[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： (/2rj[F&  
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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。 Q7<Y5+  
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背景： ~n8UN<  
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。 'z^'+}iyv  
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。 w[F})u]E  
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步骤 <jh7G  
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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。 X&HYWH'@,  
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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） :1Nc6G  
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  Cu5_OJ  
例如下所示： @D=B5f@(o  
Sample name:  EDF-C1-56 w+"E{#N  
Merging data from file EDF-C1-56 0-0.txt q_6lD~~q^  
Finished merging RPC data for sample EDF-C1-56 { TI,|'>5[  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt *+zFsu4l  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 _YG@P1  
a. 创建一个新的散射库 XlD=<$Nk7  
b. 散射模型命名 gxmo 1  
c. 改变散射模型为“Tabulated BSDF”. unc6 V%  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） tvf5b8(Y-  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 w&f>VB~,1  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线，  ZB|s/  
g. 点击OK A9N8Hav  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 4i.&geXA.  
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脚本代码： M*bsA/Z  
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'#Language "WWB-COM" X31%T"  
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Option Explicit 5=8v\q?)c  
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Sub Main 5L<A7^j  
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    'Cleanup wh8;:<|  
    ClearOutputWindow() Y'jgp Vt  
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    Print "Merging RPC Photonics BSDF Data Files" x0>N{ADXQ  
    SetTextColor(255,0,0) -fV\JJ  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." % >a /m.$  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." k>Fw2!mA^  
    SetTextColor(0,0,0) pGD-K41O]  
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    'Current directory of this script (should be the same as the text files being merged) Xs|d#WbX  
    Dim cDir As String :R +BC2x  
    cDir = MacroDir$ & "\" j:uq85s  
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    'Array which will be populated with the list of files to be merged [kpQ:'P3
 
    Dim fList() As String, curFile As String *~4<CP+"0  
    GetFileList( cDir, fList ) c%O97J.5b  
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    Print "" KPDJ$,
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    Print "Files found for merging:" @aN~97 H\  
    For Each curFile In fList cAGM|%  
        Print Chr(9) & curFile S&-F(#CF^  
    Next #g@4c3um|  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. |A,.mOT  
    Dim nameArray() As String, sampName As String cUP1Uolvn  
    nameArray = Split(fList(0)," 0-0.txt") \!jz1`]&{  
    sampName  = nameArray(0) fj['M6+wd  
    Print "" g"Hl 30o  
    Print "Sample name: " & Chr(9) & sampName ?D7zty+}^  
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    'Open an output file and write the FRED header data 8%?MRRK  
    Dim outFile As String <&`Rf6  
    outFile = cDir & sampName & "_FRED.txt" 2Mq
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    Open outFile For Output As #1 k<j]b^jbz  
    Print #1, "type bsdf_data" 2"|7 YI  
    Print #1, "format angles=deg bsdf=value scale=1" }@jJv||  
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    'Loop the file list, skip the two header lines and write the remaining data to file
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    Dim lineArray() As String, curLine As Long O(-6Zqk8Q  
    For Each curFile In fList b@=H$"  
        Print "Merging data from file " & curFile z79oj\&[  
        ReadFile( cDir & curFile, lineArray ) tUZfQ  
        For curLine = 2 To UBound(lineArray) pO fw *lD  
            Print #1, lineArray(curLine) +:jv )4^O  
        Next +A1*e+/b\  
    Next K$GQc"  
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    'Close the output file [>
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    Close #1 _qk&W_u  
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    Print "Finished merging RPC data for sample " & sampName vg3iT}  
    Print "FRED formatted data file: " & Chr(9) & outFile ? p[Rv  
End Sub tI^[|@,  
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'Utility function to read the contents of a file into an array of strings. pZ[|Q2(  
Function ReadFile(ByVal fileName As String, _ N}[!QE  
                  ByRef lineArray() As String) As Long 3G 5xIr6   
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    ReadFile = -1 =d<~
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    Dim oFSO As Object Ktt(l-e+  
    Set oFSO = CreateObject("Scripting.FileSystemObject") =zrfh-lwH  
    Erase lineArray ;.xKVH/@  
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    Dim fid As Long vA ZkT"  
    If oFSO.fileexists( fileName ) Then 0*kS\R=P  
        fid = FreeFile()  !a\HdQ  
        Open fileName For Input As fid }X=c|]6i^  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) Voq/0,d  
        Close fid ZQir?1=  
    End If
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    Set oFSO = Nothing _ MB
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    Return UBound( lineArray ) LfU? 1:Du  
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End Function 'qde#[VB  
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Sub GetFileList( ByVal in_dir As String, _ FL^t}vA  
                 ByRef in_flist() As String ) kEAF1RP:  
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    'Redimension the file list array mea} 9]c  
    Erase in_flist Wlq3r#  
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    'Tracks how many files are found lfd-!(tXD  
    Dim fCount As Long c05-1  
    fCount = 0 i|,}y`C#  
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    'Recurse directory and search for text files P|lDW|}D@  
    Dim f As String /[/{m]  
    f = Dir$(in_dir & "*.txt") .!lLj1?p  
    While f <> "" XhWo~zh"  
        ReDim Preserve in_flist(fCount) 1=9GV+`n  
        in_flist(fCount) = f S1~K.<B  
        fCount += 1 3m-g-  
        f = Dir$() #)48dW!n  
    Wend O}2/w2n  
    ReDim Preserve in_flist(fCount-1) +R;LHRS%  
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End Sub v_v>gPl,