[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： 
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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。 %[F;TZt  
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背景： #z5?Y2t7~^  
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。 Olrw>YbW  
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。 jtCob'n8  
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步骤 B ~bU7.Cd  
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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。 i; uM!d}  
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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） )u:8Pv  
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 m/c~2?-;  
例如下所示： _C\ d^a(  
Sample name:  EDF-C1-56 SQCuY<mD  
Merging data from file EDF-C1-56 0-0.txt Hd}t=6  
Finished merging RPC data for sample EDF-C1-56 g5]DA.&(  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt u9%:2$[  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 PltPIu)F  
a. 创建一个新的散射库 [_GR'x'0x  
b. 散射模型命名 6iS+3+  
c. 改变散射模型为“Tabulated BSDF”. x?$Y<=vT  
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 ） g4932_tC  
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。 rV{e[fGd  
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， ZACn_gd[5  
g. 点击OK z>q_]U0  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 Tdp$laPO'  
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脚本代码： F.w#AV  
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'#Language "WWB-COM" }6(:OB?  
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Option Explicit eS+LFS7*k  
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Sub Main l0,O4k2'  
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    'Cleanup jP]'gQ!-w  
    ClearOutputWindow() uSbg*OA  
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    Print "Merging RPC Photonics BSDF Data Files" B)iJH  
    SetTextColor(255,0,0) jV8><5C  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." kE|#mI[>  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." ^u<+tV   
    SetTextColor(0,0,0) O`| ri5d  
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    'Current directory of this script (should be the same as the text files being merged) "d\8OOU  
    Dim cDir As String IT"jtV  
    cDir = MacroDir$ & "\" [\p0eUog/  
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    'Array which will be populated with the list of files to be merged EORAx  
    Dim fList() As String, curFile As String y->iv%
 
    GetFileList( cDir, fList ) 7u(i4O& k  
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    Print "" zAIC5fvu  
    Print "Files found for merging:" G 0 yt%qHE  
    For Each curFile In fList sa?;D  
        Print Chr(9) & curFile djp(s$:{4  
    Next u?i1n=Ne  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. W_EN4p~J  
    Dim nameArray() As String, sampName As String XDQ1gg`  
    nameArray = Split(fList(0)," 0-0.txt") 2;tp>,
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    sampName  = nameArray(0) 2:yv:7t/  
    Print "" :'=C/AL  
    Print "Sample name: " & Chr(9) & sampName F'!}$oT"  
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    'Open an output file and write the FRED header data x(~
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    Dim outFile As String Ws@s(5r  
    outFile = cDir & sampName & "_FRED.txt" TjdYCk]'  
    Open outFile For Output As #1 Gz:a1-x  
    Print #1, "type bsdf_data" j|9 2 g  
    Print #1, "format angles=deg bsdf=value scale=1" $+j)  
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    'Loop the file list, skip the two header lines and write the remaining data to file vC1 `m  
    Dim lineArray() As String, curLine As Long <Th.}=  
    For Each curFile In fList j3U8@tuG  
        Print "Merging data from file " & curFile |V5H(2/nk  
        ReadFile( cDir & curFile, lineArray ) 4a~_hkY]  
        For curLine = 2 To UBound(lineArray) rjzRH  
            Print #1, lineArray(curLine) M9nYt~vHX  
        Next 'u~use"  
    Next }^t?v*kcA  
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    'Close the output file Wj0([n  
    Close #1 UWp(3FQ  
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    Print "Finished merging RPC data for sample " & sampName ~yV0SpL  
    Print "FRED formatted data file: " & Chr(9) & outFile j~0hAKHG  
End Sub (nm&\b~j  
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'Utility function to read the contents of a file into an array of strings. GzX@Av$  
Function ReadFile(ByVal fileName As String, _ ~?FKww|_*J  
                  ByRef lineArray() As String) As Long 4T"P#)z  
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    ReadFile = -1 $= g
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    Dim oFSO As Object {^F_b% a4z  
    Set oFSO = CreateObject("Scripting.FileSystemObject") uWSG+  
    Erase lineArray ,h"M{W$  
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    Dim fid As Long B(hNBq7  
    If oFSO.fileexists( fileName ) Then  *hba>LZ  
        fid = FreeFile() ygHNAQG~  
        Open fileName For Input As fid e5dwq  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) a"EXR-+8  
        Close fid }
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    End If n:{yri+  
    Set oFSO = Nothing xM(  
    Return UBound( lineArray ) wp$=lU{B  
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End Function y9 "!ys  
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Sub GetFileList( ByVal in_dir As String, _ };
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                 ByRef in_flist() As String ) sy~mcH:%+  
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    'Redimension the file list array <5 okwcJ^  
    Erase in_flist Mw<1  
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    'Tracks how many files are found -1[ri8t;nV  
    Dim fCount As Long .d;/6HD[y  
    fCount = 0 `eA0Z:`g!  
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    'Recurse directory and search for text files 3=z'Ih`  
    Dim f As String vg<_U&N=-r  
    f = Dir$(in_dir & "*.txt") <=p"ck@  
    While f <> "" y<Z8+/f`f  
        ReDim Preserve in_flist(fCount) ,ua]h8  
        in_flist(fCount) = f K-K+%U  
        fCount += 1 -k'=s{iy  
        f = Dir$() :E.mU{  
    Wend `*!.B  
    ReDim Preserve in_flist(fCount-1) e_Y>
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End Sub MYu-[Hg