File:Focus vs NA.gif
Jump to navigation
Jump to search
No higher resolution available.
Focus_vs_NA.gif (480 × 480 pixels, file size: 2.18 MB, MIME type: image/gif, looped, 32 frames, 3.2 s)
Captions
Captions
Size and shape of a focus in 2D as a function of the NA
Summary
[edit]
| Description |
English: The quality of the focus you can create depends on the numerical aperture (NA) you are using (i.e. how many directions your waves are coming from). |
| Date | |
| Source | https://twitter.com/j_bertolotti/status/1268528338487910402 |
| Author | Jacopo Bertolotti |
| Permission (Reusing this file) |
https://twitter.com/j_bertolotti/status/1030470604418428929 |
Mathematica 12.0 code
[edit]
\[Lambda] = 1;
k0 = (2 \[Pi])/\[Lambda];
\[Alpha] = 4/(k0^2 I);
\[Sigma] = (k0^3 Norm[\[Alpha]]^2)/4;
G[r_] := N[I/4 HankelH1[0, k0 Norm[r] ]];
ReMapC[x_] := RGBColor[(Cos[2 \[Pi] x] + 1)/2 UnitStep[x - 0.5], 0, (Cos[2 \[Pi] x] + 1)/2 UnitStep[0.5 - x]];
p0 = Table[
sources = Table[5 \[Lambda] {-Cos[\[Theta]], Sin[\[Theta]]}, {\[Theta], -\[Theta]max, \[Theta]max, \[Pi]/30}];
nsources = Dimensions[sources][[1]];
DensityPlot[ Re[Sum[G[{x, y} - sources[[j]]], {j, 1, nsources}] ], {x, -10, 10}, {y, -10, 10}, PlotPoints -> 100, ColorFunction -> ReMapC, Frame -> False, PlotRange -> All,
RegionFunction -> Function[{x, y}, And @@ Table[Norm[{x, y} - sources[[j]]] > 0.2, {j, 1, nsources}] ]
, Epilog -> { Black, Thick, Table[Circle[sources[[j]], 0.2], {j, 1, nsources}], White, Text[Style[StringForm["NA=``", NumberForm[N[Sin[\[Theta]max]], {3, 2}]], Bold, FontSize -> 16], {-7, 8}]}]
, {\[Theta]max, 0, \[Pi]/2, \[Pi]/30}];
ListAnimate[p0]
Licensing
[edit]
I, the copyright holder of this work, hereby publish it under the following license:
 
|
This file is made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication. |
| The person who associated a work with this deed has dedicated the work to the public domain by waiving all of their rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law. You can copy, modify, distribute and perform the work, even for commercial purposes, all without asking permission.
|
File history
Click on a date/time to view the file as it appeared at that time.
| Date/Time | Thumbnail | Dimensions | User | Comment | |
|---|---|---|---|---|---|
| current | 12:16, 5 June 2020 | | 480 × 480 (2.18 MB) | Berto (talk | contribs) | Uploaded own work with UploadWizard |
You cannot overwrite this file.
File usage on Commons
There are no pages that use this file.
