[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： J fsCkS  
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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。 li/O&@g`  
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背景： BMFpkK9|  
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。 {wA@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。 Fp@eb8Pl  
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步骤 b%|%Rek8  
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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。 yDy3;*lE  
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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） 9O}YtX2
 
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 F Fg0}  
例如下所示： siyJjE)}w  
Sample name:  EDF-C1-56 \Sm.]=br  
Merging data from file EDF-C1-56 0-0.txt mjy%xzVr6^  
Finished merging RPC data for sample EDF-C1-56 yKfRwO[j  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt S~Nx;sB  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 z KJ6j]m  
a. 创建一个新的散射库 2psI\7UjA]  
b. 散射模型命名 LuQ=i`eXx  
c. 改变散射模型为“Tabulated BSDF”. /i^b;?/1  
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 ） ??1V__w  
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。 7NJ1cQ-}t  
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， f}XUxIQ-<  
g. 点击OK LZ\}Kgi(!T  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 #a}fI  
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脚本代码： 7%)4cHZ^$?  
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'#Language "WWB-COM" M^g"U`  
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Option Explicit JNX7]j\  
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Sub Main *W#x#0j  
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    'Cleanup w_\niqm<y  
    ClearOutputWindow() ULQ*cW&;?  
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    Print "Merging RPC Photonics BSDF Data Files" 4y)"IOd#|  
    SetTextColor(255,0,0) dwAju:-H  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." S ._9  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." Ij{{Z;o3  
    SetTextColor(0,0,0) &?YQVwsN  
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    'Current directory of this script (should be the same as the text files being merged) Ng+k{vAj  
    Dim cDir As String Hyq|%\A  
    cDir = MacroDir$ & "\" '+'
  
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    'Array which will be populated with the list of files to be merged my*UN_]  
    Dim fList() As String, curFile As String m0un=>{  
    GetFileList( cDir, fList ) 5O*.qp?  
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    Print "" (x?A#o>%  
    Print "Files found for merging:" ?c=l"\^x  
    For Each curFile In fList +2C:]  
        Print Chr(9) & curFile "C}nS=]8m  
    Next wf8vKl#Kfw  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. d!w32Y,.  
    Dim nameArray() As String, sampName As String JJ7-$h'0q  
    nameArray = Split(fList(0)," 0-0.txt") M,cI0i  
    sampName  = nameArray(0) yUEUIPL  
    Print "" mn 8A%6W  
    Print "Sample name: " & Chr(9) & sampName !|Vjv}UO  
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    'Open an output file and write the FRED header data E})PNf;  
    Dim outFile As String m,*t}j0 7  
    outFile = cDir & sampName & "_FRED.txt" iFga==rw  
    Open outFile For Output As #1 i,* DWD+  
    Print #1, "type bsdf_data" vxbO>c  
    Print #1, "format angles=deg bsdf=value scale=1" 183'1Z$KA  
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    'Loop the file list, skip the two header lines and write the remaining data to file }$g5
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    Dim lineArray() As String, curLine As Long % J+'7'g  
    For Each curFile In fList zif()i   
        Print "Merging data from file " & curFile [f- #pew  
        ReadFile( cDir & curFile, lineArray ) 5l{_E:.1  
        For curLine = 2 To UBound(lineArray) ^@L  
            Print #1, lineArray(curLine) rQ~%SUM7  
        Next tEf-BV;\y  
    Next p[g!LD  
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    'Close the output file EeL~`$f  
    Close #1 a=C?fh  
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    Print "Finished merging RPC data for sample " & sampName 6=|Q>[K  
    Print "FRED formatted data file: " & Chr(9) & outFile _K/h/!\n  
End Sub T[ mTA>d  
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'Utility function to read the contents of a file into an array of strings. 3MkF  
Function ReadFile(ByVal fileName As String, _ ^"*r'  
                  ByRef lineArray() As String) As Long ~#) DJ  

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    ReadFile = -1 !aII

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    Dim oFSO As Object #?8'Z/1)  
    Set oFSO = CreateObject("Scripting.FileSystemObject") Pm" ,7  
    Erase lineArray X*d,z~k%*d  
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    Dim fid As Long 7j._3'M=Kc  
    If oFSO.fileexists( fileName ) Then #l{q
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        fid = FreeFile() ]FsPlxk6  
        Open fileName For Input As fid ?vM{9!M  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) ,X9Y/S l  
        Close fid -C.eXR{s  
    End If ' 71D:%p  
    Set oFSO = Nothing TLO-$>h  
    Return UBound( lineArray ) b:W]L3Z8  
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End Function 5b|_?Em7  
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Sub GetFileList( ByVal in_dir As String, _ ) ~ C)4  
                 ByRef in_flist() As String ) `YIpZ rB  
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    'Redimension the file list array ><^A4s  
    Erase in_flist +| Cvv]Tx1  
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    'Tracks how many files are found rK)%n!Z  
    Dim fCount As Long =C5[75z#+  
    fCount = 0 5E}0
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    'Recurse directory and search for text files 8fZ\})t  
    Dim f As String [=..#y!U  
    f = Dir$(in_dir & "*.txt") [wIyW/
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    While f <> "" #YhKAG@|  
        ReDim Preserve in_flist(fCount) PvKe|In(  
        in_flist(fCount) = f =d( 6 )  
        fCount += 1 e|]g?!  
        f = Dir$() P_Po g^  
    Wend Y$Os&t@bu  
    ReDim Preserve in_flist(fCount-1) D`,@EW].  
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End Sub scN}eg:5