Tomographic Reconstruction of Circularly Polarized High Harmonic Fields: 3D Attosecond Metrology

Abstract

Bright, circularly polarized, extreme ultraviolet (EUV) and soft x-ray high-harmonic beams can now be produced using counter-rotating circularly polarized driving laser fields. Although the resulting circularly polarized harmonics consist of relatively simple pairs of peaks in the spectral domain, in the time domain, the field is predicted to emerge as a complex series of rotating linearly polarized bursts, varying rapidly in amplitude, frequency, and polarization. We extend attosecond metrology techniques to circularly polarized light by simultaneously irradiating a copper surface with circularly polarized high-harmonic and linearly polarized infrared laser fields. The resulting temporal modulation of the photoelectron spectra carries essential phase information about the EUV field. Utilizing the polarization selectivity of the solid surface and by rotating the circularly polarized EUV field in space, we fully retrieve the amplitude and phase of the circularly polarized harmonics, allowing us to reconstruct one of the most complex coherent light fields produced to date.

Helicity-Selective Enhancement and Polarization Control of Attosecond High Harmonic Waveforms Driven by Bichromatic Circularly Polarized Laser Fields

“…orders with opposite helicity (i.e., left-circular, LCP, or right-circular polarization, RCP) [25][26][27][28][29][30][31][32][33][34][35][36]. Moreover, the driving laser field parameters determine the spectral, temporal, and polarization properties of CPHHG, enabling the creation of tailored CPHHG waveforms.…”

“…The spectral control afforded by a bichromatic driving laser field also has direct consequences on the underlying temporal waveform generated during the CPHHG process. In the time domain, the presence of phase-locked harmonics with alternating helicities manifests as a train of attosecond bursts with exotic polarization properties [27,28,33,35,36,[45][46][47]. Under typical experimental conditions, the unique attosecond pulse trains (APTs) of CPHHG consist of linearly polarized bursts of EUV and soft x-ray radiation [29,30,39,45], each rotated in the polarization plane by an angle that depends on the central frequencies of the combined laser field [28,29,48].…”

High harmonic generation from axial chiral molecules

“…To avoid these problems, we adopt the BCCP laser fields. HHG from atoms and simple molecules driven by the BCCP laser fields has been widely studied [47][48][49]. With the BCCP pulses, the HHG efficiency will be dramatically increased and the cutoff can be also extended.…”

Ultrafast and nanoscale diodes

“…Future studies on ultrafast electron emission may include emission delay and scattered electron contributions, charge redistribution and thermalization (Pant & Ang 2013), field enhancement (Feng & Verboncoeur 2005, 2008Miller, Lau & Booske 2007;Feng, Verboncoeur & Lin 2008;Jensen et al 2008;Tang, Shiffler & Cartwright 2011) and space charge effects (Griswold, Fisch & Wurtele 2010;Pedersen et al 2010;Caflisch & Rosin 2012;Griswold et al 2012;Ilkov et al 2015;Rokhlenko 2015;Liu et al 2015a,b;Griswold & Fisch 2016), all under ultrafast conditions. It is important to link ultrafast strong-field laser physics in atoms and gaseous media to that in nanoclusters, solid-state surfaces and nanostructures (Corkum et al 1988;Corkum 1993;Corkum, Burnett & Ivanov 1994;Rundquist et al 1998;Corkum & Krausz 2007;Fan et al 2015;Chen et al 2016;. These studies would offer unprecedented scientific advances in attosecond science (Corkum & FIGURE 3.…”