Light bullet
Light bullets are localized pulses of electromagnetic energy that can travel through a medium and retain their spatiotemporal shape in spite of diffraction and dispersion which tend to spread the pulse. This is made possible by a balance between the non-linear self-focusing and spreading effects brought about by the medium in which the pulse beam propagates.[1]
Prediction and Discovery
Light bullets were predicted and so termed by Yaron Silberberg in 1990,[2] and demonstrated the following decade.
Comparison with solitons
Spatial and temporal stability which are the characteristics of a soliton have been achieved in light bullets using alternative refractive index models. An experiment which exploited the discrete spreading and self-focusing effects on 170-femtosecond pulses at 1550-nanometre wavelengths by a two-dimensional hexagonal array of silica waveguides reported a spatial profiles stationary for about twice as far as it would be in linear propagation and temporal profile about nine times stationary as that of the corresponding linear propagation.[3]
Light bullets lose energy in the process of a collision. This behavior is different from that of solitons which survive collisions without losing energy[4]
References
- "Viewpoint: Generation of light bullets". Cite journal requires
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(help) - Silberberg, Yaron (1990-11-15). "Collapse of optical pulses". Optics Letters. 15 (22): 1282–4. Bibcode:1990OptL...15.1282S. doi:10.1364/OL.15.001282. ISSN 1539-4794. PMID 19771066.
- "Viewpoint: Generation of light bullets". Cite journal requires
|journal=
(help) - "Light bullets".
- "Laser Triggers Lightning "Precursors" in Clouds".
- "Laser "Light Bullets" Made to Curve".