[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： 1'Rmg\(  
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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。 0e16Ow6\!1  
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背景： aClA{  
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。 nxfoWy  
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。 Bd# TUy  
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步骤 +D`*\d1  
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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。 QIK 9  
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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） #K|9^4jt  
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 ! %Ny0JkO  
例如下所示： Ryv_1gR!  
Sample name:  EDF-C1-56 `5l01nOxJ  
Merging data from file EDF-C1-56 0-0.txt 9:8|)a(1  
Finished merging RPC data for sample EDF-C1-56 "r$/  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt q.W>4 k  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 y}"7e)|t%  
a. 创建一个新的散射库 FnE6?~xa  
b. 散射模型命名 -c+]Wm"\  
c. 改变散射模型为“Tabulated BSDF”. dYF=c  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） WD.U"YI8y  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 WU)Ss`s \  
f. 在底部的对话框中，选择透射散射、反射停并且你需要终止入射光线， ^B]@Lr E^  
g. 点击OK 6Hf,6>  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 r4Q|5kT*i  
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脚本代码： E!mmLVa9  
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'#Language "WWB-COM" <[i}n55  
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Option Explicit 7lA:)a_!]  
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Sub Main tC)6  
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    'Cleanup iqPBsIW  
    ClearOutputWindow() 2*1ft>Uty  
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    Print "Merging RPC Photonics BSDF Data Files" ^+/kr/  
    SetTextColor(255,0,0) +B"0{>n}F  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." J2M(1g)t9  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." T?wzwGp-[  
    SetTextColor(0,0,0) ar^i|`D  
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    'Current directory of this script (should be the same as the text files being merged) \#Up|u:  
    Dim cDir As String fZ{[]dn[  
    cDir = MacroDir$ & "\" )jDJMi_[  
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    'Array which will be populated with the list of files to be merged |yY`s6Uq  
    Dim fList() As String, curFile As String L%h/OD  
    GetFileList( cDir, fList ) VaLs`q&3>  
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    Print "" >)**khuP7  
    Print "Files found for merging:" o\=n4;S  
    For Each curFile In fList 5V5w:U>_z  
        Print Chr(9) & curFile E>uVofhml
 
    Next

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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. #&8rcu;/  
    Dim nameArray() As String, sampName As String {/8
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    nameArray = Split(fList(0)," 0-0.txt") QP(BZJC  
    sampName  = nameArray(0) 9A$m$  
    Print "" k%81f'H  
    Print "Sample name: " & Chr(9) & sampName QlZ@ To  
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    'Open an output file and write the FRED header data /X*oS&-M  
    Dim outFile As String G| m4m.  
    outFile = cDir & sampName & "_FRED.txt" UKBJ_r  
    Open outFile For Output As #1 q3w1GD  
    Print #1, "type bsdf_data" ULqoCd%bK  
    Print #1, "format angles=deg bsdf=value scale=1" K[?Xm"4  
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    'Loop the file list, skip the two header lines and write the remaining data to file zGlZ!t:  
    Dim lineArray() As String, curLine As Long nE W31 8  
    For Each curFile In fList }}{Yw  
        Print "Merging data from file " & curFile 3Ofc\  
        ReadFile( cDir & curFile, lineArray ) rofNZ;nu  
        For curLine = 2 To UBound(lineArray) 
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            Print #1, lineArray(curLine) Y]g?2N=E  
        Next 5Fw
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    Next NL"G2[e  
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    'Close the output file _}6q{}jn:c  
    Close #1 dp5cDF}l  
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    Print "Finished merging RPC data for sample " & sampName S?0$?w?  
    Print "FRED formatted data file: " & Chr(9) & outFile zGo|JF  
End Sub ^+|De}`u  
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'Utility function to read the contents of a file into an array of strings. uE
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Function ReadFile(ByVal fileName As String, _ +cu^%CXT  
                  ByRef lineArray() As String) As Long |NFZ(6vNh  
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    ReadFile = -1
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    Dim oFSO As Object 0y#Ih {L  
    Set oFSO = CreateObject("Scripting.FileSystemObject") @'2m$a  
    Erase lineArray :!TIK1  
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    Dim fid As Long ^s:y/Kd  
    If oFSO.fileexists( fileName ) Then  #1nJ(-D+  
        fid = FreeFile() KLWDo%%u  
        Open fileName For Input As fid $.E6S<(h  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) t#E}NR  
        Close fid fxQN+6;  
    End If # TkR  
    Set oFSO = Nothing A<MtKb  
    Return UBound( lineArray ) H*I4xT@  
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End Function X@A1#z+s0]  
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Sub GetFileList( ByVal in_dir As String, _ L@Nu/(pB=  
                 ByRef in_flist() As String ) qt e>r  
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    'Redimension the file list array F\JUx L@8  
    Erase in_flist a:STQk V  
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    'Tracks how many files are found j Ch=@<9  
    Dim fCount As Long .p` pG3  
    fCount = 0 ,El!fgL  
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    'Recurse directory and search for text files ?uLeFD  
    Dim f As String ~+F;q vq  
    f = Dir$(in_dir & "*.txt") [#^#+ |{\  
    While f <> "" G@ \Pi#1  
        ReDim Preserve in_flist(fCount) je,}_:7  
        in_flist(fCount) = f %q3$|>  
        fCount += 1 p*QKK@C  
        f = Dir$() dI'SwnR  
    Wend CB\{!  
    ReDim Preserve in_flist(fCount-1) 3INI?y}t  
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End Sub iPG0o %