[技术]RPC Photonics扩散片BSDF [复制链接]

摘要： 7# !RX3  
dC,a~`%O  
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。 %)o'9  
yzI`&? P2  
背景： ^qR2!fwm<  
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。 -/)>DOgUq  
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。 SHcFnxEAIH  
STln_'DF'  
OS- Xh-:z  
[T}Lq~  
步骤 Hs6?4cgj  
c2E*A+V#u  
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。 &AUtUp kOo  
'DeI]IeP  
3aX/)v.:4  
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） Z.QgL=  
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 2oBT _o%/J  
例如下所示： Z(h.)$yH*=  
Sample name:  EDF-C1-56 G>@KX  
Merging data from file EDF-C1-56 0-0.txt azBYh*s=5{  
Finished merging RPC data for sample EDF-C1-56 $:l>g)c  
FRED formatted data file:  D:\FRED\散射片数据\EDF-C1-56_FRED.txt NP#6'eH\  
4、 生成了FRED可识别的文件后，将散射模型导入到FRED里面 ?:woUTyCv  
a. 创建一个新的散射库 @yImR+^.7  
b. 散射模型命名 I,8f{T!O@"  
c. 改变散射模型为“Tabulated BSDF”. n5qg6(Tl]  
d. 在File框出右键选择“Replace With Data From a File”, 选择步骤三生成的数据文件（如EDF-C1-56_FRED.txt ） y]U]b G{  
e. 切换为“Varies w/angle” 选项（假定所有的RPC Photonics datasets 数据有多个测试角度。 %$Smei
 
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， =Ts5\1sc>  
g. 点击OK 3u,CI!  
5、 数据输入后，可点击“Plot”按钮验证BSDF模型及总的散射值 ; <NK  
|^09ny|  
-xVp}RLT  
脚本代码： KHO@"+  
C0`Bi:Ze  
'#Language "WWB-COM" :HiAjaA1pg  
QKB*N)%6  
Option Explicit Q\moR
^>  
T9'd?nw9  
Sub Main 93[&'  
F$6JzF$|F  
    'Cleanup ~NV 8avZ  
    ClearOutputWindow() :w,#RcW  
!'qY  
    Print "Merging RPC Photonics BSDF Data Files" h<0&|s*a)  
    SetTextColor(255,0,0) , RKl  
    Print "Note: Script should be located in the same folder as the BSDF TXT files." a #`Y(R'  
    Print "Note: Do not run this script multiple times without deleting the output file between executions." "h`oT4j5q  
    SetTextColor(0,0,0) 6"djX47j  
V<A$eb>6  
    'Current directory of this script (should be the same as the text files being merged) @,^c?v  
    Dim cDir As String 1Qk]?R/DN  
    cDir = MacroDir$ & "\" '>:c:Tewy  
b2r]>*Vc  
    'Array which will be populated with the list of files to be merged UTS.o#d  
    Dim fList() As String, curFile As String wl.a|~-  
    GetFileList( cDir, fList ) x@LNjlP  
2{}8_G   
    Print "" q]2t3aY%  
    Print "Files found for merging:" GoUsB|-\  
    For Each curFile In fList {9Ug9e{ ~  
        Print Chr(9) & curFile @>Bgld&vl  
    Next <p5?yF  
P _x(`H  
    'Split the first text file name found to get the sample name.  First file should be 0-0 measurement. =THRyZCH  
    Dim nameArray() As String, sampName As String )R^&u`k  
    nameArray = Split(fList(0)," 0-0.txt") dMw}4c3E  
    sampName  = nameArray(0) I83 _x|$FZ  
    Print "" uc>]-4  
    Print "Sample name: " & Chr(9) & sampName kxH` c  
`8lS)R!  
    'Open an output file and write the FRED header data p#aB0H3  
    Dim outFile As String 90Bn}@t=Q  
    outFile = cDir & sampName & "_FRED.txt" `e[>S  
    Open outFile For Output As #1 ;k:17&:8ue  
    Print #1, "type bsdf_data" #V$h?`qhwr  
    Print #1, "format angles=deg bsdf=value scale=1" q@&6&cd  
Dq[Z0"8  
    'Loop the file list, skip the two header lines and write the remaining data to file 1smKU9B2)  
    Dim lineArray() As String, curLine As Long .LI(2lP  
    For Each curFile In fList Wl0p-h  
        Print "Merging data from file " & curFile jB"IJ$cD  
        ReadFile( cDir & curFile, lineArray ) hX)PdRk#  
        For curLine = 2 To UBound(lineArray) b*)F7{/Z  
            Print #1, lineArray(curLine) t2LX@Q"  
        Next -P:o ^_)g  
    Next XGb*LY+Db6  
4DgH/Yo  
    'Close the output file {\vcwMUzZ  
    Close #1 D k<NlH zp  
eq(1'?7]`G  
    Print "Finished merging RPC data for sample " & sampName e'|IRhr  
    Print "FRED formatted data file: " & Chr(9) & outFile 1c|{<dFm  
End Sub }eAV8LU  
$d*PY_  
'Utility function to read the contents of a file into an array of strings. *X /i<  
Function ReadFile(ByVal fileName As String, _ <nU8.?\?~  
                  ByRef lineArray() As String) As Long ?0tm{qP  
:MihVLF  
    ReadFile = -1 RxE.t[  
    Dim oFSO As Object ?*^HZ~O1  
    Set oFSO = CreateObject("Scripting.FileSystemObject") t{-*@8Ke  
    Erase lineArray |OiM(E(  
x~QZVL=:  
    Dim fid As Long jG`,k*eUrJ  
    If oFSO.fileexists( fileName ) Then a0&L,7mu<'  
        fid = FreeFile() $ftxid8  
        Open fileName For Input As fid _BoYyJQH  
        lineArray = Split(Input(LOF(fid), fid), vbCrLf) i
?%_Pu  
        Close fid qVssw* GDB  
    End If 0TaN#  
    Set oFSO = Nothing 3b?8<*  
    Return UBound( lineArray ) ?vP6~$*B  
JAX`iQd  
End Function Dkg^B@5Xr  
lhX4MB"  
Sub GetFileList( ByVal in_dir As String, _ E[Q2ZqhgbP  
                 ByRef in_flist() As String ) u7SC_3R  
eD|"?@cE  
    'Redimension the file list array M5:j)oW  
    Erase in_flist vNHvuwK  
biG :Xn  
    'Tracks how many files are found A,EuUp  
    Dim fCount As Long o@L2c3?c5  
    fCount = 0 >8|V[-H  
cB)tfS4)  
    'Recurse directory and search for text files M8R/a[ -A  
    Dim f As String O^n\lik  
    f = Dir$(in_dir & "*.txt") y&V%xE/  
    While f <> "" <v!jS=T  
        ReDim Preserve in_flist(fCount) pVM1%n:#  
        in_flist(fCount) = f :F_>`{  
        fCount += 1 ZnBGNr  
        f = Dir$() " {X0&  
    Wend z31g"  
    ReDim Preserve in_flist(fCount-1) 2sj: &][R  
nErr&{C  
End Sub EE*|#