[分享]RPC Photonics扩散片BSDF [复制链接]

摘要：  qg+bh  
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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。 S
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背景： voHFU#Z$  
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。 ny]R,D0  
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。 cj!Ew}o40D  
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步骤 TEK]$%2  
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1、 在http://www.rpcphotonics.com/bsdf-data-optical-diffusers/下载并解压BSDF数据到某一文件夹下，选择“Raw data”文件。 :sY pZX1  
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2、 将     http://fred-kb.photonengr.com/wp-content/uploads/sites/2/2015/06/constructRpcScatterFile.frs脚本文件放在步骤1中的文件下。（脚本代码放在了本文的最后） 5k^UZw  
3、 打开FRED并运行脚本文件，会输出如下“<SAMPLE>_FRED.txt”格式，<SAMPLE>即为RPC Photonics散射片数据集 L/VlmN_v>s  
例如下所示： o=1M<dL  
Sample name:  EDF-C1-56 0;kp`hB  
Merging data from file EDF-C1-56 0-0.txt }smPP*  
Finished merging RPC data for sample EDF-C1-56 1%nE  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt 4{s3S2f=  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 Yc,qXK-  
a. 创建一个新的散射库 |aT&rpt  
b. 散射模型命名 .cV<(J 5o  
c. 改变散射模型为“Tabulated BSDF”. ,/=Fm  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） d,_Ky#K5b  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。
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f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， (0=e ,1 n  
g. 点击OK ;ss,x  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 :|\{mo1NB  
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脚本代码： 
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'#Language "WWB-COM" mP@<UjxI  
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Option Explicit cF[L6{Oe  
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Sub Main DaV:Slp9  
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    'Cleanup <Oi65O_X  
    ClearOutputWindow() 8+>r!)Q+  
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    Print "Merging RPC Photonics BSDF Data Files" fr\"MP  
    SetTextColor(255,0,0) LovVJ^TD0i  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." TJHab;7F  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." DcO$&)Eb  
    SetTextColor(0,0,0) {
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    'Current directory of this script (should be the same as the text files being merged) T=EHue$  
    Dim cDir As String %[<@$qP  
    cDir = MacroDir$ & "\" yBJf'-K  
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    'Array which will be populated with the list of files to be merged -A?6)ggf.  
    Dim fList() As String, curFile As String 4@b~)av)  
    GetFileList( cDir, fList ) J
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    Print "" =i4%KF9x  
    Print "Files found for merging:" ,eI2#6w|C  
    For Each curFile In fList cN#c25S>  
        Print Chr(9) & curFile 3tO=   
    Next >9Yo:b:f  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. [9wuaw"~[Z  
    Dim nameArray() As String, sampName As String $ ]ew<j  
    nameArray = Split(fList(0)," 0-0.txt")
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    sampName  = nameArray(0) <sALA~p|0  
    Print "" \iBEyr]  
    Print "Sample name: " & Chr(9) & sampName I`$"6 Xy  
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    'Open an output file and write the FRED header data ~o_zV'^f@o  
    Dim outFile As String X]Aobtz  
    outFile = cDir & sampName & "_FRED.txt" =bx;TV  
    Open outFile For Output As #1 #-]!;sY>  
    Print #1, "type bsdf_data" 3 #8bG(  
    Print #1, "format angles=deg bsdf=value scale=1" `b11,lg  
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    'Loop the file list, skip the two header lines and write the remaining data to file SBf8Ipe  
    Dim lineArray() As String, curLine As Long 9+"R}Nxv^  
    For Each curFile In fList 9J*M~gKbz  
        Print "Merging data from file " & curFile }f l4^F  
        ReadFile( cDir & curFile, lineArray ) cYC@@?  
        For curLine = 2 To UBound(lineArray) m-<"`:+  
            Print #1, lineArray(curLine) ;?{N=x8  
        Next oMb&a0-7u  
    Next ]4uY<9VL  
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    'Close the output file g< F7UA  
    Close #1 \>DMN #  
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    Print "Finished merging RPC data for sample " & sampName ajy+%sXf=  
    Print "FRED formatted data file: " & Chr(9) & outFile 4x2 ;@Pd  
End Sub /8Sr(  
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'Utility function to read the contents of a file into an array of strings. )YtdU(^J$  
Function ReadFile(ByVal fileName As String, _ ^$!H|  
                  ByRef lineArray() As String) As Long ?2q;`Nb  
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    ReadFile = -1 {:63% j  
    Dim oFSO As Object tL#]G?0d  
    Set oFSO = CreateObject("Scripting.FileSystemObject") Izapx\GK9  
    Erase lineArray g'%^-S ]  
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    Dim fid As Long ;VS\'#{e  
    If oFSO.fileexists( fileName ) Then Wx`|u  
        fid = FreeFile() Ft[)m#Dj`  
        Open fileName For Input As fid \#hp,XV>  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) yP
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        Close fid b9%G"?~Zz  
    End If %>mB"Y,  
    Set oFSO = Nothing M[= #%U3*N  
    Return UBound( lineArray ) ?BEO(;'  
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End Function <hv {,1p-r  
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Sub GetFileList( ByVal in_dir As String, _ < %t$0'  
                 ByRef in_flist() As String ) NbyXi3@v  
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    'Redimension the file list array s?,\aSsU@  
    Erase in_flist x\R%hGt  
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    'Tracks how many files are found |EjMpRNE  
    Dim fCount As Long sT<XZLu  
    fCount = 0 skeXsls  
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    'Recurse directory and search for text files %n!7'XF'[  
    Dim f As String EQvZ(-_;4  
    f = Dir$(in_dir & "*.txt") t*Xo@KA  
    While f <> "" m35$4  
        ReDim Preserve in_flist(fCount) s6YnNJ,SK  
        in_flist(fCount) = f )/Mk\``j  
        fCount += 1 'Cp]Q@]\  
        f = Dir$() +FGw)>g8'm  
    Wend s~)I1G  
    ReDim Preserve in_flist(fCount-1) V-N`R-FSr  
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End Sub 3yXSv1  
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