Volume 14 Issue 5, May 2020

Dark-field microscopy is a widely used imaging method that emphasizes sharp edges and other small features, but typically requires specialized microscope components. Researchers have now engineered special substrates that enable dark-field microscopy using simple bright-field microscopes.

Using a photonic crystal slab combined with a conventional optical imaging system, a two-dimensional optical image differentiator is experimentally demonstrated for edge detection.

Exciton funnelling due to non-homogeneous strain was previously thought of as an efficient neutral exciton transport mechanism. New findings suggest that exciton funnelling might be negligible compared with another strain-dependent process, the conversion of neutral excitons into trions.

Delegates at the BiOS symposium heard how artificial intelligence can transform medical imaging, with its ability to improve quality, speed and molecular specificity.

This Review covers recent progress in integrated quantum photonics (IQP) technologies and their applications. The challenges and opportunities of realizing large-scale, monolithic IQP circuits for future quantum applications are discussed.

The Review summarizes the progress of hybrid quantum photonics integration in terms of its important design considerations and fabrication approaches, and highlights some successful realizations of key physical resources for building integrated quantum devices, such as quantum teleporters, quantum repeaters and quantum simulators.

An organic solar cell designed with minimal energetic disorder exhibits very low energy loss due to non-radiative recombination and highly efficient operation.

A heralded squeezing gate with near unit fidelity is demonstrated, even for modest ancillary squeezing. A heralding filter is implemented in the feed-forward operation. With 6 dB of ancillary squeezing, a fidelity of 0.985 is experimentally obtained.

A luminescent photonic substrate with a controlled angular emission profile is introduced and its ability to generate high-contrast dark-field images of micrometre-sized living organisms is demonstrated using standard optical microscopy equipment.

Vertical integration of a metalens to realize compound nanophotonic systems for optical analog image processing is realized, significantly reducing the size and complexity of conventional optical systems.

The photoluminescence spectrum of WS₂ is modified under strain applied by an atomic force microscope probe. The free carrier redistribution yields conversion of excitons to trions with conversion efficiency approaching 100%.

Monolithic photonics devices based on SiC are fabricated by a wafer bonding and thinning technique. The strong enhancement of single-photon emission from a colour centre and optical frequency conversion with an efficiency of 360% W⁻¹ are demonstrated.