Volume 15 Issue 2, February 2021

Nature Photonics spoke to Aydogan Ozcan about the rise of artificial intelligence-enabled optics and the hurdles ahead.

A method to quantitatively map transient electromagnetic waveforms with atomic-spatial resolution is now possible using lightwave-driven scanning tunnelling microscopy featuring a single-molecule switch.

Electromagnetic fields in light waves are mainly transverse to propagation direction but actually also have longitudinal components, which may give rise to unexpected optical phenomena involving the angular momentum of light, such as transverse spin and optical torques.

A network of quantum sensors for estimating phase shifts is shown to operate with superior sensitivity when delocalized highly entangled states are employed.

The application of deep learning to the design of photonic structures and devices is reviewed, including algorithm fundamentals.

The potential of machine-learning application to the field of ultrafast photonics is reviewed, with key examples including pulsed lasers, and control and characterization of ultrafast propagation dynamics.

Photonics offers an attractive platform for implementing neuromorphic computing due to its low latency, multiplexing capabilities and integrated on-chip technology.

Sculpting and focusing femtosecond cylindrical vector vortex pulses by a slit allows the controllable transformation of the photon’s orbital angular momentum into spin angular momentum, which can be characterized in situ by a strong-field ionization experiment.

Researchers demonstrate vectorial optomechanical effects using a nematic liquid crystal and report creation of multiple self-induced lenses from a single beam.

An epsilon-near-zero medium is used to demonstrate ultrastrong coupling between phonons and gap plasmons. The approach may pave the path to exploitation of vibrational transitions.

By combining a photoinduced effective χ⁽²⁾ nonlinearity with resonant enhancement and perfect phase matching in a silicon nitride microring resonator, second-harmonic generation with milliwatt-level output powers with up to 22 ± 1% power conversion efficiency is demonstrated.

Distributed quantum metrology is demonstrated for both individual and averaged phase shifts by using discrete-variable entangled photons. An error reduction of 4.7 dB below the shot-noise limit is achieved when a total number of photon passes is 21.

Ultrafast lightwave sampling based on scanning tunnelling microscopy is developed to resolve near fields with sub-picosecond time resolution and sub-nanometre spatial resolution. Parameter-free quantitative measurement is achieved by using a single-molecule switch.

Guanidinium doping is shown to enhance the operation of perovskite nanocrystal light-emitting diodes.

A theoretical and experimental study of the transverse spin appearing in non-paraxial light when the source is totally unpolarized is reported, in sharp contrast to the usual longitudinal spin, which is directly related to the 2D polarization and vanishes in unpolarized fields.