When solids are exposed to intense laser fields whose forces are comparable to the binding
forces of valence electrons in crystals, nonlinear optics of solids advances to the …

High-harmonic generation in atomic gases has been studied for decades, and has formed
the basis of attosecond science. Observation of high-order harmonics from bulk crystals was …

Recent progress in high power ultrafast short-wave and mid-wave infrared lasers has
enabled gas-phase high harmonic generation (HHG) in the water window and beyond, as …

The electronic properties of graphene can give rise to a range of nonlinear optical
responses. One of the most desirable nonlinear optical processes is high-harmonic …

High-harmonic generation (HHG) in bulk solids permits the exploration of materials in a new
regime of strong fields and attosecond timescales,,,,,. The generation process has been …

High-harmonic generation (HHG) in solids has emerged in recent years as a rapidly
expanding and interdisciplinary field, attracting attention from both the condensed-matter …

The microscopic valence electron density determines the optical, electronic, structural and
thermal properties of materials. However, current techniques for measuring this electron …

Strong-field laser excitation of solids can produce extremely nonlinear electronic and optical
behaviour. As recently demonstrated, this includes the generation of high harmonics …

Valence electrons contribute a small fraction of the total electron density of materials, but
they determine their essential chemical, electronic and optical properties. Strong laser fields …

The advent of visible-infrared laser pulses carrying a substantial fraction of their energy in a
single field oscillation cycle has opened a new era in the experimental investigation of …