[分享]RPC Photonics扩散片BSDF [复制链接]

摘要： qssK0!-  
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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。 xf:|lQf  
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背景： \$,;@H5I^  
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。 VB+_ kR6Zv  
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。 oBPm^ob4  
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步骤 `Z@qWB<  

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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。 eN TKX  
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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） @Rqn&tA8  
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 0n?^I>j  
例如下所示： z_$F)*PL  
Sample name:  EDF-C1-56 9$R}GK  
Merging data from file EDF-C1-56 0-0.txt ^7`gf  
Finished merging RPC data for sample EDF-C1-56 +4]f6Zz({  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt Q\le3KB
 
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 ^"J)^3j<  
a. 创建一个新的散射库 N/B-u
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b. 散射模型命名 Cj6$W
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c. 改变散射模型为“Tabulated BSDF”. 5.U|CL  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） =kW7|c5Z  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 [Al}GM  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， `jGG^w3  
g. 点击OK 6l(HD([_p  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 s";9G^:  
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脚本代码： Yc>.P  
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'#Language "WWB-COM" t "[2^2G  
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Option Explicit ",45p@  
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Sub Main 5k<0>6;XH  
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    'Cleanup (5=B^9{R  
    ClearOutputWindow() z dUSmb  
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    Print "Merging RPC Photonics BSDF Data Files" SOJkeN  
    SetTextColor(255,0,0) !X<dN..  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." J+Zp<Wu-  
    Print "Note: Do not run this script multiple times without deleting the output file between executions."
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    SetTextColor(0,0,0) hyC]{E  
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    'Current directory of this script (should be the same as the text files being merged) 5wm(gF_t  
    Dim cDir As String X:OUu;  
    cDir = MacroDir$ & "\" n4Q ^  
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    'Array which will be populated with the list of files to be merged KyRcZ"  
    Dim fList() As String, curFile As String _h P7hhR  
    GetFileList( cDir, fList ) d01]5'f?o  
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    Print "" 2j-^F  
    Print "Files found for merging:" pn aSOyR  
    For Each curFile In fList F+m;y  
        Print Chr(9) & curFile 7SJtW`~  
    Next :z%q09.)  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. C.?~D*Q  
    Dim nameArray() As String, sampName As String '0jn|9l58  
    nameArray = Split(fList(0)," 0-0.txt") /n8\^4{fP{  
    sampName  = nameArray(0) (Ujry =f  
    Print "" '>#8 F.  
    Print "Sample name: " & Chr(9) & sampName 2X@"#wIg  
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    'Open an output file and write the FRED header data eDS,}Z'  
    Dim outFile As String (cm8x  
    outFile = cDir & sampName & "_FRED.txt" h~u|v[@{J  
    Open outFile For Output As #1 $VUX?ii$7=  
    Print #1, "type bsdf_data" !4(QeV-=  
    Print #1, "format angles=deg bsdf=value scale=1" ix_&<?8  
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    'Loop the file list, skip the two header lines and write the remaining data to file Q?{^8?7  
    Dim lineArray() As String, curLine As Long YaAOP'p  
    For Each curFile In fList ^_G@a,  
        Print "Merging data from file " & curFile =nE^zY2m%  
        ReadFile( cDir & curFile, lineArray ) d2X?^  
        For curLine = 2 To UBound(lineArray) wYN/ }>M  
            Print #1, lineArray(curLine) t`E e/L%  
        Next ^.@F1k  
    Next U'0e<IcY  
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    'Close the output file :r}C&3  
    Close #1 w7QYWf'  
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    Print "Finished merging RPC data for sample " & sampName zx;~sUR;  
    Print "FRED formatted data file: " & Chr(9) & outFile ^D A<=C-[!  
End Sub 9
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'Utility function to read the contents of a file into an array of strings. !p{
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Function ReadFile(ByVal fileName As String, _ cng166}1A  
                  ByRef lineArray() As String) As Long b>L?0p$ej  
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    ReadFile = -1 aBWA hn  
    Dim oFSO As Object w7b\?]}@  
    Set oFSO = CreateObject("Scripting.FileSystemObject") CRPE:7,D  
    Erase lineArray Y
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    Dim fid As Long EjP9/VG@=  
    If oFSO.fileexists( fileName ) Then !
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        fid = FreeFile() R0YWe  
        Open fileName For Input As fid )F,z pGG  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) 'C) v?!19  
        Close fid arN=OB  
    End If v:]z-zU  
    Set oFSO = Nothing nfksi``Vq  
    Return UBound( lineArray ) )8;At'q}  
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End Function 1x^Vv;K  
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Sub GetFileList( ByVal in_dir As String, _ i7%`}t  
                 ByRef in_flist() As String ) +P%k@w#<Z  
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    'Redimension the file list array O2"5\@HfE  
    Erase in_flist $0|`h)&  
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    'Tracks how many files are found 8yk4#CZ  
    Dim fCount As Long o2!wz8  
    fCount = 0 a] 7nK+N  
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    'Recurse directory and search for text files U<<XeSp  
    Dim f As String bD.KD)5  
    f = Dir$(in_dir & "*.txt") HJJ;gTj  
    While f <> "" 06]"{2  
        ReDim Preserve in_flist(fCount) UT0}Ce>e  
        in_flist(fCount) = f c&C*'c-r  
        fCount += 1 Sg*+!  
        f = Dir$() K%1`LT5:~  
    Wend 3%)@c P:
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    ReDim Preserve in_flist(fCount-1) &z@}9U*6b  
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End Sub DMlr%)@{  
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