Time-resolved high harmonic spectroscopy of dynamical symmetry breaking in bi-circular laser fields
arXiv:1707.05590 · doi:10.1364/OE.25.022880
Abstract
The bi-circular scheme for high harmonic generation, which combines two counter-rotating circular fields with frequency ratio 2:1, has recently permitted to generate high harmonics with essentially circular polarization, opening the way for ultrafast chiral studies. This scheme produces harmonic lines at 3N + 1 and 3N + 2 multiples of the fundamental driving frequency, while the 3N lines are forbidden owing to the three-fold symmetry of the field. It is generally established that the routinely observed signals at these forbidden harmonic lines come from a slight ellipticity in the driving fields, which breaks the three-fold symmetry. We find that this is neither the only nor it is the dominant mechanism responsible. The forbidden lines can be observed even for perfectly circular, long driving pulses. We show that they encode rich information on the sub-cycle electronic dynamics that occur during the generation process. By varying the time delay and relative intensity between the two drivers, we demonstrate that when the second harmonic either precedes or is more intense than the fundamental field, the dynamical symmetry of the system is broken by electrons trapped in Rydberg orbits (i.e., Freeman resonances), and that the forbidden harmonic lines are a witness of this.
References in corpus (12)
- Generation of phase-matched circularly-polarized extreme ultraviolet high harmonics for magnetic circular dichroism spectroscopy
- Attosecond dynamics through a Fano resonance: Monitoring the birth of a photoelectron
- A practical scheme for generating isolated elliptically polarized attosecond pulses using bi-chromatic counter rotating circularly polarized laser fields
- Relaxation Dynamics in Photoexcited Chiral Molecules Studied by Time-Resolved Photoelectron Circular Dichroism: Toward Chiral Femtochemistry
- Role of Excited States In High-order Harmonic Generation
- Circularly Polarized Molecular High Harmonic Generation Using a Bicircular Laser
- Opportunities for chiral discrimination using high harmonic generation in tailored laser fields
- Quantum mechanical approach to probing the birth of attosecond pulses using a two-color field
- High-order harmonic generation in polyatomic molecules induced by a bicircular laser field
- Even harmonic generation in isotropic media of dissociating homonuclear molecules
- Multidimensional high harmonic spectroscopy: A semi-classical perspective on measuring multielectron rearrangement upon ionization
- XUV lasing during strong-field assisted transient absorption in molecules
Cited by in corpus (9)
- Control of attosecond light polarization in two-color bi-circular fields
- Theory of entanglement and measurement in high harmonic generation
- Control of helicity of high-harmonic radiation using bichromatic circularly polarized laser fields
- Strong-field control and enhancement of chiral response in bi-elliptical high-order harmonic generation: an analytical model
- Controlling polarization of attosecond pulses with plasmonic-enhanced bichromatic counter-rotating circularly polarised fields
- Role of Spin-Orbit Coupling in High-order Harmonic Generation Revealed by Super-Cycle Rydberg Trajectories
- High-order harmonic generation from 2D periodic potentials in circularly and bichromatic circularly polarized laser fields
- Evidence of ac-Stark-shifted resonances in intense two-color circularly polarized laser fields
- Polarization control of attosecond pulses using bi-chromatic elliptically polarized laser