Research Updates

On-chip single-photon sources are key components for integrated photonic quantum technologies. Semiconductor quantum dots can exhibit near-ideal single-photon emission, but this can be significantly degraded in on-chip geometries owing to nearby etched surfaces .....

Quantum photonics is a rapidly developing platform for future quantum network applications. Waveguide-based architectures, in which embedded quantum emitters act as both nonlinear elements to mediate photon–photon interactions and as highly coherent single-photon sources, offer a highly promising route to realize such networks .....

We study exciton polaritons in a two-dimensional Lieb lattice of micropillars. The energy spectrum of the system features two flat bands formed from S and Px;y photonic orbitals, into which we trigger bosonic condensation under high power excitation .....

Thin avalanche layers have been adopted to achieve low excess noise and high-gain bandwidth products in InP and InAlAs avalanche photodiodes. In this paper, we report the excess noise characterization in a series of Al1-xGaxAs0.56 Sb0.44 (x = 0, 0.05, 0.1, 0.15) diodes with avalanche layer thickness of 110-116 nm .....

Single photons and entangled photon pairs are a key resource of many quantum secure communication and quantum computation protocols, and non-Poissonian sources emitting in the low-loss wavelength region around 1,550nm are essential for the development of fibre-based quantum network infrastructure. However, reaching this wavelength window has been challenging for semiconductor-based quantum light sources .....

Compact semiconductor lasers with sub-wavelength-scale dimensions rely heavily on materials with low surface recombination due to the large surface area to volume ratios of their nano-cavities. Furthermore, the reliance on semiconductor nanostructures has led to predominantly bottom-up fabrication approaches, which has hindered scalable and practical applications. In this letter, we present lithographically constructed hybrid gap plasmon nanolasers using the gain of bulk GaAs operating at room temperature .....

Numerous applications would benefit from a compact laser source with tunable, continuous-wave emission in the deep ultraviolet (wavelengths <;250 nm); however, very few laser sources have been demonstrated with direct emission in this spectral region and options are generally limited to pulsed, fixed wavelength sources or complex and impractical setups for nonlinear frequency mixing of the emission of several infrared lasers in various external enhancement cavities .....

A controlled quantum system can alter its environment by feedback, leading to reduced-entropy states of the environment and to improved system coherence .....

Quantum cascade lasers can be efficient infrared radiation sources and consist of several hundreds of very thin layers arranged in stacks that are repeated periodically. Both the thicknesses of the individual layers as well as the period lengths need to be monitored to high precision .....

We report on the formation of a diverse family of transverse spatial polygon patterns in a microcavity polariton fluid under coherent driving by a blue-detuned pump. Patterns emerge spontaneously as a result of energy-degenerate polariton-polariton scattering from the pump state to interfering high-order vortex and antivortex modes, breaking azimuthal symmetry .....