Monday, February 11, 2019

Abstract-Analysis of terahertz generation using tilted pulse fronts


Koustuban Ravi and Franz Kärtner


Fig. 1 A tilted-pulse-front setup comprised of a diffraction grating and an imaging system. The angularly dispersed pulse produces a tilted pulse front (red ellipse) with tilt angle γ, resulting in terahertz radiation propagating at an angle γ with respect to the direction of pump pulse propagation.


https://www.osapublishing.org/oe/abstract.cfm?uri=oe-27-3-3496

A spatio-temporal analysis of terahertz generation by optical rectification of tilted pulse fronts is presented. Closed-form expressions of terahertz transients and spectra in two spatial dimensions are furnished in the undepleted limit. Importantly, the analysis incorporates spatio-temporal distortions of the optical pump pulse such as angular dispersion, group velocity dispersion due to angular dispersion, spatial and temporal chirp, as well as beam curvature. The influence of the radius of curvature on the tilt angle is shown. Furthermore, the impact of group velocity dispersion due to angular dispersion on terahertz frequency, conversion efficiency and peak field is revealed. In particular, the deterioration of terahertz frequency, efficiency and field at large pump bandwidths and beam sizes by group velocity dispersion due to angular dispersion is expressed analytically.
© 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

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