[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： c.Hw K\IU  
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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。 7Qd$@ m  
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背景： /Q(boY{  
Thorlabs和RPC Photonics联手共同推出的新型漫射体及光束整形技术，可以解决其他技术的不足，大大改善了诸如光刻系统、有效固态照明，显示，背光，显示亮度增强和投影屏等大多数应用的性能。这项我们称之为工程漫射体（Engineered DiffusersTM）的新概念，与其他技术有许多不同。与诸如磨砂玻璃、乳色玻璃和全息元件等随机漫射体截然不同，工程漫射体要求对于每个散射中心，通常为微透镜单元，都进行控制。例如全息漫射体可以视为一组随机排列的透镜，但是通过全息曝光形成的类透镜效果只能通过静态方式进行控制：而无法单独操控每个微透镜单元，这也帮助解释了全息漫射体无法控制光的分布和轮廓。另一方面，在工程漫射体中，每个微透镜单元形成漫射体，由其凹形纵断面和在阵列中的位置所确定。同时，为了确保漫射体不受输入光束变化的影响，并且不产生衍射效果，微透镜单元的分布是随机的，根据产生相应的光束形状函数所选取的概率分布函数来确定。因此，工程漫射体同时保留了随机与确定性漫射体的优点，从而实现高性能的光束整形功能。 R)JH D7 1  
FRED是美国Photon Engineering 公司开发的光学工程仿真软件，其在杂散光分析中独特的算法、高效的准确性，使其与其它同类产品相比更具优势。本案例我们重点讲述如何由RPC Photonics的BSDF数据转为FRED可识别的散射数据。 ZN$%\,<  
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步骤 Yft [)id  
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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。 TS|Bz2(  
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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） /}~=)QHH  
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 Itr4Pr  
例如下所示： bpZA%{GS  
Sample name:  EDF-C1-56 
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Merging data from file EDF-C1-56 0-0.txt PY7H0\S)  
Finished merging RPC data for sample EDF-C1-56 __9FQ{Ra  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt x6R M)rr  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 e`g+Jf`AT  
a. 创建一个新的散射库 r+C4<-dT  
b. 散射模型命名 XyN " Jr  
c. 改变散射模型为“Tabulated BSDF”. 7ihcjyXB  
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 ） S:j{R^$k  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 9zqo!&  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， UU>+b:  
g. 点击OK v; i4ZSV^A  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 3S+9LOrhY  
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脚本代码： f4P({V  
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'#Language "WWB-COM" #tu>h  
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Option Explicit ph5{i2U0  
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Sub Main J1I,;WGf  
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    'Cleanup q{9 \hEeb  
    ClearOutputWindow() H5Eso*v@  
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    Print "Merging RPC Photonics BSDF Data Files" 4t(/F`  
    SetTextColor(255,0,0) 46NuT]6/4  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." :po6%}hn  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." \_,p@r]Q  
    SetTextColor(0,0,0) -V{"Lzrfug  
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    'Current directory of this script (should be the same as the text files being merged) tIDN~[1  
    Dim cDir As String 7\%JJw6h  
    cDir = MacroDir$ & "\" IXtG 36O  
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    'Array which will be populated with the list of files to be merged 8&8!(\xv  
    Dim fList() As String, curFile As String (CIcM3|9C  
    GetFileList( cDir, fList ) f:+/=MW  
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    Print "" kQbZ!yl>[  
    Print "Files found for merging:" V4jMx[  
    For Each curFile In fList dVB#Np  
        Print Chr(9) & curFile WlQCPC  
    Next v}u]tl$,  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. 6:|;O  
    Dim nameArray() As String, sampName As String +_fFRyu>  
    nameArray = Split(fList(0)," 0-0.txt") 7uc\AhOk6  
    sampName  = nameArray(0) kll!tT-N-  
    Print "" KJQ8Yhq  
    Print "Sample name: " & Chr(9) & sampName lFt!  
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    'Open an output file and write the FRED header data nu+K N,3R"  
    Dim outFile As String `.pEI q^  
    outFile = cDir & sampName & "_FRED.txt" WeRDaG  
    Open outFile For Output As #1 wJ2cAX;"  
    Print #1, "type bsdf_data" &v .S_Ym  
    Print #1, "format angles=deg bsdf=value scale=1" Z(|$[GZP[  
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    'Loop the file list, skip the two header lines and write the remaining data to file jw{N#QDh  
    Dim lineArray() As String, curLine As Long QD!NV*  
    For Each curFile In fList f> Jj5he/  
        Print "Merging data from file " & curFile }nPt[77U_7  
        ReadFile( cDir & curFile, lineArray ) d)-ZL*o  
        For curLine = 2 To UBound(lineArray) 36OQHv;&  
            Print #1, lineArray(curLine) D%o(HS\E  
        Next G3TS?u8Q  
    Next VI4mEq,V  
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    'Close the output file 0=HB!{@  
    Close #1 >xo<i8<Miv  
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    Print "Finished merging RPC data for sample " & sampName QxW+|Gt._  
    Print "FRED formatted data file: " & Chr(9) & outFile *Lrrl  
End Sub A@< !'  

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'Utility function to read the contents of a file into an array of strings. wnd #J `  
Function ReadFile(ByVal fileName As String, _ .B~yI3D`M  
                  ByRef lineArray() As String) As Long p35)K5V  
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    ReadFile = -1 9~Sa7P  
    Dim oFSO As Object el5Pe{j'  
    Set oFSO = CreateObject("Scripting.FileSystemObject") @uyQH c,V  
    Erase lineArray :MF`q.:X  
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    Dim fid As Long &_Cc  
    If oFSO.fileexists( fileName ) Then ,YM=?No  
        fid = FreeFile() gWU#NRRc  
        Open fileName For Input As fid p]S'pzh  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) }Y!V3s1bm  
        Close fid |GQq:MB;z  
    End If &cyB}Gv  
    Set oFSO = Nothing Pq+|*Y<|&  
    Return UBound( lineArray ) I(VqtC:K.  
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End Function *c4OhMU(  
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Sub GetFileList( ByVal in_dir As String, _ <$?#P#A  
                 ByRef in_flist() As String ) Cu%BU}(  
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    'Redimension the file list array I
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    Erase in_flist {91Y;p C  
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    'Tracks how many files are found PtuRXx  
    Dim fCount As Long A*0X~6W  
    fCount = 0 .a2R2~35  
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    'Recurse directory and search for text files 8t=H  
    Dim f As String Y{j~;G@Wl  
    f = Dir$(in_dir & "*.txt") +?6]Vu&|f  
    While f <> "" -ABj>y[  
        ReDim Preserve in_flist(fCount) ^3sv2wh^|8  
        in_flist(fCount) = f qdk!.A{  
        fCount += 1 2
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        f = Dir$() HHw&BNQG  
    Wend j^#\km B  
    ReDim Preserve in_flist(fCount-1) V$DB4YM1k  
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End Sub 9-j-nx @)