Molded nonlinear light wave packets and applications
The nonlinear propagation of ultrashort laser pulses in the form of solitons, filaments and light bullets is an exciting research field [1]. Beyond the basic studies on the complex spatio-temporal phenomena involved, the field is driven significantly by its numerous applications, like for example in materials engineering, remote spectroscopy, but also for their use as powerful secondary sources across the electromagnetic spectrum [2]. Here we discuss our recent advances in molding the shape, temporal and spectral properties of filaments [3] and some corresponding applications enabled through these advances. We demonstrate how it becomes possible, for the first time after 20 years of research, to achieve localized and controlled modification of the index of refraction in the bulk of silicon [4]. This advance opens the way for laser processing in the exciting field of silicon photonics. We also discuss our recent advances in developing intense THz secondary sources using tailored laser filaments. We demonstrate that one may obtain powerful THz radiation using unconventional media, like liquids, where the medium presents strong linear absorption [5]. The mechanism responsible for this counterintuitive result is a phase locked second harmonic component in the filament that results in strong transient electron currents that radiate intense THz fields. Finally, we will also be discussing the way in achieving extreme THz electric and magnetic fields, in excess of GV/cm and kilo-Tesla strengths respectively, using intense two-color mid-infrared filaments [6,7].
[1] P. Panagiotopoulos et al., Nat. Commun. 4, 2622 (2013)
[2] K. Liu et al., Optica 3, 605-608 (2016)
[3] A. D. Koulouklidis et al., Phys. Rev. Lett. 119, 223901 (2017)
[4] M. Chanal et al., Nat. Commun. 8, 773 (2017)
[5] I. Dey et al., Nat. Commun. 8, 1184 (2017)
[6] V. Fedorov and S. Tzortzakis, Phys. Rev. A 97, 063842 (2018)
[7] V. Y. Fedorov, and S. Tzortzakis, Opt. Express 26, 31150-31159 (2018)