[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： a?IL6$z  
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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。 #0HF7C3  
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背景： jF'azlT  
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。  4^L+LY  
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。 E6-alBi%  
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步骤 "/).:9],}  
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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。 -L/5Nbup  
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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） ")U`Wgx  
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 `j59MSuK  
例如下所示： \jdpL1  
Sample name:  EDF-C1-56 wR;_x x  
Merging data from file EDF-C1-56 0-0.txt 13]sZ([B%|  
Finished merging RPC data for sample EDF-C1-56 4"e7 43(  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt Cm;WQuv@  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 ,/\%-u? 1x  
a. 创建一个新的散射库  ##7,  
b. 散射模型命名 .Lrdw3(  
c. 改变散射模型为“Tabulated BSDF”. f8E S GU  
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 ） 1rV?^5  
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。 ku*|?uF  
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， ~BVg#_P  
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 vm+EzmO,!  
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脚本代码： t_YiF%}s&#  
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'#Language "WWB-COM" #Dx$KPD  
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Option Explicit Mi\f?  
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Sub Main 5|:=
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    'Cleanup -aGv#!aIl  
    ClearOutputWindow() MB\vgKY  
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    Print "Merging RPC Photonics BSDF Data Files" ^HKxaW9W  
    SetTextColor(255,0,0) LiJ;A*  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." LX j Tqp'  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." C+}uH:I'L  
    SetTextColor(0,0,0) K/Axojo  
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    'Current directory of this script (should be the same as the text files being merged) VLtb16|  
    Dim cDir As String !.iA^D//]  
    cDir = MacroDir$ & "\" mxjY-Kq  
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    'Array which will be populated with the list of files to be merged 94W9P't  
    Dim fList() As String, curFile As String 2o/}GIKj  
    GetFileList( cDir, fList ) 2P9hx5PiV  
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    Print "" G <m{o  
    Print "Files found for merging:" xJ%b<y{@  
    For Each curFile In fList \VPU)  
        Print Chr(9) & curFile g{l;v  
    Next dW!T.S
 
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. -BACdX  
    Dim nameArray() As String, sampName As String 1kl4X3q6  
    nameArray = Split(fList(0)," 0-0.txt") g<KBsz!{  
    sampName  = nameArray(0) L4SFu.J'  
    Print "" [m!\ZK  
    Print "Sample name: " & Chr(9) & sampName 1h]Dc(Oc#=  
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    'Open an output file and write the FRED header data t ba%L  
    Dim outFile As String XXmtpM8  
    outFile = cDir & sampName & "_FRED.txt" nb22bXt  
    Open outFile For Output As #1 I2|iqbX40Q  
    Print #1, "type bsdf_data" H@__%KBw  
    Print #1, "format angles=deg bsdf=value scale=1" 4jis\W}%L3  
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    'Loop the file list, skip the two header lines and write the remaining data to file suPQlU>2sj  
    Dim lineArray() As String, curLine As Long tTF/$`Q#*  
    For Each curFile In fList tb&{[|O^  
        Print "Merging data from file " & curFile kYxn5+~  
        ReadFile( cDir & curFile, lineArray ) >F,~QHcz  
        For curLine = 2 To UBound(lineArray) |??uVA)\X  
            Print #1, lineArray(curLine) ]Rnr>_>x;  
        Next <+sv
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    Next ]t7<$L   
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    'Close the output file lh~!cOm\=E  
    Close #1 T\8|Q@  
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    Print "Finished merging RPC data for sample " & sampName GRO[&;d`  
    Print "FRED formatted data file: " & Chr(9) & outFile Gt\
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End Sub 04:^<n+{  
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'Utility function to read the contents of a file into an array of strings. "+&|$*  
Function ReadFile(ByVal fileName As String, _ \|DcWH1  
                  ByRef lineArray() As String) As Long D19uI&U4  
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    ReadFile = -1 FB6`2E%o  
    Dim oFSO As Object <G\q/!@_  
    Set oFSO = CreateObject("Scripting.FileSystemObject") #<4h Y7/  
    Erase lineArray h3>/..l  
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    Dim fid As Long t%q@W,2J  
    If oFSO.fileexists( fileName ) Then n/S1Hae`  
        fid = FreeFile() gAgzM?A1(  
        Open fileName For Input As fid J'b*^K  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) WJ=eV8Uk  
        Close fid {Z1j>h$  
    End If m}Kn!21  
    Set oFSO = Nothing Y%|f<C)lx2  
    Return UBound( lineArray ) 2m[z4V@`  
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End Function gI'4g ZH  
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Sub GetFileList( ByVal in_dir As String, _ MY4cMMjp~  
                 ByRef in_flist() As String ) /*`u(d2g  
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    'Redimension the file list array V ;1$FNR   
    Erase in_flist +Q}Y?([  
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    'Tracks how many files are found *s S7^OZ*  
    Dim fCount As Long *Jmy:C<>  
    fCount = 0 R4]t
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    'Recurse directory and search for text files |.)oV;9  
    Dim f As String 2"c$#N  
    f = Dir$(in_dir & "*.txt") F%+/j5~^  
    While f <> "" $cSrT)u:  
        ReDim Preserve in_flist(fCount) \=XAl >}\  
        in_flist(fCount) = f }tua0{N:z  
        fCount += 1 SwV
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        f = Dir$() (
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    Wend >ys>Q)  
    ReDim Preserve in_flist(fCount-1)
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End Sub @vCPX=c