[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： z^/GTY  
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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。 ]k:m2$le  
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背景： iW}l[g8sw!  
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。 8-"5|pNc  
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。 NN 6KLbC(  
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步骤 6lWFxbh  
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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。 lZM3Q58?\  
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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） 2]3HX3  
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 ,GJ>vT)  
例如下所示： _qeuVi=A  
Sample name:  EDF-C1-56 6eT'[Umx  
Merging data from file EDF-C1-56 0-0.txt 1 j12Qn@]  
Finished merging RPC data for sample EDF-C1-56 R2O.}!'  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt uT}TSwgp  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 T#n1@FgC  
a. 创建一个新的散射库 7vaN&%;E%  
b. 散射模型命名 &@HNz6KO  
c. 改变散射模型为“Tabulated BSDF”. B`B%:#  
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 ） F>
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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。 N+M&d3H`  
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， cN WcNMm  
g. 点击OK N4H+_g|  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 MpA;cw]cI/  
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脚本代码： J`q}Ry;  
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'#Language "WWB-COM" ,![Du::1  
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Option Explicit `cP'~OT  

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Sub Main nF<y7XkO  
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    'Cleanup M7DLs;sD  
    ClearOutputWindow() %A62xnX  
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    Print "Merging RPC Photonics BSDF Data Files" A6N~UV*_  
    SetTextColor(255,0,0) >HPvgR/#BY  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." Aw4?y[{H  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." ,
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    SetTextColor(0,0,0) n#>.\F  
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    'Current directory of this script (should be the same as the text files being merged) ojx'g8yO  
    Dim cDir As String 5e)6ua,  
    cDir = MacroDir$ & "\" ~`2&'8  
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    'Array which will be populated with the list of files to be merged ov`^o25f  
    Dim fList() As String, curFile As String Ug7`ez4vw  
    GetFileList( cDir, fList ) +_X,
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    Print "" z!s.9  
    Print "Files found for merging:" UZje>.~?  
    For Each curFile In fList 5wH54gj}  
        Print Chr(9) & curFile .Iwur;/\  
    Next :}@C9pqr2  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. mDQEXMD  
    Dim nameArray() As String, sampName As String QqiJun_m  
    nameArray = Split(fList(0)," 0-0.txt") _[OF"X2  
    sampName  = nameArray(0) U g}8y8  
    Print "" [DZqCo  
    Print "Sample name: " & Chr(9) & sampName Z5G]p4  
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    'Open an output file and write the FRED header data c62dorDqy  
    Dim outFile As String xF( bS+(o  
    outFile = cDir & sampName & "_FRED.txt" A*8m8Sh$  
    Open outFile For Output As #1 e1 x^PT  
    Print #1, "type bsdf_data" C8IkpAD  
    Print #1, "format angles=deg bsdf=value scale=1" M{?zvq?d  
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    'Loop the file list, skip the two header lines and write the remaining data to file J~Cc9"(  
    Dim lineArray() As String, curLine As Long rv9B}%e  
    For Each curFile In fList d/D,P=j"  
        Print "Merging data from file " & curFile  hv+|s(  
        ReadFile( cDir & curFile, lineArray ) k"xGA*B|  
        For curLine = 2 To UBound(lineArray) BBHK  
            Print #1, lineArray(curLine) Deg!<[Nw  
        Next #zON_[+s9  
    Next {=3J/)='  

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    'Close the output file i2){xg~c  
    Close #1 #`W=mN(+k  
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    Print "Finished merging RPC data for sample " & sampName e`i7ah;  
    Print "FRED formatted data file: " & Chr(9) & outFile %35L=d[  
End Sub =p<?Hu  
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'Utility function to read the contents of a file into an array of strings. 9-0<*)"b>  
Function ReadFile(ByVal fileName As String, _ pzp,t(%j  
                  ByRef lineArray() As String) As Long 1/B]TT  
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    ReadFile = -1 L}'Yd'  
    Dim oFSO As Object aaDP9FW9e  
    Set oFSO = CreateObject("Scripting.FileSystemObject") '|A|vCRCG  
    Erase lineArray Hd9XfU  
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    Dim fid As Long qnB<k,8T  
    If oFSO.fileexists( fileName ) Then 'Qa5n\HX$  
        fid = FreeFile() @q K]JK  
        Open fileName For Input As fid `@[l\.Vt:  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) 9lf*O0Z&n  
        Close fid |0`hE;Kt7  
    End If y$X(S\W
 
    Set oFSO = Nothing q\%cFB}  
    Return UBound( lineArray ) 
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End Function UtnZNdlv  
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Sub GetFileList( ByVal in_dir As String, _ qve ./  
                 ByRef in_flist() As String ) bu>qsU3  
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    'Redimension the file list array H~noJIw#
 
    Erase in_flist eG5Y+iL-V  
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    'Tracks how many files are found j[I`\"  
    Dim fCount As Long (hIF]>,kl  
    fCount = 0 `K*b?:0lp  
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    'Recurse directory and search for text files j9d!yW  
    Dim f As String xg<Hxn,<M  
    f = Dir$(in_dir & "*.txt") =-NiO@5o  
    While f <> "" sIy  
        ReDim Preserve in_flist(fCount) (a@?s$LG  
        in_flist(fCount) = f aTd D`h  
        fCount += 1 O}Hf62"  
        f = Dir$() {`(>O"_[Q  
    Wend t42ub  
    ReDim Preserve in_flist(fCount-1) -'`TL$  
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End Sub .f:n\eT):