[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： dDu8n+(8 L  
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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。 8}M-b6RV  
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背景： "?*B2*|}`  
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。 oV/:T\Qn=  
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。 ;B^ 9sr  
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步骤 YD9|2S!G  
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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。 "g
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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） G1 K@Ir<  
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 g+j\wvx0  
例如下所示： 1b=,lm  
Sample name:  EDF-C1-56 SuR+
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Merging data from file EDF-C1-56 0-0.txt ' Ig:-
 
Finished merging RPC data for sample EDF-C1-56 /Moyn"Kj{  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt sC'PtFK8z  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 oA*88c+{f  
a. 创建一个新的散射库 >qy$W4  
b. 散射模型命名 Mdw"^x$7  
c. 改变散射模型为“Tabulated BSDF”. eK
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d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） G_QV'zQ  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 xeB-fy)5+  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， ]>/oo
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g. 点击OK Fy*t[>  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 GU0[K#%  
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脚本代码： eemC;JV%  
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'#Language "WWB-COM" XI'.L ~  
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Option Explicit *L&|4|BF2  
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Sub Main ;uho.)%N`F  
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    'Cleanup >~l^E!<i-u  
    ClearOutputWindow() 7\AoMk}  
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    Print "Merging RPC Photonics BSDF Data Files" V 7oE\cxr  
    SetTextColor(255,0,0) >l b9j>  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." sis1Dh9:  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." *`40
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    SetTextColor(0,0,0) Obx!>mI^6  
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    'Current directory of this script (should be the same as the text files being merged) 2c'<rkA  
    Dim cDir As String '};mBW4z  
    cDir = MacroDir$ & "\" k5|GN Y6a  
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    'Array which will be populated with the list of files to be merged gg.lajX  
    Dim fList() As String, curFile As String BZa`:ah~x  
    GetFileList( cDir, fList ) -bgj<4R$p  
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    Print "" b w!  
    Print "Files found for merging:" R].xT-1  
    For Each curFile In fList Jsa;pG=3&  
        Print Chr(9) & curFile OYfRtfE  
    Next u}?|d8$h\  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. q26qY5D  
    Dim nameArray() As String, sampName As String NE><(02qW  
    nameArray = Split(fList(0)," 0-0.txt") Eb8~i_B-  
    sampName  = nameArray(0) !TN)6e7`  
    Print "" Ekn3ODz,  
    Print "Sample name: " & Chr(9) & sampName sD9OV6^{?K  
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    'Open an output file and write the FRED header data On(.(7sNc  
    Dim outFile As String Q yhu=_&  
    outFile = cDir & sampName & "_FRED.txt" Rw<O%i5/d  
    Open outFile For Output As #1 ~ %Ij5PD  
    Print #1, "type bsdf_data" zhe~kI  
    Print #1, "format angles=deg bsdf=value scale=1" xJin%:O  
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    'Loop the file list, skip the two header lines and write the remaining data to file n0)y|B#  
    Dim lineArray() As String, curLine As Long im9Pjb%  
    For Each curFile In fList e35")z~  
        Print "Merging data from file " & curFile L/)eNZ  
        ReadFile( cDir & curFile, lineArray ) E;YD5^B  
        For curLine = 2 To UBound(lineArray) P=a&
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            Print #1, lineArray(curLine) L=5Y^f'aU  
        Next BO+to.  
    Next %"ehZd0r  
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    'Close the output file <
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    Close #1 7
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    Print "Finished merging RPC data for sample " & sampName `,Fc271`  
    Print "FRED formatted data file: " & Chr(9) & outFile EvT"+;9/p  
End Sub O' Mma5  
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'Utility function to read the contents of a file into an array of strings. 0S\HO<~k  
Function ReadFile(ByVal fileName As String, _ \okvL2:!  
                  ByRef lineArray() As String) As Long Z^.qX\<M  
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    ReadFile = -1 9Qq%Fw_  
    Dim oFSO As Object bV:MOj^  
    Set oFSO = CreateObject("Scripting.FileSystemObject") g(R!M0hdF  
    Erase lineArray [7l5p(=  
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    Dim fid As Long JmuoYlf|  
    If oFSO.fileexists( fileName ) Then <!-#]6  
        fid = FreeFile() }:\e"Bfv  
        Open fileName For Input As fid uFG ;AY|  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) ~7H?tp.Dw  
        Close fid PI)uBA;  
    End If C9j5Pd5q1L  
    Set oFSO = Nothing jF{)2|5  
    Return UBound( lineArray ) zomg$@j  
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End Function ,]4.|A_[Rq  
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Sub GetFileList( ByVal in_dir As String, _ {sUc2vR  
                 ByRef in_flist() As String ) xw3A|Aj?r  
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    'Redimension the file list array ah!fQLMH  
    Erase in_flist `n
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    'Tracks how many files are found *jl_,0g]  
    Dim fCount As Long R/&C}6Gn  
    fCount = 0 :Ek3]`q#  
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    'Recurse directory and search for text files mZ.E;X& ,*  
    Dim f As String nVk]Qe  
    f = Dir$(in_dir & "*.txt") ,]=Qgn  
    While f <> "" TzrU |D?  
        ReDim Preserve in_flist(fCount) X6oY-4O  
        in_flist(fCount) = f *4 Kc "M  
        fCount += 1 !e0/1 j=  
        f = Dir$() ;W!hl<``d*  
    Wend LESF*rh=  
    ReDim Preserve in_flist(fCount-1) tUs{/Je  
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End Sub s`,.&