[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： 9g>]m6  
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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。 r$;DA<<|<c  
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背景： g6Qzkvw)  
Thorlabs和RPC Photonics联手共同推出的新型漫射体及光束整形技术，可以解决其他技术的不足，大大改善了诸如光刻系统、有效固态照明，显示，背光，显示亮度增强和投影屏等大多数应用的性能。这项我们称之为工程漫射体（Engineered DiffusersTM）的新概念，与其他技术有许多不同。与诸如磨砂玻璃、乳色玻璃和全息元件等随机漫射体截然不同，工程漫射体要求对于每个散射中心，通常为微透镜单元，都进行控制。例如全息漫射体可以视为一组随机排列的透镜，但是通过全息曝光形成的类透镜效果只能通过静态方式进行控制：而无法单独操控每个微透镜单元，这也帮助解释了全息漫射体无法控制光的分布和轮廓。另一方面，在工程漫射体中，每个微透镜单元形成漫射体，由其凹形纵断面和在阵列中的位置所确定。同时，为了确保漫射体不受输入光束变化的影响，并且不产生衍射效果，微透镜单元的分布是随机的，根据产生相应的光束形状函数所选取的概率分布函数来确定。因此，工程漫射体同时保留了随机与确定性漫射体的优点，从而实现高性能的光束整形功能。 wED~^[]f  
FRED是美国Photon Engineering 公司开发的光学工程仿真软件，其在杂散光分析中独特的算法、高效的准确性，使其与其它同类产品相比更具优势。本案例我们重点讲述如何由RPC Photonics的BSDF数据转为FRED可识别的散射数据。 Y%p"RB[  
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步骤 ?F*gFW_k  
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1、 在http://www.rpcphotonics.com/bsdf-data-optical-diffusers/下载并解压BSDF数据到某一文件夹下，选择“Raw data”文件。 NeCTEe|V  
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2、 将     http://fred-kb.photonengr.com/wp-content/uploads/sites/2/2015/06/constructRpcScatterFile.frs脚本文件放在步骤1中的文件下。（脚本代码放在了本文的最后） %,a.431gi  
3、 打开FRED并运行脚本文件，会输出如下“<SAMPLE>_FRED.txt”格式，<SAMPLE>即为RPC Photonics散射片数据集 !-x^b.${B  
例如下所示： \`{ YqOT  
Sample name:  EDF-C1-56 -{pcb7.xuv  
Merging data from file EDF-C1-56 0-0.txt '68{dyFZL  
Finished merging RPC data for sample EDF-C1-56 rv;w`f  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt 7\JRHw  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 >T.U\,om7  
a. 创建一个新的散射库 KLsTgo|J  
b. 散射模型命名 W=mh*G3y  
c. 改变散射模型为“Tabulated BSDF”. fcr\XCG7U  
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 ） SWO$#X /  
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。 M^mS#<!y  
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， R2x(8k"LPU  
g. 点击OK S`K8e^]
 
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 ~8`r.1aUO  
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脚本代码： & @^|=>L  
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'#Language "WWB-COM" %l,p />r  
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Option Explicit q3T'rw%Eh  
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Sub Main *<xEM-  
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    'Cleanup ,S:g5n>M  
    ClearOutputWindow() a5?Rj~h!<  
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    Print "Merging RPC Photonics BSDF Data Files" |6"zIHvtc  
    SetTextColor(255,0,0) 0#G&8*FMN  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." q,^^c
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    Print "Note: Do not run this script multiple times without deleting the output file between executions." ;,JCA# N  
    SetTextColor(0,0,0) 477jS6^e&  
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    'Current directory of this script (should be the same as the text files being merged) N02N w(pi  
    Dim cDir As String dW,$yH_  
    cDir = MacroDir$ & "\" t{Q9Kv  
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    'Array which will be populated with the list of files to be merged 6@ET3v  
    Dim fList() As String, curFile As String fE|([` !  
    GetFileList( cDir, fList ) G7M:LcX  
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    Print "" $a(wM1S4  
    Print "Files found for merging:" ^B1Q";# B^  
    For Each curFile In fList Q^DKKp  
        Print Chr(9) & curFile K {!eHTU  
    Next EbY%:jR  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. y2TJDb1  
    Dim nameArray() As String, sampName As String Pp@P]  
    nameArray = Split(fList(0)," 0-0.txt") +g/y)]AP  
    sampName  = nameArray(0) `Q,moz  
    Print "" g.s~Ph-G  
    Print "Sample name: " & Chr(9) & sampName 06]J]  
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    'Open an output file and write the FRED header data +K; X$kB  
    Dim outFile As String Z[FSy-;"  
    outFile = cDir & sampName & "_FRED.txt" mmu{K$9}I  
    Open outFile For Output As #1 [q?{
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    Print #1, "type bsdf_data" b9%hzD,MR  
    Print #1, "format angles=deg bsdf=value scale=1" 4@4$kro  
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    'Loop the file list, skip the two header lines and write the remaining data to file bEMD2ABm  
    Dim lineArray() As String, curLine As Long =Mc*~[D/  
    For Each curFile In fList egYJ.ZzF0  
        Print "Merging data from file " & curFile E/Q[J.$o  
        ReadFile( cDir & curFile, lineArray ) [_^K}\/+  
        For curLine = 2 To UBound(lineArray) TC<_I0jCh  
            Print #1, lineArray(curLine) MkRRBv
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        Next |/
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    Next D+9xI  
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    'Close the output file ';^VdR]fk  
    Close #1 Pn[-{nz  
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    Print "Finished merging RPC data for sample " & sampName ,*+F
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    Print "FRED formatted data file: " & Chr(9) & outFile {<v?Z_!68  
End Sub GASDkVoij  
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'Utility function to read the contents of a file into an array of strings. ^{DXin 1O`  
Function ReadFile(ByVal fileName As String, _ _<+!  
                  ByRef lineArray() As String) As Long N41)?-7F  
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    ReadFile = -1 jav7V"$  
    Dim oFSO As Object ==RYf*d  
    Set oFSO = CreateObject("Scripting.FileSystemObject") }:])1!a  
    Erase lineArray ~5N0=)  
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    Dim fid As Long 9f\Lon4lX  
    If oFSO.fileexists( fileName ) Then DJdW$S7  
        fid = FreeFile() hbl:~O&a/  
        Open fileName For Input As fid 
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        lineArray = Split(Input(LOF(fid), fid), vbCrLf) Q( U+o-  
        Close fid b(Zh$86  
    End If mXtsP1  
    Set oFSO = Nothing Cvry
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    Return UBound( lineArray ) -y|>#`T/  
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End Function s/"&k  
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Sub GetFileList( ByVal in_dir As String, _ n`8BE9h^  
                 ByRef in_flist() As String ) 6!sC  
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    'Redimension the file list array -GJ~xcf0  
    Erase in_flist K|%.mcs4  
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    'Tracks how many files are found  ?12[8  
    Dim fCount As Long (HbA?Aja  
    fCount = 0 : E[\1  
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    'Recurse directory and search for text files G8z.JX-7g  
    Dim f As String cc- liY"  
    f = Dir$(in_dir & "*.txt") |L[/]@|  
    While f <> "" O?L6Ues  
        ReDim Preserve in_flist(fCount) aO)Cq5  
        in_flist(fCount) = f (yA`h@@WS  
        fCount += 1 "A\h+q-  
        f = Dir$() GVR/p  
    Wend 6l]jmj)/  
    ReDim Preserve in_flist(fCount-1) OIJNOuI  
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End Sub 0Lb:N]5m8