Generation of a 2-dimensional Airy beam from a Gaussian laser beam.
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A two-dimensional Airy beam can be generated by substituting a cubic phase
distribution in a Gaussian beam followed by a Fourier transform by a positive lens.
In the simulation below we repeat the simulations published by
Latychevskaia et al. [#a1]_ and we compare the LightPipes simulation with their results.
.. rubric:: References:
.. [#a1] T. Latychevskaia, D. Schachtler, and H.W. Fink, "Creating Airy beams employing a transmissive spatial light modulator", Appl. Opt. 55, 6095-6101 (2016).
.. plot:: ./Examples/AiryBeam/2DAiryBeam.py
.. index::
Self-healing Airy beam
Self-healing Airy beam.
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In the video below we demonstrate the self-healing feature of Airy beams.
A 2 mm diameter disk is placed in the path of the main lobe at z = 40 cm. After disturbing the beam, the beam's shape recovers.
.. raw:: html
The video was made with the following python script:
.. code-block:: bash
"""
Self healing Airy beam. A disk is placed at some distance from the origin.
This obstacle disturbs the beam, but it heals itself.
"""
from LightPipes import *
import matplotlib.pyplot as plt
import matplotlib.animation as animation
wavelength = 2.3*um
size = 30*mm
N = 500
x0=y0=1*mm
a1=a2=0.1/mm
w=1*mm
z= 0 *cm
dz = 2 *cm
fig, ax = plt.subplots(); ax.axis('off')
ims =[]
F0=Begin(size,wavelength,N)
F0=AiryBeam2D(F0,x0=x0, y0=y0, a1=a1, a2=a2)
for i in range(1000):
if i == 20: # at z = 40 cm an obstacle is placed
F0=CircScreen(F0,w)
F=Fresnel(F0,z)
I=Intensity(F)
im = ax.imshow(I, animated = True, cmap='jet')
s = r'$z = {:4.0f}$ cm'.format(z/cm)
t = ax.annotate(s,(100,100), color = 'w') # add text
ims.append([im,t])
z += dz
ani = animation.ArtistAnimation(fig, ims, interval=5, blit=True,
repeat_delay=1000)
ani.save("movie.mp4")
plt.show()