In nonlinear optics, filament propagation is propagation of a beam of light through a medium without diffraction. This is possible because the Kerr effect causes an index of refraction change in the medium, resulting in self-focusing of the beam.[1]
Filamentary damage tracks in glass caused by laser pulses were first observed by Michael Hercher in 1964.[2] Filament propagation of laser pulses in the atmosphere was observed in 1994 by Gérard Mourou and his team at University of Michigan. The balance between the self-focusing refraction and self-attenuating diffraction by ionization and rarefaction of a laser beam of terawatt intensities, created by chirped pulse amplification, in the atmosphere creates "filaments" which act as waveguides for the beam thus preventing divergence. Competing theories, that the observed filament was actually an illusion created by an axiconic (bessel) or moving focus instead of a "waveguided" concentration of the optical energy, were put to rest by workers at Los Alamos National Laboratory in 1997.[3] Though sophisticated models have been developed to describe the filamentation process, a model proposed by Akozbek et al.[4] provides a semi-analytical and easy to understand solution for the propagation of strong laser pulses in the air.
Filament propagation in a semiconductor medium can also be observed in large aperture vertical cavity surface emitting lasers.
^Rashidian Vaziri, M R (2013). "Describing the propagation of intense laser pulses in nonlinear Kerr media using the ducting model". Laser Physics. 23 (10): 105401. Bibcode:2013LaPhy..23j5401R. doi:10.1088/1054-660X/23/10/105401. S2CID 250912159.
^Hercher, M. (1964). "Laser-induced damage in transparent media". Journal of the Optical Society of America. 54: 563.
^Xhao, X.M.; Jones, R.J.; Strauss, C.E.M.; Funk, D.J.; Roberts, J.P.; Taylor, A.J. (1997). "Control of femtosecond pulse filament formation in air through variation of the initial chirp of the pulse". CLEO '97., Summaries of Papers Presented at the Conference on Lasers and Electro-Optics. Vol. 11. IEEE. pp. 377–8. doi:10.1109/CLEO.1997.603294. ISBN 0-7803-4125-2. S2CID 120016673.
In nonlinear optics, filamentpropagation is propagation of a beam of light through a medium without diffraction. This is possible because the Kerr effect...
part of the conducting medium Filament propagation, diffractionless propagation of a light beam 3D printing filament, used as raw material in 3D printing...
Propagation then proceeds in a series of repeated focusing and defocusing steps. Jeffree cell, an early acousto-optic modulator Filamentpropagation Rapatronic...
gain medium would instantly self-focus and form a plasma or cause filamentpropagation, both of which would ruin the original beam's desirable qualities...
This is an index to articles about terms used in discussion of radio propagation. Contents: Top 0–9 A B C D E F G H I J K L M N O P Q R S T U V W X Y...
propagation regime, and described the theoretical context in which this phenomenon can be explained and controlled. Refer to main article on filament...
Magnetoelastic filaments are one-dimensional composite structures that exhibit both magnetic and elastic properties. Interest in these materials tends...
can result in the self-assembly of tangles of paired helical filaments and straight filaments, which are involved in the pathogenesis of Alzheimer's disease...
ion nitriding Ferrofluid Field line Field-reversed configuration Filamentpropagation Finite-difference time-domain method Fire Fisher's equation Fission...
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times as much power per unit area. An object at the temperature of the filament in an incandescent light bulb—roughly 3000 K, or 10 times room temperature—radiates...
^{2}u}{\partial z^{2}}}\right)+{\frac {1}{k}}q.} For example, a tungsten light bulb filament generates heat, so it would have a positive nonzero value for q when turned...
the main filament, from which lateral filaments grow radially. From the cortex filaments situated on the internodes, intercortical filaments also arise...
optimizing their shape, size, and distribution to direct and control crack propagation. This approach enhances fracture toughness, paving the way for the creation...
populated by intermittent coronal structures known as solar prominences or filaments. The Sun's corona lies above the chromosphere and extends millions of...
beyond the horizon, following the contour of the Earth. This mode of propagation, called ground wave, is the main mode in the LF band. Ground waves must...
mediated by the combination of vibrations and collisions of molecules, propagation and collisions of phonons, and diffusion and collisions of free electrons...
Biological evolution created hygroscopic solutions for water harvesting, filament tensile strength, bonding and passive motion – natural solutions being...