Volume 16 Issue 6, June 2022

Nature Photonics spoke to Hillel Adesnik from UC Berkeley about the benefits of using photonic techniques in optogenetics and the key challenges laying ahead.

A single-pass free electron laser operating at 0.16 THz with an energy efficiency of ~10% promises compact and high-power sources in the terahertz spectral region.

High-harmonics spectroscopy reveals the closure of the bandgap between adjacent conduction bands in solids driven by high-intensity laser fields, providing insight into light-driven modifications of band structures

The strongly temperature-dependent band-edge absorption from gallium arsenide enables an optical thermometer with nanokelvin temperature resolution and microscale spatial resolution.

Progress in generating and harnessing high harmonics in solid-state media is reviewed.

A microscale optical thermometer with nanokelvin sensitivity makes use of the temperature dependence of the band-edge absorption in GaAs.

Modifications of the effective band structure of MgO crystal is investigated on a timescale within one-quarter cycle of the electromagnetic-field oscillation. The high-harmonic generation spectra show a signature of laser-induced closing of the bandgap.

Researchers show that up-conversion in manganese-doped CdSe colloidal quantum dots enables efficient electron photoemission. The effect is exploited for high-yield production of solvated electrons, demonstrating photochemistry applicability.

A single-pass free-electron laser based on a waveguide in a tapered helical undulator is developed. The energy conversion efficiency from a relativistic electron beam to terahertz waves at 0.16 THz is ~10%.

Microstructured optical fibre is shown to be able transmit high-power laser light over long distances with high throughput efficiency.

Researchers demonstrate systems in which optical solitons coexist and interact with topological solitonic structures localized in the molecular alignment field of a soft birefringent medium. The findings could lead to solitonic tractor beams and new light–matter self-patterning phenomena.

An imaging scheme that employs raster-scanned active focusing can image hidden, non-line-of-sight objects

It is shown that rhombohedral stacked MoS₂ can enable scalable photovoltaic effects induced by spontaneous polarization throughout few-micrometre-sized exfoliated flakes. This is exploited in a graphene–MoS₂-based photovoltaic device.