[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： $4^SWT.  
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RPC Photonics公司有高品质的的工程漫射体BSDF测试数据，但它对于FRED帮助甚少，下面这个步骤描述了如何利用FRED脚本转换RPC Photonics提供的TXT文件，并将数据直接应用到FRED的Tabulated scatter 散射模型。 EK5$z>k>m  
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背景： _-lE$
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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。 ,<* I5:  
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。 s[sv4hq  
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步骤 )AxD|A  
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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。 BvsSrse  
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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） E]rXp~AZm  
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 -iS^VzI|I  
例如下所示： ^?Mp(o  
Sample name:  EDF-C1-56 rVqQo`K\  
Merging data from file EDF-C1-56 0-0.txt n."n?C'{  
Finished merging RPC data for sample EDF-C1-56 Ny^f
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FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt [#C6K '  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 s*[ I"iE  
a. 创建一个新的散射库 L
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b. 散射模型命名 /wLGf]0  
c. 改变散射模型为“Tabulated BSDF”. >7PQOQMW'
 
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 ） M2|!,2  
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。 B=r DU$z  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， O7Jux-E1C  
g. 点击OK
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5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 4hy-M>!D|  
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脚本代码： j(Lz& *4  
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'#Language "WWB-COM" Lo%vG{yTr  
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Option Explicit {KNaJ/:>W  
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Sub Main hNM8H  
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    'Cleanup JI[8n$pr]  
    ClearOutputWindow() v?O
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    Print "Merging RPC Photonics BSDF Data Files" q* p  
    SetTextColor(255,0,0) Q?i_Nl/|  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." } +}nrJv  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." oI{.{]  
    SetTextColor(0,0,0) (vO3vCYeQ  
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    'Current directory of this script (should be the same as the text files being merged) <E4(KE  
    Dim cDir As String EL$DvJ~  
    cDir = MacroDir$ & "\" b
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    'Array which will be populated with the list of files to be merged xrPZy*Y,  
    Dim fList() As String, curFile As String `FPQOa*%3  
    GetFileList( cDir, fList ) =U3S"W %  
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    Print "" ~i"=:D  
    Print "Files found for merging:" reN\|?0{  
    For Each curFile In fList &SE}5
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        Print Chr(9) & curFile ks0Q+YW  
    Next R^.PKT2E  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. KMj\A d  
    Dim nameArray() As String, sampName As String t2o{=!$WH  
    nameArray = Split(fList(0)," 0-0.txt") CW+kKN  
    sampName  = nameArray(0) 9 8|sWI3B  
    Print "" @&}}tALi  
    Print "Sample name: " & Chr(9) & sampName 8M*+ |  
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    'Open an output file and write the FRED header data SA +d4P_T  
    Dim outFile As String e,xL~P{|  
    outFile = cDir & sampName & "_FRED.txt" <a"(B*bBd  
    Open outFile For Output As #1 /aI@2]|~  
    Print #1, "type bsdf_data" \#HW.5  
    Print #1, "format angles=deg bsdf=value scale=1" {$z54nvw$  
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    'Loop the file list, skip the two header lines and write the remaining data to file !i;6!w  
    Dim lineArray() As String, curLine As Long ]o<]A[<  
    For Each curFile In fList N:<$]x>  
        Print "Merging data from file " & curFile /*qRbN  
        ReadFile( cDir & curFile, lineArray ) ,ErfTg&^  
        For curLine = 2 To UBound(lineArray) 1,wcf,  
            Print #1, lineArray(curLine) [Arf!W-QG  
        Next ='h2z"}\Bn  
    Next 4/b.;$  
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    'Close the output file 61S;M8tNv  
    Close #1 e'K~WNT  
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    Print "Finished merging RPC data for sample " & sampName G4@r_VP\  
    Print "FRED formatted data file: " & Chr(9) & outFile }3{eVct#|  
End Sub ,u `xneOs  
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'Utility function to read the contents of a file into an array of strings. VmqJMU>.  
Function ReadFile(ByVal fileName As String, _ 3=.YQE0!dx  
                  ByRef lineArray() As String) As Long 0SI@`C*1o  
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    ReadFile = -1 r^~+<"  
    Dim oFSO As Object h^\vk!Q-d  
    Set oFSO = CreateObject("Scripting.FileSystemObject") AM}2=Ip  
    Erase lineArray XRV]u|w=g  
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    Dim fid As Long Oh! {E5!)  
    If oFSO.fileexists( fileName ) Then i1B!oZ3q  
        fid = FreeFile() .?45:Ey~g  
        Open fileName For Input As fid NIs7v  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) iJzB
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        Close fid TPN+jK  
    End If VE+H! ob A  
    Set oFSO = Nothing h$02#(RHJ  
    Return UBound( lineArray ) izl6L  
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End Function RrMEDMhk6  
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Sub GetFileList( ByVal in_dir As String, _ 7zG r+Px  
                 ByRef in_flist() As String ) l!tR
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    'Redimension the file list array {srP3ll P  
    Erase in_flist (uC8M,I\  
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    'Tracks how many files are found @"7S$@cO  
    Dim fCount As Long b}
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    fCount = 0 *5fe
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    'Recurse directory and search for text files BP3Ha8/X  
    Dim f As String G=:/v  
    f = Dir$(in_dir & "*.txt") I\mF dE  
    While f <> "" ~[%CUc"  
        ReDim Preserve in_flist(fCount) E=8'!  
        in_flist(fCount) = f "`% ,l|D  
        fCount += 1 27SHj9I  
        f = Dir$() Ev7.!  
    Wend ;u<Ah?w=Z  
    ReDim Preserve in_flist(fCount-1) (tg.]q_=u  
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End Sub :{%[6lE^G