Volume 14 Issue 8, August 2020

A correlation method that combines ultrasound and fluorescence enables imaging in strongly scattering environments.

The finding that hollow-core optical fibres can preserve the state of linearly polarized light over hundreds of metres with exceptional purity could benefit applications in sensing, gyroscopes and quantum optics.

New methods to control how laser pulses propagate inside a plasma could signify the start of a global race to demonstrate truly high-energy compact particle accelerators.

A phase transition between disordered and quasi-ordered states, known as the Berezinskii–Kosterlitz–Thouless transition, has now been revealed in a two-dimensional photonic ‘fluid’. The interplay between phase singularities and coherence may lead to new vortex-based optical applications.

Independent velocity and intensity control of photons for driving a laser-plasma accelerator may enable a dephasing-free regime.

Observations of decoherence from thermodynamic noise in microresonator soliton frequency combs and laser cooling that reduces soliton thermal decoherence to far below the ambient-temperature limit are described, linking nonlinear photonics and microscopic fluctuations.

Nanophotonic microwave synthesizers in the X-band (10 GHz, for radar) and K-band (20 GHz, for 5G), based on integrated soliton microcombs driven by a low-noise fibre laser, link the fields of microwave photonics and integrated microcombs.

By suppressing the second- and third-order intracavity dispersion using an intracavity spectral pulse shaper, a mode-locked laser that emits pure-quartic soliton pulses that arise from the interaction of the fourth-order dispersion and the Kerr nonlinearity is demonstrated.

A metasurface laser generates orbital angular momentum states with quantum numbers reaching ℓ = 100. Simultaneous output vortex beams, with Δℓ as great as 90, are demonstrated in the visible regime.

Carefully designed hollow-core antiresonant fibres support a pair of orthogonal polarization modes with a level of purity and cross-coupling that is orders of magnitude lower than other fibre designs and beyond the fundamental Rayleigh scattering limit of glass core fibres.

Combining the advantages of ultrasound and light for fluorescence imaging, an imaging technique termed fluorescence and ultrasound-modulated light correlation, or FLUX, that leverages the dynamic nature of the medium is reported to uniquely resolve fluorophore distribution even when the speckles decorrelate fast.

A topological transition in a nonlinear photonic lattice results in new vortex dynamics and a change from photonic fluid behaviour to that of a plasma-like gas.