[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： @Feusprs  
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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。 \+?>KpE,b  
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背景： Vxr_2Kra  
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。 o{W4@:Ib  
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。 2 }9of[  
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步骤 xJ-(]cO'  
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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。 ZWtlOP#]  
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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） O#}d!}SIp  
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 "7> o"FQ  
例如下所示： A
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Sample name:  EDF-C1-56 AQUl:0!  
Merging data from file EDF-C1-56 0-0.txt D.!ay>o0#  
Finished merging RPC data for sample EDF-C1-56 g':/hlQ  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt aEO``W  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 +t9$*i9`L  
a. 创建一个新的散射库 34D7qR  
b. 散射模型命名 FnZMW, P  
c. 改变散射模型为“Tabulated BSDF”. Mu1H*;_8  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） ~PTqR2x  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 @]{+9m8G@  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， sI/]pgt2  
g. 点击OK ]j4Nl?5*x  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 Kyr3)1#J  
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脚本代码： =DL |Q  
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'#Language "WWB-COM" I[x+7Y0k9  
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Option Explicit p aQ"[w  
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Sub Main
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    'Cleanup eU*0;#  
    ClearOutputWindow() x)]_]_vX  
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    Print "Merging RPC Photonics BSDF Data Files" ?Z1&ju,Hd-  
    SetTextColor(255,0,0) KTmduf7DL  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." x5X;^.1Fr  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." 3PBGIo  
    SetTextColor(0,0,0) sy\w ^]  
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    'Current directory of this script (should be the same as the text files being merged) 'j#J1xwJ  
    Dim cDir As String 8et*q3D7`  
    cDir = MacroDir$ & "\" ,/bSa/x`  
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    'Array which will be populated with the list of files to be merged ( !THd  
    Dim fList() As String, curFile As String WGK:Xf
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    GetFileList( cDir, fList ) .`ND  
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    Print "" G1!yPQa7d  
    Print "Files found for merging:" #A:+|{H"  
    For Each curFile In fList !5wuBJ0  
        Print Chr(9) & curFile |riP*b
 
    Next cn3F3@_"\  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. @)IHd6 R  
    Dim nameArray() As String, sampName As String q!qOy/}D  
    nameArray = Split(fList(0)," 0-0.txt") 2#XYR>[  
    sampName  = nameArray(0) _MI8P/  
    Print "" i3SrsVSG  
    Print "Sample name: " & Chr(9) & sampName 2_i9 q>I  
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    'Open an output file and write the FRED header data gZg5On  
    Dim outFile As String /uNgftj  
    outFile = cDir & sampName & "_FRED.txt" #+Pk_
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    Open outFile For Output As #1 (v@)nv]U  
    Print #1, "type bsdf_data" .boBo$f  
    Print #1, "format angles=deg bsdf=value scale=1" 'G#T 6B!  
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    'Loop the file list, skip the two header lines and write the remaining data to file C&1()U  
    Dim lineArray() As String, curLine As Long [bK5q;#U4  
    For Each curFile In fList VJf|r#2  
        Print "Merging data from file " & curFile &yabxl_  
        ReadFile( cDir & curFile, lineArray ) %77X/%.Y  
        For curLine = 2 To UBound(lineArray) ?RMOy$L  
            Print #1, lineArray(curLine) '=V!Y$tn  
        Next Pw:{  
    Next T`7HQf ;  
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    'Close the output file X9S`#N  
    Close #1 ~CRd0T[^  
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    Print "Finished merging RPC data for sample " & sampName *URBx"5XZ  
    Print "FRED formatted data file: " & Chr(9) & outFile #J):N  
End Sub gR]NH  
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'Utility function to read the contents of a file into an array of strings. ' ~F  
Function ReadFile(ByVal fileName As String, _ h8)m2KrZ!.  
                  ByRef lineArray() As String) As Long _[:>!ekx  
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    ReadFile = -1 iL6Yk @  
    Dim oFSO As Object ~ZuFMVR  
    Set oFSO = CreateObject("Scripting.FileSystemObject") 2x<A7l)6  
    Erase lineArray 6`JY:~V"  
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    Dim fid As Long F3Y/Miw  
    If oFSO.fileexists( fileName ) Then dU"ca|u  
        fid = FreeFile() <8,,pOb  
        Open fileName For Input As fid p7{%0
  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) .m^L,;+2  
        Close fid "rJJ~[Y  
    End If c*~/`lG  
    Set oFSO = Nothing pFW^  
    Return UBound( lineArray ) (]}52%~  
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End Function tF&g3)D:NV  
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Sub GetFileList( ByVal in_dir As String, _ 6oA2"!u^w  
                 ByRef in_flist() As String ) ,'%w
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    'Redimension the file list array QO;OeMQv%  
    Erase in_flist 4Y/kf%]]A  
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    'Tracks how many files are found Gkr?M^@K  
    Dim fCount As Long 5IJm_oy  
    fCount = 0 +~{Honj[  
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    'Recurse directory and search for text files d&x #9ka  
    Dim f As String =K:)%
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    f = Dir$(in_dir & "*.txt") ,g~Iup  
    While f <> "" 4F=cER6l  
        ReDim Preserve in_flist(fCount) .VG5 / 6zp  
        in_flist(fCount) = f IJQ" *;  
        fCount += 1 OciPd/6  
        f = Dir$() K4w#}gzok  
    Wend n8RE  
    ReDim Preserve in_flist(fCount-1) j-%@A`j;  
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End Sub V\
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