[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： T%#P??k  
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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。 >" 8j{s  
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背景： G:s:NXy^  
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。 r
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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。 i(;u6Rk  

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步骤 L|'ME| '  
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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。 !d@`r1t  
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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） oYM3$.{E  
3、 打开FRED并运行脚本文件，会输出如下“<SAMPLE>_FRED.txt”格式，<SAMPLE>即为RPC Photonics散射片数据集 Hjkgy%N  
例如下所示： W3j|%  
Sample name:  EDF-C1-56 zt%Fvn4/pF  
Merging data from file EDF-C1-56 0-0.txt j %0_!*#3  
Finished merging RPC data for sample EDF-C1-56 c<x6_H6[8  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt lR3^&d72?  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 S.4YC>E  
a. 创建一个新的散射库 uk/+ i`=  
b. 散射模型命名 V2* |j8|  
c. 改变散射模型为“Tabulated BSDF”. <plR<iI.  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） =KD*+.'\/  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 (6^k;j  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， /pN2
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g. 点击OK zQ_[wM-  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 T+"y8#:  
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脚本代码： e
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'#Language "WWB-COM" '$
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Option Explicit H)+kN'J  
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Sub Main I]
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    'Cleanup EKD>c$T^  
    ClearOutputWindow() YTit=4|  
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    Print "Merging RPC Photonics BSDF Data Files" N^N?!I  
    SetTextColor(255,0,0) k| o,gcU  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." 7T Bo*-!  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." { "c,P:S]  
    SetTextColor(0,0,0) xxn&{\ ?  
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    'Current directory of this script (should be the same as the text files being merged) eP?|U.on  
    Dim cDir As String #^V"=RbD  
    cDir = MacroDir$ & "\" 1w^[Eno$$  
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    'Array which will be populated with the list of files to be merged Q1[s{,  
    Dim fList() As String, curFile As String 1ouTZ'c?  
    GetFileList( cDir, fList ) Q(3x
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    Print "" es]m 6A  
    Print "Files found for merging:" &O)mPnx`  
    For Each curFile In fList Fgk/Ph3r  
        Print Chr(9) & curFile 0xcqX!(  
    Next 7mNskb|  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. G#v7-&Yl6  
    Dim nameArray() As String, sampName As String 6u}NI!he  
    nameArray = Split(fList(0)," 0-0.txt") ?J?!%Mw  
    sampName  = nameArray(0) <
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    Print "" 0=DawJ9  
    Print "Sample name: " & Chr(9) & sampName 7
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    'Open an output file and write the FRED header data bwFc>{Wo5  
    Dim outFile As String +pm8;&  
    outFile = cDir & sampName & "_FRED.txt" w>s  
    Open outFile For Output As #1 rl=_ "sd=  
    Print #1, "type bsdf_data" s qKkTG3  
    Print #1, "format angles=deg bsdf=value scale=1" 4+gA/<  
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    'Loop the file list, skip the two header lines and write the remaining data to file ]Ox.6BKjDP  
    Dim lineArray() As String, curLine As Long ;|y,bo@sJJ  
    For Each curFile In fList .Dmvgi]  
        Print "Merging data from file " & curFile !%@{S8IP.v  
        ReadFile( cDir & curFile, lineArray ) H5{J2M,f  
        For curLine = 2 To UBound(lineArray) /H%pOL6(r  
            Print #1, lineArray(curLine) )%7A. UO)  
        Next HvTQycG  
    Next 0*/~9n-Vl  
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    'Close the output file G#Ow>NJ  
    Close #1 *79<ypKG$  
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    Print "Finished merging RPC data for sample " & sampName V2.K*CpZ7  
    Print "FRED formatted data file: " & Chr(9) & outFile n
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End Sub elN3B91\6r  
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'Utility function to read the contents of a file into an array of strings. uJ$,e5q  
Function ReadFile(ByVal fileName As String, _ {Hv=iVmt  
                  ByRef lineArray() As String) As Long 2H#vA  
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    ReadFile = -1 'Bx7b(xqk  
    Dim oFSO As Object C@-JH\{\T#  
    Set oFSO = CreateObject("Scripting.FileSystemObject") ?H`LrL/k  
    Erase lineArray wSK?mS6  
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    Dim fid As Long c#DTL/8"DO  
    If oFSO.fileexists( fileName ) Then ORoraEK  
        fid = FreeFile() 2,\uY}4  
        Open fileName For Input As fid Ow I?(ruL'  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) J
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        Close fid fomkwN  
    End If 9maw+c!~  
    Set oFSO = Nothing )+G(4eIT  
    Return UBound( lineArray ) '9)@U+yfQ  
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End Function N?XN$hwdZ  
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Sub GetFileList( ByVal in_dir As String, _ UgP5^3F2  
                 ByRef in_flist() As String ) a srkuAS  
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    'Redimension the file list array tv2dyC&a  
    Erase in_flist cg~FW2Q  
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    'Tracks how many files are found "J9+~)e^!  
    Dim fCount As Long sw1XN?O  
    fCount = 0 zM!*r~*k$  
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    'Recurse directory and search for text files Oq("E(z+f  
    Dim f As String T^'i+>F!w  
    f = Dir$(in_dir & "*.txt") ZDf9Npe  
    While f <> "" yZ{YIy~  
        ReDim Preserve in_flist(fCount) O6pjuhMx  
        in_flist(fCount) = f vcmS]$}  
        fCount += 1 YpL}R#  
        f = Dir$() ZBGI_9wZ  
    Wend <3qbgn>}b  
    ReDim Preserve in_flist(fCount-1) E(oNS\4  
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End Sub u-Vn
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