[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： 7$Lt5rn"}  
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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。 ksF4m_E>YB  
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背景： ;n.SRy6
 
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。 rN`-ak  
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。 ftP]WGSS>  
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步骤 CIAKXYM  
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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。 I36ClOG  
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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） @^nE^;  
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 ;R^=($X  
例如下所示： /~P4<1  
Sample name:  EDF-C1-56 N\85fPSMG|  
Merging data from file EDF-C1-56 0-0.txt 56H~MnX  
Finished merging RPC data for sample EDF-C1-56 wc?YzXP+  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt f9^MLb6)  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 U\dLq&=V  
a. 创建一个新的散射库 fcw/l,k9  
b. 散射模型命名 pXK-,7-  
c. 改变散射模型为“Tabulated BSDF”. '-_tF3x  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） &"clBRVg  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 ~>rnq7j  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， A{)p#K8  
g. 点击OK N
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5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 9a]h;r8,9z  
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脚本代码： ltOsl-OpR  
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'#Language "WWB-COM" 3<}r+,j  
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Option Explicit Os1=V  
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Sub Main +4V"&S|&  
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    'Cleanup e]D TK*W~  
    ClearOutputWindow() wa
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    Print "Merging RPC Photonics BSDF Data Files" E<77Tj  
    SetTextColor(255,0,0) X9o6} %Y  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." ,9~qLQ0O  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." UGQHwz  
    SetTextColor(0,0,0) pW-aX)\DR  
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    'Current directory of this script (should be the same as the text files being merged) nmClP  
    Dim cDir As String CMU\DO  
    cDir = MacroDir$ & "\" 7$7#z\VWu  
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    'Array which will be populated with the list of files to be merged =A<a9@N}N  
    Dim fList() As String, curFile As String i(0%cNP7  
    GetFileList( cDir, fList ) "T~A*a^  
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    Print "" Vs, &  
    Print "Files found for merging:" W!)B%.Q  
    For Each curFile In fList /v7o!D1G  
        Print Chr(9) & curFile .r \g]  
    Next }=s64O9j  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. htOVt\+!34  
    Dim nameArray() As String, sampName As String Dj'+,{7,u  
    nameArray = Split(fList(0)," 0-0.txt") r^;1Sm  
    sampName  = nameArray(0) }/aqh;W  
    Print "" (gF{S*`  
    Print "Sample name: " & Chr(9) & sampName {3K`yDF  
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    'Open an output file and write the FRED header data +H "j-:E@t  
    Dim outFile As String quiX"lV(  
    outFile = cDir & sampName & "_FRED.txt" Wqas1yL_  
    Open outFile For Output As #1 M6z$*?<  
    Print #1, "type bsdf_data" SAokW,  
    Print #1, "format angles=deg bsdf=value scale=1" yu$xQ
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    'Loop the file list, skip the two header lines and write the remaining data to file TH? wXd\  
    Dim lineArray() As String, curLine As Long }PxPJ$o  
    For Each curFile In fList XWBTBL  
        Print "Merging data from file " & curFile o*:D/"gb  
        ReadFile( cDir & curFile, lineArray ) s@pIcNvx  
        For curLine = 2 To UBound(lineArray) R;H>#caJ  
            Print #1, lineArray(curLine) z;Dc#SZnO(  
        Next +/!y#&C&*  
    Next {@ Z%6%'9  
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    'Close the output file 6}?5Oy_XF2  
    Close #1 +lw*/\
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    Print "Finished merging RPC data for sample " & sampName S=g E'"LT  
    Print "FRED formatted data file: " & Chr(9) & outFile eRB K= X  
End Sub <E\vc6n  
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'Utility function to read the contents of a file into an array of strings. :zsMkdU  
Function ReadFile(ByVal fileName As String, _ ?5rM'O2  
                  ByRef lineArray() As String) As Long r<EwtO+x  
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    ReadFile = -1 xv0y?#`z  
    Dim oFSO As Object 4x?4[J~u[  
    Set oFSO = CreateObject("Scripting.FileSystemObject") 
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    Erase lineArray -[xbGSj{  
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    Dim fid As Long /H :Bu  
    If oFSO.fileexists( fileName ) Then /9SNXjfbt  
        fid = FreeFile() aHBM9%gV  
        Open fileName For Input As fid 5IFc"  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) xOdLct  
        Close fid Y&1Yc)*O  
    End If *a@78&N  
    Set oFSO = Nothing z9ZS&=>  
    Return UBound( lineArray ) xH{V.n&v  
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End Function gwN y
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Sub GetFileList( ByVal in_dir As String, _ vze|*dKS  
                 ByRef in_flist() As String ) R/kfbV-b  
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    'Redimension the file list array h3z9}'  
    Erase in_flist D<(VP{,G  
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    'Tracks how many files are found 0<42\ya  
    Dim fCount As Long 1owe'7\J  
    fCount = 0 E rnGX#@v  
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    'Recurse directory and search for text files ~uh,R-Q$  
    Dim f As String 1JF>0ijU@  
    f = Dir$(in_dir & "*.txt") g/`z.?  
    While f <> "" 0t.v  
        ReDim Preserve in_flist(fCount) J9XV:)Yv#  
        in_flist(fCount) = f >(eR0.x  
        fCount += 1 e\ O&Xe  
        f = Dir$() e4Xo(EY &  
    Wend HQ`A.E2  
    ReDim Preserve in_flist(fCount-1) _>i<`k  
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End Sub Z~HLa