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arXiv · 1710.09889

Pulse shaping in the terahertz frequency range for the control of photo-excited carriers in graphene

Denis Gagnon·Joey Dumont·François Fillion-Gourdeau·Steve MacLean
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Abstract

The shape of a few-cycle terahertz (THz) laser pulse can be optimized to provide control over conduction band populations in graphene. To demonstrate this control in a theoretical way, a spectral parametrization of the driving pulse using $B$-splines is used in order to obtain experimentally realistic pulses of bandwidth $\sim$ 30 THz. Optimization of the spectral shape is performed via differential evolution, using the $B$-splines expansion coefficients as decision variables. Numerical results show the possibility of changing the carrier density in graphene by a factor of 4 for a fixed pulse energy. In addition, we show that it is possible to selectively suppress or enhance multi-photon absorption features by optimizing over narrow windows in reciprocal space. The application of pulse shaping to the control of scattering mechanisms in graphene is also discussed.

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Denis Gagnon, Joey Dumont, François Fillion-Gourdeau, Steve MacLean. 2017-10-26. Pulse shaping in the terahertz frequency range for the control of photo-excited carriers in graphene. https://doi.org/10.1364/josab.35.003021

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