[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： R*"zLJ
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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。 $+ \JT/eG9  
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背景： ECOzquvM  
Thorlabs和RPC Photonics联手共同推出的新型漫射体及光束整形技术，可以解决其他技术的不足，大大改善了诸如光刻系统、有效固态照明，显示，背光，显示亮度增强和投影屏等大多数应用的性能。这项我们称之为工程漫射体（Engineered DiffusersTM）的新概念，与其他技术有许多不同。与诸如磨砂玻璃、乳色玻璃和全息元件等随机漫射体截然不同，工程漫射体要求对于每个散射中心，通常为微透镜单元，都进行控制。例如全息漫射体可以视为一组随机排列的透镜，但是通过全息曝光形成的类透镜效果只能通过静态方式进行控制：而无法单独操控每个微透镜单元，这也帮助解释了全息漫射体无法控制光的分布和轮廓。另一方面，在工程漫射体中，每个微透镜单元形成漫射体，由其凹形纵断面和在阵列中的位置所确定。同时，为了确保漫射体不受输入光束变化的影响，并且不产生衍射效果，微透镜单元的分布是随机的，根据产生相应的光束形状函数所选取的概率分布函数来确定。因此，工程漫射体同时保留了随机与确定性漫射体的优点，从而实现高性能的光束整形功能。 BfvvJh_  
FRED是美国Photon Engineering 公司开发的光学工程仿真软件，其在杂散光分析中独特的算法、高效的准确性，使其与其它同类产品相比更具优势。本案例我们重点讲述如何由RPC Photonics的BSDF数据转为FRED可识别的散射数据。 j&?@:Zg v  
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步骤 _`]YWvh  
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1、 在http://www.rpcphotonics.com/bsdf-data-optical-diffusers/下载并解压BSDF数据到某一文件夹下，选择“Raw data”文件。 {Pi]i?  
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2、 将     http://fred-kb.photonengr.com/wp-content/uploads/sites/2/2015/06/constructRpcScatterFile.frs脚本文件放在步骤1中的文件下。（脚本代码放在了本文的最后） \H?r[]*c%  
3、 打开FRED并运行脚本文件，会输出如下“<SAMPLE>_FRED.txt”格式，<SAMPLE>即为RPC Photonics散射片数据集 ~p/1 9/  
例如下所示： n ^C"v6X  
Sample name:  EDF-C1-56 pL'+sW  
Merging data from file EDF-C1-56 0-0.txt i\k>2df  
Finished merging RPC data for sample EDF-C1-56 8z"*CJ@  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt l:VcV  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 jTz~ V&^  
a. 创建一个新的散射库 *p%=u>?&  
b. 散射模型命名 6SD9lgF*-  
c. 改变散射模型为“Tabulated BSDF”. RC]-9gd3Q  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） "f`{4p0v  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 TzY[-YlvF  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， (ft$ R?  
g. 点击OK [[0u|`T/  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 d#3
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脚本代码： nJo6;_MI!  
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'#Language "WWB-COM" DlbNW& V  
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Option Explicit kC-OZVoO  
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Sub Main PzDekyl  
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    'Cleanup Tf?|*P  
    ClearOutputWindow() UgZuEfEGve  
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    Print "Merging RPC Photonics BSDF Data Files" G$$y\e$  
    SetTextColor(255,0,0) 3rw<#t;v  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." <2{-ey]  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." loFApBD=$^  
    SetTextColor(0,0,0) 1|Z!8:&pj  
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    'Current directory of this script (should be the same as the text files being merged) "_T8Km008  
    Dim cDir As String |.Y}2>{  
    cDir = MacroDir$ & "\" &C=[D_h  
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    'Array which will be populated with the list of files to be merged i_6 Y
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    Dim fList() As String, curFile As String f& >[$zh  
    GetFileList( cDir, fList ) hV]]%zwR+  
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    Print "" xF8^#J6>  
    Print "Files found for merging:" gG6j>%y  
    For Each curFile In fList &!5S'J%  
        Print Chr(9) & curFile m3E`kW|  
    Next hMvLx>q3)  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. qt!0#z8  
    Dim nameArray() As String, sampName As String ]3iQpL  
    nameArray = Split(fList(0)," 0-0.txt") G :JQ_w  
    sampName  = nameArray(0) $,9A?'  
    Print "" ^J-\s_)"  
    Print "Sample name: " & Chr(9) & sampName iy\ 6e k1  
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    'Open an output file and write the FRED header data n6]8W^g  
    Dim outFile As String (Ld,<!eN0  
    outFile = cDir & sampName & "_FRED.txt"
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    Open outFile For Output As #1 p`-Oz]  
    Print #1, "type bsdf_data" aBonq]W  
    Print #1, "format angles=deg bsdf=value scale=1" sV`!4 u7%}  
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    'Loop the file list, skip the two header lines and write the remaining data to file C=>IJ'G  
    Dim lineArray() As String, curLine As Long -\V!f6Q  
    For Each curFile In fList 84}Pu%  
        Print "Merging data from file " & curFile TKBW2  
        ReadFile( cDir & curFile, lineArray ) $)6%LG_@  
        For curLine = 2 To UBound(lineArray) Qaeg3f3F3  
            Print #1, lineArray(curLine) 7lH3)9G;  
        Next kMP3PS  
    Next 3q*p#l~  
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    'Close the output file nqMXE82  
    Close #1 1rLK1X  
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    Print "Finished merging RPC data for sample " & sampName +zf[Im%E  
    Print "FRED formatted data file: " & Chr(9) & outFile iu+r=sp  
End Sub (764-iv(  
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'Utility function to read the contents of a file into an array of strings. bs9X4n5  
Function ReadFile(ByVal fileName As String, _ 6(0ME$  
                  ByRef lineArray() As String) As Long K*[`s'Ip-  
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    ReadFile = -1 ]]^eIjg>a6  
    Dim oFSO As Object "F+m}GJ=a  
    Set oFSO = CreateObject("Scripting.FileSystemObject") d,d ohi  
    Erase lineArray eN{ewn#0.  
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    Dim fid As Long xg8$ <Ut  
    If oFSO.fileexists( fileName ) Then 1@W*fVn  
        fid = FreeFile() D@ 4sq^|2  
        Open fileName For Input As fid la}Xo0nq0+  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) ;xxu,  
        Close fid dn}'B%  
    End If >#Ue`)d`aY  
    Set oFSO = Nothing !}pvrBS  
    Return UBound( lineArray ) @D@_PA)e(  
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End Function eOUv#F  
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Sub GetFileList( ByVal in_dir As String, _ AREpZ2GiU  
                 ByRef in_flist() As String ) fx3oA}  
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    'Redimension the file list array 1 ` ={**  
    Erase in_flist M>_ U9g  
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    'Tracks how many files are found @h)Z8so  
    Dim fCount As Long 3K{G=WE$  
    fCount = 0 GA+#'R  
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    'Recurse directory and search for text files h= Mmd  
    Dim f As String 9L7jYy=A#  
    f = Dir$(in_dir & "*.txt") %s*F~E  
    While f <> "" 4IGn,D^  
        ReDim Preserve in_flist(fCount) "l[ c/q[  
        in_flist(fCount) = f -ztgi
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        fCount += 1 XkRPD  
        f = Dir$() U]}f]GK  
    Wend h"ZR`?h  
    ReDim Preserve in_flist(fCount-1) bBg=X}9  
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End Sub nv'YtmR