[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： ~A,(D-  
YAYwrKt  
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。 gCv[AIE_m  
osI0m7ws:  
背景： X oh@(%  
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。 z9ZS&=>  
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。 TZw['o  
#
#/ l  
n[  
lcuqzX{7  
步骤 dW#?{n-H<  
6yhRcvJ}  
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。 LqoH]AcN  
]h}O&K/  
aIklAj)=  
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）
xZ>@wBQ  
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 e)A{ {wD/  
例如下所示： t[X,m]SX  
Sample name:  EDF-C1-56 P B"nf|pm  
Merging data from file EDF-C1-56 0-0.txt :0(:}V3z\  
Finished merging RPC data for sample EDF-C1-56 2GJp`2(%dA  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt dyuT-.2  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 tq2TiXo%  
a. 创建一个新的散射库 2>Sr04Pt  
b. 散射模型命名 >3)AO04
=;  
c. 改变散射模型为“Tabulated BSDF”. l8RKwECdPn  
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 ） qaEWK0  
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。 e4Xo(EY &  
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， Cp^%;(@  
g. 点击OK ./Wi(p{F  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 T#D*B]oZ}  
Z~HLa  
T*zy^we  
脚本代码： J
|N>}di  
-|`
E'b81  
'#Language "WWB-COM" *sq+ Vc(  
5g4xhYl70n  
Option Explicit +3k#M[Bn}  
KAm$^N5  
Sub Main H263<^   
<77v8=as5  
    'Cleanup lv\^@9r  
    ClearOutputWindow() 9Q:}VpT~nG  
6x"|,,&MD0  
    Print "Merging RPC Photonics BSDF Data Files" }d16xp  
    SetTextColor(255,0,0) 7.7Z|lJ  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." lZ5TDS  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." _`q ei0  
    SetTextColor(0,0,0) 3R ZD=`  
gclw>((5  
    'Current directory of this script (should be the same as the text files being merged) =\)qUs\z  
    Dim cDir As String WkK.ON^  
    cDir = MacroDir$ & "\" e%.|PZ)  
A.(xa+z?  
    'Array which will be populated with the list of files to be merged 'tun;Y  
    Dim fList() As String, curFile As String d> L*2 g  
    GetFileList( cDir, fList ) 2[yfo8H  
`&qeSEs\  
    Print "" h}<Ie <  
    Print "Files found for merging:" 5=9gH  
    For Each curFile In fList 7wwlZ;w  
        Print Chr(9) & curFile 0} Lx}2  
    Next k{B;J\`E;  
4@*`V  
    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. XyytO;XM-  
    Dim nameArray() As String, sampName As String L*Q#!_K0P  
    nameArray = Split(fList(0)," 0-0.txt") e*jfxQ=qG  
    sampName  = nameArray(0) n%}Vd `c  
    Print "" qjVhBu7A  
    Print "Sample name: " & Chr(9) & sampName Q^\f,E\S  
S`Wau/7t  
    'Open an output file and write the FRED header data DF~{i{  
    Dim outFile As String J-+p]xG  
    outFile = cDir & sampName & "_FRED.txt" 3M<T}>  
    Open outFile For Output As #1 rdQ'#}Ix  
    Print #1, "type bsdf_data" %2`geN<  
    Print #1, "format angles=deg bsdf=value scale=1" ,?Nc\Q<:  
y|[YEY U)  
    'Loop the file list, skip the two header lines and write the remaining data to file #J)83  
    Dim lineArray() As String, curLine As Long 0FEn&\2<  
    For Each curFile In fList </7_T<He.  
        Print "Merging data from file " & curFile :h6
0  
        ReadFile( cDir & curFile, lineArray ) `]\:%+-  
        For curLine = 2 To UBound(lineArray) 8nOent0a  
            Print #1, lineArray(curLine) ctWH?b/ua  
        Next 5W~-|8m  
    Next coFQu ;i  
=}Xw}X+[WY  
    'Close the output file FV W&)-I  
    Close #1 8lcB.M  
H`X>  
    Print "Finished merging RPC data for sample " & sampName u&s>UkR  
    Print "FRED formatted data file: " & Chr(9) & outFile 
`#w`-  
End Sub ]0&ExD\4  
b~<Tgo_/jf  
'Utility function to read the contents of a file into an array of strings. @I,:(<6  
Function ReadFile(ByVal fileName As String, _ X6lUFko  
                  ByRef lineArray() As String) As Long Af{K#R8!  
d ,!sZ&v  
    ReadFile = -1 gg%9EJpP  
    Dim oFSO As Object r>gU*bs(  
    Set oFSO = CreateObject("Scripting.FileSystemObject") RFq&#3f$  
    Erase lineArray tOf18V{a  
}iCcXZ&5^  
    Dim fid As Long 0-a[[hL?  
    If oFSO.fileexists( fileName ) Then Y<oDv`aZ0  
        fid = FreeFile() &fuJ%  
        Open fileName For Input As fid 3 h~U)mg  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) Oe:_B/l  
        Close fid [j^c&}0  
    End If #_}r)q  
    Set oFSO = Nothing U>jLh57  
    Return UBound( lineArray ) 2or!v^^u  
8mpoY.E4!  
End Function skRI\  
*dE5yS`H  
Sub GetFileList( ByVal in_dir As String, _ G'qGsKf\  
                 ByRef in_flist() As String ) 6}9`z8  
tfb_K4h6,  
    'Redimension the file list array o(_~ st<  
    Erase in_flist #>/stU-  
4|[)D/N  
    'Tracks how many files are found FY6!)/P0I7  
    Dim fCount As Long mfpL?N  
    fCount = 0 (fJ.o-LQ  
F;@A2WD  
    'Recurse directory and search for text files cw)'vAE  
    Dim f As String 4RYvI!
 
    f = Dir$(in_dir & "*.txt") eED@Z/~
6  
    While f <> "" 'E#;`}&Ah  
        ReDim Preserve in_flist(fCount) r=o\!sh[  
        in_flist(fCount) = f P:8P>#L  
        fCount += 1 ehCZhi~  
        f = Dir$() 6*92I  
    Wend +GqV9x 8  
    ReDim Preserve in_flist(fCount-1) 7,![oY[  
(#"iZv,  
End Sub jJfV_#'N'