6 results match your criteria: "University of Ottawa and National Research Council of Canada[Affiliation]"
Nat Commun
May 2019
Department of Physics, University of Ottawa, 25 Templeton St., Ottawa, ON, K1N 6N5, Canada.
Strong field laser physics has primarily been concerned with controlling beams in time while keeping their spatial profiles invariant. In the case of high harmonic generation, the harmonic beam is the result of the coherent superposition of atomic dipole emissions. Therefore, fundamental beams can be tailored in space, and their spatial characteristics will be imparted onto the harmonics.
View Article and Find Full Text PDFNat Commun
April 2017
Department of Physics, University of Ottawa, 25 Templeton St, Ottawa, Ontario, Canada K1N 6N5.
Optical vortices, which carry orbital angular momentum (OAM), can be flexibly produced and measured with infrared and visible light. Their application is an important research topic for super-resolution imaging, optical communications and quantum optics. However, only a few methods can produce OAM beams in the extreme ultraviolet (XUV) or X-ray, and controlling the OAM on these beams remains challenging.
View Article and Find Full Text PDFSci Rep
May 2016
Joint Attosecond Science Laboratory, University of Ottawa and National Research Council of Canada, 100 Sussex Dr, Ottawa K1A 0R6, Canada.
Phys Rev Lett
March 2014
Max-Planck Institute of Quantum Optics, Hans-Kopfermann-Strasse 1, D-85748 Garching, Germany and J. R. Macdonald Laboratory, Physics Department, Kansas State University, 116 Cardwell Hall, Manhattan, Kansas 66506, USA.
The transition between two distinct mechanisms for the laser-induced field-free orientation of CO molecules is observed via measurements of orientation revival times and subsequent comparison to theoretical calculations. In the first mechanism, which we find responsible for the orientation of CO up to peak intensities of 8 × 10(13) W/cm(2), the molecules are impulsively oriented through the hyperpolarizability interaction. At higher intensities, asymmetric depletion through orientation-selective ionization is the dominant orienting mechanism.
View Article and Find Full Text PDFPhys Rev Lett
December 2012
Joint Attosecond Science Laboratory, University of Ottawa and National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6, Canada.
We bring the methodology of orienting polar molecules together with the phase sensitivity of high harmonic spectroscopy to experimentally compare the phase difference of attosecond bursts of radiation emitted upon electron recollision from different ends of a polar molecule. This phase difference has an impact on harmonics from aligned polar molecules, suppressing emission from the molecules parallel to the driving laser field while favoring the perpendicular ones. For oriented molecules, we measure the amplitude ratio of even to odd harmonics produced when intense light irradiates CO molecules and determine the degree of orientation and the phase difference of attosecond bursts using molecular frame ionization and recombination amplitudes.
View Article and Find Full Text PDFPhys Rev Lett
September 2012
Joint Attosecond Science Laboratory, University of Ottawa and National Research Council of Canada, 100 Sussex Drive, Ottawa, ON K1A 0R6, Canada.
We produce oriented rotational wave packets in CO and measure their characteristics via high harmonic generation. The wave packet is created using an intense, femtosecond laser pulse and its second harmonic. A delayed 800 nm pulse probes the wave packet, generating even-order high harmonics that arise from the broken symmetry induced by the orientation dynamics.
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