Volume 14 Issue 11, November 2020

Photoluminescence spectroscopy using atomic-scale light reveals an optical transition of a single molecule at sub-nanometre resolution.

Facilities generating coherent X-rays tend to be large scale and costly. Now researchers have demonstrated a parametric and coherent laboratory-scale X-ray source by passing moderately energetic electrons through van der Waals heterostructures.

The limited control of electrons by light has resulted in photonic-driven circuits lagging far behind their electronic counterparts. Now, a technique exploiting coherent control with structured light has been used to sculpt the spatial distribution of electric currents, ushering in vectorized optoelectronic control in semiconductors.

An experimental study of the second-harmonic-generation process in a beta barium borate crystal shows that homogeneous optical crystals can exhibit the rich physics of the spin–orbit angular momentum cascade in the nonlinear optical regime.

Moiré lattices optically induced in photorefractive nonlinear media are used to explain the formation of optical solitons under different geometrical conditions controlled by the twisting angle between the constitutive sublattices.

A method to tune pseudo-magnetic fields for polaritons on a strained metasurface is demonstrated.

Deactivation of deep-strong light–matter coupling is achieved by femtosecond switching of terahertz cavities. This disruption leads to pronounced high-frequency polarization oscillations evolving much faster than the oscillation cycle of light.

Engineering of the spatial distribution of currents in a semiconductor is demonstrated using vectorial arrangement of optical fields, enabling an ultrafast magnetic field source.

Tunable X-ray generation, from ultrathin van der Waals materials impacted by relativistic electrons, is demonstrated.

Through the use of a plasmon-active atomically sharp tip and an ultrathin insulating film, and precise junction control in a highly confined nanocavity plasmon field at the scanning tunnelling microscope junction, sub-nanometre-resolved single-molecule near-field photoluminescence imaging with a spatial resolution down to ∼8 Å is achieved.

A strong Brillouin amplification per unit length, observed in a gas-filled hollow-core fibre, is used to realize a low-threshold continuous-wave single-frequency laser that can in principle operate at any wavelength and to demonstrate distributed temperature sensing with no strain cross-sensitivity.