Volume 13 Issue 8, August 2019

As a pioneer in the research on ultra-high-quality dielectric microresonators and their applications in nonlinear optics, frequency metrology and laser science, Mikhail Gorodetsky is badly missed.

Judicious scaling of the waveguide properties of a simple hollow capillary fibre filled with helium allows for powerful pulse temporal compression down to the sub-femtosecond level, further enabling the efficient generation of ultrafast ultraviolet light.

Modulation of light by external waves is an essential function in any photonics-based system. Using an integrated plasmonic approach, the speed of modulation of 1.55-μm waves has now been extended to the ‘low’ THz band.

Increased bandwidth and fluctuations are hurdles on the path towards generating intense fully coherent X-ray free-electron laser output. A recent experiment at FERMI Trieste demonstrated that these difficulties can be overcome by an approach called echo-enabled harmonic generation.

High-efficiency, time-domain, near-infrared fluorophores provide multiplexed colour channels for distinct deep bioimaging.

A high-speed wireless THz communication link is seamlessly integrated into a fibre-optic network. The demonstration relies on an ultra-broadband modulator exploiting two-dimensionally localized gap plasmons for direct conversion of the THz signals to the optical domain.

By time-shifting short-pulse excitation photon energy into prolonged luminescent emission in the time domain, both the number of light signal transducers in sub-15 nm nanoparticles and the near-infrared-in to near-infrared-out conversion efficiency can be maximized, advancing in vivo optical bioimaging.

The photo-instability of perovskite solar cells is investigated and controlled by the use of a passivation strategy.

The discovery of two deep-blue organic emitters of light could aid the development of next-generation organic light-emitting devices.

Optical soliton dynamics in large-core hollow capillary fibres is demonstrated. The findings enable the scaling of soliton effects by several orders of magnitude to the multi-millijoule energy and terawatt peak power levels, and open up opportunities for new-generation table-top light sources for ultrafast strong-field physics and advanced spectroscopy.

Echo-enabled harmonic generation in a free-electron laser enables 45th harmonic pulses from a 264 nm wavelength seed, yielding 5.9 nm wavelength coherent output.

The combined technique of dual-comb multi-heterodyne detection and Fourier-transform analysis allows simultaneous acquisition and monitoring of the phase pattern of a generic frequency comb demonstrating the high degree of coherence of the emission of two quantum cascade laser frequency combs.

The polarization structure around polarization singularities can exhibit arbitrary fractional rotations when tracing around the singularity, due to an underlying topology of a torus knot imprinted by the chosen ratio of frequencies contained in the light beam.

By combining a single-photon time-of-flight camera with computational processing of the spatial and full temporal photon distribution data, an object embedded inside a strongly diffusive medium can be imaged over more than 80 transport mean free paths in a contactless manner on the timescale of the order of 1 s.