Spatiotemporal bessel beams: theory and experiments.
We describe a family of dispersion-free and diffraction-free optical beams consisting in two-dimensional wave packets with a spatiotemporal Bessel (STB) profile propagating in media with anomalous dispersion. We also describe quasi-invariant optical beams with a spatiotemporal Bessel-Gauss (STBG) profile; these wave packets have finite dimensions and energy, conditions to be representative of physical beams. The paper provides a detailed account of the properties of STB and STBG beams, including their spatially resolved frequency spectrum, their far-field behaviour and a comparison of the propagation of STBG beams with that of Gaussian wave packets. An experimental setup based on a folded pulse shaper has allowed to generate STBG beams using the ultrashort pulses from a Ti:sapphire laser. The analysis of the spatially resolved frequency spectrum and of the spatial and temporal profiles obtained experimentally shows good agreement with theory.
Dallaire
Michaël
M
Centre d'Optique, Photonique et Laser Département de physique, de génie physique et d'optique, Université Laval, Québec, Qc, Canada, G1V 0A6.
McCarthy
Nathalie
N
Piché
Michel
M
D003198:Computer Simulation; D008027:Light; D008029:Lighting / Q000379:methods*; D008962:Models, Theoretical; D009391:Nephelometry and Turbidimetry / Q000379:methods*; D012542:Scattering, Radiation