_flist(fCount) = f =Z^5'h~  
        fCount += 1 DXLXGvcM  
        f = Dir$() N)X Tmh2v|  
    Wend r<UVO$N  
    ReDim Preserve in_flist(fCount-1) k&dXK  
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End Sub z'q~%1t