[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： emN*l]N  
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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。 u4h4.NHX  
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背景： Y/zj[>  
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。 @J`"[%U  
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。 ,nDaqQ-C!!  
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步骤 AkQ~k0i}b  
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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。 V33T+P~j  
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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） f=K]XTw~  
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 5]Y?m'  
例如下所示： ^3L0w
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Sample name:  EDF-C1-56 v,>Dbxn  
Merging data from file EDF-C1-56 0-0.txt I4i>+:_J  
Finished merging RPC data for sample EDF-C1-56 j+ 0I-p  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt A{D];pE`  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 &FN.:_E  
a. 创建一个新的散射库
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b. 散射模型命名 P me^l%M  
c. 改变散射模型为“Tabulated BSDF”. rCdu0 gYT  
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 ） y/ef>ZZ  
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。 Qjv}$`M  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， 338k?nHxv  
g. 点击OK 7\Y0z  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 zue~ce73J  
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脚本代码： \n|EM@=eE  
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'#Language "WWB-COM" H]Z$OpI  
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Option Explicit l?n\i]
'  
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Sub Main ]K,Tnyp  
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    'Cleanup ?QdWrE_  
    ClearOutputWindow() _5Ct]vy  
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    Print "Merging RPC Photonics BSDF Data Files" a'yK~;+_9  
    SetTextColor(255,0,0) Wf>R&o6tr  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." 68C%B9.b'  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." Ig0VW)@  
    SetTextColor(0,0,0) w-L=LWL\  
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    'Current directory of this script (should be the same as the text files being merged) ra gXn  
    Dim cDir As String mLLDE;7|}  
    cDir = MacroDir$ & "\" j/c&xv7=  
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    'Array which will be populated with the list of files to be merged 9w"4K.  
    Dim fList() As String, curFile As String 
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    GetFileList( cDir, fList ) m'=Crei  
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    Print "" 6HWE~`ok6  
    Print "Files found for merging:" lE(HFal0-(  
    For Each curFile In fList wc^tgE  
        Print Chr(9) & curFile ShP^A"Do  
    Next ~H<6gN<j(.  
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. hT&Y#fh  
    Dim nameArray() As String, sampName As String =ToyZm\  
    nameArray = Split(fList(0)," 0-0.txt") 9ZsVy
 
    sampName  = nameArray(0) Q1I6$8:7  
    Print "" a:OQGhc=  
    Print "Sample name: " & Chr(9) & sampName :zke %Yx  
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    'Open an output file and write the FRED header data _FU_Ubkr  
    Dim outFile As String A>
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    outFile = cDir & sampName & "_FRED.txt" u$Jz~:=,  
    Open outFile For Output As #1 }I6veagK  
    Print #1, "type bsdf_data" ;)z:fToh  
    Print #1, "format angles=deg bsdf=value scale=1" ;rGwc$?|  
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    'Loop the file list, skip the two header lines and write the remaining data to file nuMD!qu!nZ  
    Dim lineArray() As String, curLine As Long Vl=l?A8  
    For Each curFile In fList vm7z,FfN  
        Print "Merging data from file " & curFile +RMSA^  
        ReadFile( cDir & curFile, lineArray ) SaAFz&WRl  
        For curLine = 2 To UBound(lineArray) .*S#aq4S  
            Print #1, lineArray(curLine) ^Hnb}L  
        Next P90yI  
    Next )|R)Q6UJ  
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    'Close the output file J~zUp(>K  
    Close #1 '/n1IM$7  

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    Print "Finished merging RPC data for sample " & sampName 8hz^%vm  
    Print "FRED formatted data file: " & Chr(9) & outFile :vqgGKml$  
End Sub Ls$D$/:q?  
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'Utility function to read the contents of a file into an array of strings. PI:4m%[  
Function ReadFile(ByVal fileName As String, _ O1U=X:Zl  
                  ByRef lineArray() As String) As Long  Rn(ec  
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    ReadFile = -1 Ml{Z  
    Dim oFSO As Object aFb==73aLw  
    Set oFSO = CreateObject("Scripting.FileSystemObject") ~"&|W'he[  
    Erase lineArray {JO  
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    Dim fid As Long L:pYn_  
    If oFSO.fileexists( fileName ) Then r?lf($D*  
        fid = FreeFile() ~hnQUS`A  
        Open fileName For Input As fid JPc+rfF  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) 0y" $MC v  
        Close fid FxtQXu-g  
    End If r6MMCJ|G  
    Set oFSO = Nothing G%AbC"  
    Return UBound( lineArray ) Yz/md1T$  
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End Function vMi;+6'n>  
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Sub GetFileList( ByVal in_dir As String, _ 5T_n %vz  
                 ByRef in_flist() As String ) Ic"ybj`  
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    'Redimension the file list array Yq0| J  
    Erase in_flist ['X]R:3h  
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    'Tracks how many files are found i&Tbz!  
    Dim fCount As Long (
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    fCount = 0 HZzDVCU  
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    'Recurse directory and search for text files zl>nSndRE  
    Dim f As String 
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    f = Dir$(in_dir & "*.txt") < Mn ;  
    While f <> "" w;[NH/A^a  
        ReDim Preserve in_flist(fCount) J{p1|+h%  
        in_flist(fCount) = f '8RsN-w  
        fCount += 1 L3u&/Tn2  
        f = Dir$() "/*\1v9  
    Wend UUYSFa%  
    ReDim Preserve in_flist(fCount-1) axv>6k  
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End Sub t9kzw*U9