[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： IRg2\Hq  
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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。 Lc~m`=B  
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背景： N[ =I  
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。 \hX,z =  
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。 !sX$?P%U  
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步骤 zh) &6'S\  
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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。 eP~
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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） 21OfTV-+3  
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 =\]gL%N-|  
例如下所示： #)S}z+I  
Sample name:  EDF-C1-56 #<Y.+:  
Merging data from file EDF-C1-56 0-0.txt TzC(YWt  
Finished merging RPC data for sample EDF-C1-56 .45wwouZkc  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt p>)1Z<D"a  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 -}m  
a. 创建一个新的散射库 ai;!Q%B#Q  
b. 散射模型命名 @ fMlbJq  
c. 改变散射模型为“Tabulated BSDF”. 0c>>:w20D  
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 ） Lx-%y
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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。 6Y[&1c8  
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， k?h{6Qd  
g. 点击OK VQ!4( <XD  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 )[hs#nKTh  
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脚本代码： )%jS9e{d  
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'#Language "WWB-COM" u0R[TA3  
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Option Explicit ybJa:  
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Sub Main R{}_Qb  
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    'Cleanup x/1FQ>n:9  
    ClearOutputWindow() +]t9kr  
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    Print "Merging RPC Photonics BSDF Data Files" ?bd!JW bg`  
    SetTextColor(255,0,0) QqL?? p-S>  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." "Io-%Su+  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." NZ`6iK-V_  
    SetTextColor(0,0,0) \nOV2(FAT  
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    'Current directory of this script (should be the same as the text files being merged) ~b8.]Z^  
    Dim cDir As String G%gdI3h1Z  
    cDir = MacroDir$ & "\" H?opG<R=ek  
' Sd&I:
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    'Array which will be populated with the list of files to be merged RGV{KL  
    Dim fList() As String, curFile As String gu3)HCZ  
    GetFileList( cDir, fList ) .aZB?MW  
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    Print "" R7Tl1!,h  
    Print "Files found for merging:" xG~-.  
    For Each curFile In fList 7TAoWD3  
        Print Chr(9) & curFile ed,+Slg  
    Next q&ed4{
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    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. "~C\Z} ;  
    Dim nameArray() As String, sampName As String a
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    nameArray = Split(fList(0)," 0-0.txt") >y+j!)\  
    sampName  = nameArray(0) M]\"]H?  
    Print "" &m(eMX0lU  
    Print "Sample name: " & Chr(9) & sampName @TKQ_7BcB  
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    'Open an output file and write the FRED header data EI9Yv>7d{  
    Dim outFile As String y^p%/p%  
    outFile = cDir & sampName & "_FRED.txt" [u3^R]  
    Open outFile For Output As #1 (I`<;  
    Print #1, "type bsdf_data" suj}A  
    Print #1, "format angles=deg bsdf=value scale=1" }xrrHp  
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    'Loop the file list, skip the two header lines and write the remaining data to file /7*qaG  
    Dim lineArray() As String, curLine As Long 1?+)T%"  
    For Each curFile In fList AMgvk`<f  
        Print "Merging data from file " & curFile nDC5/xB  
        ReadFile( cDir & curFile, lineArray ) hYCyc-W  
        For curLine = 2 To UBound(lineArray) G`!;RX  
            Print #1, lineArray(curLine) /|e"0
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        Next Qzk/oHs  
    Next J! eVw\6  
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    'Close the output file 6a`_i  
    Close #1 a-TsD}'X  
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    Print "Finished merging RPC data for sample " & sampName sEfGf.  
    Print "FRED formatted data file: " & Chr(9) & outFile ^_ZQf  
End Sub Vo2fr
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'Utility function to read the contents of a file into an array of strings. **YNR:#Y  
Function ReadFile(ByVal fileName As String, _ w
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                  ByRef lineArray() As String) As Long  K[TMTn  
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    ReadFile = -1 s?K4::@Fv  
    Dim oFSO As Object El&pux2  
    Set oFSO = CreateObject("Scripting.FileSystemObject") '*p-`  
    Erase lineArray $t</{]iX  
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    Dim fid As Long TAJ9Y<  
    If oFSO.fileexists( fileName ) Then 7!N5uR  
        fid = FreeFile() VF==F_l  
        Open fileName For Input As fid M!6bf  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) tT#Q`c
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        Close fid 8UL:C?eY  
    End If GrQAho  
    Set oFSO = Nothing ?y45#Tk]  
    Return UBound( lineArray ) qaGIU`}:$A  
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End Function |QgXSe7  
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Sub GetFileList( ByVal in_dir As String, _ izWl5}+'B  
                 ByRef in_flist() As String ) 'Jl.fN  
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    'Redimension the file list array /~tfP  
    Erase in_flist }>XSp)"{l  
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    'Tracks how many files are found x?<5=,  
    Dim fCount As Long `y6l^
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    fCount = 0 gS|xicq!  
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    'Recurse directory and search for text files =
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    Dim f As String >`\*
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    f = Dir$(in_dir & "*.txt") FfgJ 2y  
    While f <> "" {4m"S7O  
        ReDim Preserve in_flist(fCount) 1W!n"3#  
        in_flist(fCount) = f ]D-4
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        fCount += 1 O}D
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        f = Dir$() 9FLn7Y  
    Wend ?Ru`ma\;  
    ReDim Preserve in_flist(fCount-1) i:8^:(i  
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End Sub ry]7$MQyV