[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： ]}b  
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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。 T$u
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背景： "!vY{9,  
Thorlabs和RPC Photonics联手共同推出的新型漫射体及光束整形技术，可以解决其他技术的不足，大大改善了诸如光刻系统、有效固态照明，显示，背光，显示亮度增强和投影屏等大多数应用的性能。这项我们称之为工程漫射体（Engineered DiffusersTM）的新概念，与其他技术有许多不同。与诸如磨砂玻璃、乳色玻璃和全息元件等随机漫射体截然不同，工程漫射体要求对于每个散射中心，通常为微透镜单元，都进行控制。例如全息漫射体可以视为一组随机排列的透镜，但是通过全息曝光形成的类透镜效果只能通过静态方式进行控制：而无法单独操控每个微透镜单元，这也帮助解释了全息漫射体无法控制光的分布和轮廓。另一方面，在工程漫射体中，每个微透镜单元形成漫射体，由其凹形纵断面和在阵列中的位置所确定。同时，为了确保漫射体不受输入光束变化的影响，并且不产生衍射效果，微透镜单元的分布是随机的，根据产生相应的光束形状函数所选取的概率分布函数来确定。因此，工程漫射体同时保留了随机与确定性漫射体的优点，从而实现高性能的光束整形功能。 /YZMP'v  
FRED是美国Photon Engineering 公司开发的光学工程仿真软件，其在杂散光分析中独特的算法、高效的准确性，使其与其它同类产品相比更具优势。本案例我们重点讲述如何由RPC Photonics的BSDF数据转为FRED可识别的散射数据。 8~Zw"  
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步骤 tc`3-goX  
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1、 在http://www.rpcphotonics.com/bsdf-data-optical-diffusers/下载并解压BSDF数据到某一文件夹下，选择“Raw data”文件。 7:LEf"vRZ  
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2、 将     http://fred-kb.photonengr.com/wp-content/uploads/sites/2/2015/06/constructRpcScatterFile.frs脚本文件放在步骤1中的文件下。（脚本代码放在了本文的最后） T8g\_m  
3、 打开FRED并运行脚本文件，会输出如下“<SAMPLE>_FRED.txt”格式，<SAMPLE>即为RPC Photonics散射片数据集 .+XK>jl+  
例如下所示： /hqn>t  
Sample name:  EDF-C1-56 =C,DR4xh  
Merging data from file EDF-C1-56 0-0.txt o[KZm17  
Finished merging RPC data for sample EDF-C1-56 y[l{ UBue:  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt 9jf9u0  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 1QA/ !2E  
a. 创建一个新的散射库 0!YVRit\N  
b. 散射模型命名 u(1m#xr8$  
c. 改变散射模型为“Tabulated BSDF”. Jy}~ZY  
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 ） 9[VYd '  
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。 3t+{
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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， m_Ed[h/I  
g. 点击OK q j21#q .  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 c3l(,5DtH  
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脚本代码： ?K pDEH~\  
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'#Language "WWB-COM" Eu&$Rq}  
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Option Explicit `_)9eGQ  
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Sub Main U3B&3K} ~  
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    'Cleanup ` ~m/  
    ClearOutputWindow() *jc >?)k  
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    Print "Merging RPC Photonics BSDF Data Files" Gev\bQa  
    SetTextColor(255,0,0) |Tmug X7  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." .4E24FB[f?  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." ZhCz]z~tj6  
    SetTextColor(0,0,0) mz1m^p)~{  
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    'Current directory of this script (should be the same as the text files being merged) r]xN&Ne5Q  
    Dim cDir As String xzY/$?  
    cDir = MacroDir$ & "\" S6bYd`  
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    'Array which will be populated with the list of files to be merged sx+k V A  
    Dim fList() As String, curFile As String <astIu Au  
    GetFileList( cDir, fList ) ~2hzyEh  
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    Print "" -tWxBGSa@  
    Print "Files found for merging:" 1r.2bL*~jw  
    For Each curFile In fList r%=a:GdAg  
        Print Chr(9) & curFile -}T7F+  
    Next 1S(oi  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. Gl{'a
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    Dim nameArray() As String, sampName As String YG*<jKcX  
    nameArray = Split(fList(0)," 0-0.txt") n)a/pO_  
    sampName  = nameArray(0) )ZLj2H<  
    Print "" VWdTnu  
    Print "Sample name: " & Chr(9) & sampName fuHNsrNlm  
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    'Open an output file and write the FRED header data dMjQV&  
    Dim outFile As String Vo{ ~D:)  
    outFile = cDir & sampName & "_FRED.txt" ) xV>Va8)  
    Open outFile For Output As #1 $Nvox<d0  
    Print #1, "type bsdf_data" +7WpJ;C4  
    Print #1, "format angles=deg bsdf=value scale=1" `r=^{Y  
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    'Loop the file list, skip the two header lines and write the remaining data to file qrOesSdc  
    Dim lineArray() As String, curLine As Long N!?~Dgw  
    For Each curFile In fList 8TH;6-RT  
        Print "Merging data from file " & curFile ;A"i.:ZT  
        ReadFile( cDir & curFile, lineArray ) !Y UT*  
        For curLine = 2 To UBound(lineArray) _z]v;Q  
            Print #1, lineArray(curLine)  K\ pZ  
        Next `_neYT  
    Next m|?1HCRXRI  
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    'Close the output file E<B/5g!  
    Close #1 ,{iMF (Nj  
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    Print "Finished merging RPC data for sample " & sampName B[w.8e5  
    Print "FRED formatted data file: " & Chr(9) & outFile <uoVGV5N  
End Sub rjfWty%6pX  
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'Utility function to read the contents of a file into an array of strings. e5FF'~A%]  
Function ReadFile(ByVal fileName As String, _ )<'2 vpz  
                  ByRef lineArray() As String) As Long }|=Fnyj  
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    ReadFile = -1 3M[d6@a  
    Dim oFSO As Object _ !"[Zr  
    Set oFSO = CreateObject("Scripting.FileSystemObject") h>xB"E|.  
    Erase lineArray HCktgL:E=  
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    Dim fid As Long /NPx9cLW^  
    If oFSO.fileexists( fileName ) Then  W>x.*K  
        fid = FreeFile() Bq4@I_b  
        Open fileName For Input As fid Q}lY1LT`  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) 4|jPr J  
        Close fid Ttb?x<)+8  
    End If ~:C`e4  
    Set oFSO = Nothing Y.52`s6F  
    Return UBound( lineArray ) n*AN/LB
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End Function 0"sZP\<p  
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Sub GetFileList( ByVal in_dir As String, _ n%vmo f  
                 ByRef in_flist() As String ) %&'[? LXD  
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    'Redimension the file list array r5lPO*?Df  
    Erase in_flist (LVzE_`  
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    'Tracks how many files are found "[_gRe*2  
    Dim fCount As Long dt=M#+g  
    fCount = 0 PGTjOkx  
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    'Recurse directory and search for text files uqBVKE  
    Dim f As String wUS w9xg  
    f = Dir$(in_dir & "*.txt") FYg{IKg  
    While f <> "" T}'*Gry  
        ReDim Preserve in_flist(fCount) [].euDrX  
        in_flist(fCount) = f
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        fCount += 1 w0.;86<MV  
        f = Dir$() L1SZutWD?  
    Wend o8A(Cg}  
    ReDim Preserve in_flist(fCount-1) "GxQ9=Z  
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End Sub )4GCL(&