[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： @D=%J!!*  
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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。 :g' '
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背景： K/*"U*9Kv  
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。 ' (XB|5  
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。 #"?pY5 ("  
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步骤 =<m!%/I  
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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。 GG<0k\RN  
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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） +F8K%.Q_  
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 S@S4<R1{\  
例如下所示： -y|']I^ &  
Sample name:  EDF-C1-56 ^Go,HiB  
Merging data from file EDF-C1-56 0-0.txt @9n|5.i  
Finished merging RPC data for sample EDF-C1-56 T0"nzukd  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt v_pe=LC{-e  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 /]j
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a. 创建一个新的散射库 )?{!7/H F@  
b. 散射模型命名 rPyjr(I"_  
c. 改变散射模型为“Tabulated BSDF”. <uJ {>~  
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 ） e
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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。 &z5?]`ALu  
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， `GY3H3B  
g. 点击OK XTk :lzFH  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 0*tnJB  
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脚本代码： w+)wrJTtm  
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'#Language "WWB-COM" \lQI;b;$  
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Option Explicit a9.255  
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Sub Main X[H.t$w5A  
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    'Cleanup WQ.{Ag?1  
    ClearOutputWindow() km5gO|V>m  
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    Print "Merging RPC Photonics BSDF Data Files" 6SE^+@jR  
    SetTextColor(255,0,0) a73VDQr I  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." {jQLr7'  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." s_RK x)w@  
    SetTextColor(0,0,0)  4q7H  
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    'Current directory of this script (should be the same as the text files being merged) ^c(r4#}$"  
    Dim cDir As String }qoId3iY!7  
    cDir = MacroDir$ & "\" nvLdgu4P>  
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    'Array which will be populated with the list of files to be merged [A{o"zY  
    Dim fList() As String, curFile As String xoj,>[7 D  
    GetFileList( cDir, fList ) eFS$;3FP1  
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    Print "" yHC[8l8%  
    Print "Files found for merging:"
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    For Each curFile In fList (G} }h  
        Print Chr(9) & curFile T+EwC)Ll  
    Next X(Mpg[,N"  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. Vj1V;d
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    Dim nameArray() As String, sampName As String 7G;1n0m-T  
    nameArray = Split(fList(0)," 0-0.txt") I0Allw[  
    sampName  = nameArray(0) >eo[)Y  
    Print "" bx{njo1Mr  
    Print "Sample name: " & Chr(9) & sampName >@cBDS<6R  
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    'Open an output file and write the FRED header data $|&<cenMT  
    Dim outFile As String cpw=2vnD  
    outFile = cDir & sampName & "_FRED.txt" _=`DzudE  
    Open outFile For Output As #1 WHOy\j},V  
    Print #1, "type bsdf_data" "fhQ{b$i  
    Print #1, "format angles=deg bsdf=value scale=1" z)v o  
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    'Loop the file list, skip the two header lines and write the remaining data to file m;rr7{7X  
    Dim lineArray() As String, curLine As Long !s/qqq:g  
    For Each curFile In fList L>g6 9D!  
        Print "Merging data from file " & curFile )CE]s)6+2  
        ReadFile( cDir & curFile, lineArray ) 5bXpj86mY  
        For curLine = 2 To UBound(lineArray) LH+Bu%s  
            Print #1, lineArray(curLine) >
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        Next L >"O[@  
    Next ??P\v0E  
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    'Close the output file 5Uy*^C7M^  
    Close #1 .{?;#Cdn  
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    Print "Finished merging RPC data for sample " & sampName Qx|HvT2P  
    Print "FRED formatted data file: " & Chr(9) & outFile *H
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End Sub pp1Kor  
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'Utility function to read the contents of a file into an array of strings. Ah@e9`_r  
Function ReadFile(ByVal fileName As String, _ U&Atgv  
                  ByRef lineArray() As String) As Long B=^M& {  
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    ReadFile = -1 K8-1?-W  
    Dim oFSO As Object eNi#% ?=WB  
    Set oFSO = CreateObject("Scripting.FileSystemObject") >Je$WE3  
    Erase lineArray hJ[keaO  
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    Dim fid As Long 6(htpT%J  
    If oFSO.fileexists( fileName ) Then R)$]r>YZF  
        fid = FreeFile() (6mw@gzr  
        Open fileName For Input As fid h:C:opa-=  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) c2
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        Close fid ~l] w=[ z  
    End If JgP%4)]LV  
    Set oFSO = Nothing =MM+(mD  
    Return UBound( lineArray ) '-I\G6w9  
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End Function 1|>vk+;1h  
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Sub GetFileList( ByVal in_dir As String, _ gN(kRhp  
                 ByRef in_flist() As String ) hR2 R  
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    'Redimension the file list array IUh9skW5  
    Erase in_flist ,aP5)ZN-  
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    'Tracks how many files are found mRyf+O[  
    Dim fCount As Long .8ikcs  
    fCount = 0
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    'Recurse directory and search for text files 1B&XM^>/  
    Dim f As String &,Loqr  
    f = Dir$(in_dir & "*.txt") .-MJ5d:  
    While f <> "" $I#~<bW,  
        ReDim Preserve in_flist(fCount) 32anmVnf  
        in_flist(fCount) = f ?aBAmyxm  
        fCount += 1 ngd4PN>{4  
        f = Dir$() ^c.pvC"4j
 
    Wend ^e =xEZD  
    ReDim Preserve in_flist(fCount-1) |d6/
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End Sub !{(crfXB