Temporal superoscillations of subterahertz coherent acoustic phonons

Brehm, Simon; Akimov, A. V.; Campion, R. P.; Kent, A. J.

doi:10.1103/physrevresearch.2.023009

Cited by 6 publications

(2 citation statements)

References 32 publications

(36 reference statements)

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“…In parallel, the phenomenon of super-oscillations, mathematically described by a band-limited function that can oscillate, locally, with a frequency higher than the highest frequency of its Fourier spectrum [20,21], has raised a great deal of physical and mathematical interesting and intriguing implications [22][23][24][25][26][27][28]. Indeed, in Ref.…”

Section: Introductionmentioning

confidence: 99%

Principal frequency, super-bandwidth, and low-order harmonics generated by super-oscillatory pulses

Neyra¹,

Biasetti²,

Videla³

et al. 2022

Preprint

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An alternative definition to the main frequency of an ultra-short laser pulse, named principal frequency (ωP ), was recently introduced in E.G. Neyra, et al. Phys. Rev. A 103, 053124 (2021), resulting in a more transparent description of the nonlinear dynamics of a system driven by this coherent source. In this work, we extend the definition of ωP incorporating the spectral phase of the pulse. This upgraded definition allow us to deal with super-oscillatory pulses as well as to characterize sub-cycle pulses with a complex spectral content. Simultaneously, we study the nonlinear interaction between a few-cycle super-oscillatory pulse with a gaseous system, analysing the spectral characteristics of the fundamental, third and fifth harmonics. Here, we make use of an ab-initio quantum mechanical approach, supplemented with a wavelet analysis. We show that the spectral characteristics of the low-order harmonics are very well explained in terms of ωP , as well as the effective bandwidth of the super-oscillatory pulse. Our findings reinforce previous results that showed an increase of the effective bandwidth in the super-oscillatory region and the possibility to generate unique frequencies by a linear synthesis. We open, thus, not only new perspectives in ultrafast optics, exploring novel pathways towards the generation of fully tunable strong and short coherent sources, but also discuss possible extensions of the concepts presented here to other wave phenomena, that can be found in acoustics, signal processing or quantum mechanics.

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Section: Introductionmentioning

confidence: 99%

Principal frequency, super-bandwidth, and low-order harmonics generated by super-oscillatory pulses

Neyra¹,

Biasetti²,

Videla³

et al. 2022

Preprint

View full text Add to dashboard Cite

show abstract

“…This raises the tantalising possibility that nanoscale imaging with visible light may be made possible by superoscillation [43]. In the temporal domain THz acoustic superoscillations have been observed in superlattices [44], while the envelopes of laser pulses have been manipulated to display superoscillatory behaviour (relative to the envelope frequency) [45,46]. Up to this point however, there has been no direct observation of a time domain THz optical superoscillation, despite the availability of THz radiation which can be both characterised and manipulated in the time domain [47].…”

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confidence: 99%