Free-electron interaction with nonlinear optical states in microresonators.

The short de Broglie wavelength and strong interaction empower free electrons to probe structures and excitations in materials and biomolecules. Recently, electron-photon interactions have enabled new optical manipulation schemes for electron beams. In this work, we demonstrate the interaction of electrons with nonlinear optical states inside a photonic chip-based microresonator.

Metabolism of Acetaminophen by Enteric Epithelial Cells Mitigates Hepatocellular Toxicity In Vitro.

The gut-liver axis is defined by dietary and environmental communication between the gut, microbiome and the liver with its redox and immune systems, the overactivation of which can lead to hepatic injury. We used media preconditioning to mimic some aspects of the enterohepatic circulation by treating the human Caco-2 intestinal epithelial cell line with 5, 10 and 20 mM paracetamol (N-acetyl-para-aminophenol; APAP) for 24 h, after which cell culture supernatants were transferred to differentiated human hepatic HepaRG cells for a further 24 h. Cell viability was assessed by mitochondrial function and ATP production, while membrane integrity was monitored by cellular-based impedance.

Exposure and awareness of oral and maxillofacial surgery for first degree medical undergraduates in the United Kingdom.

Most of the current oral and maxillofacial surgery (OMFS) specialty trainees in the United Kingdom (UK) remain as those who first undertook a degree in dentistry. However, OMFS is an increasingly popular career choice amongst 'first degree' medical school graduates. The UK medical school curriculum should reflect this trend by ensuring that there is sufficient teaching and exposure to allow medical students to make informed career choices.

Cavity-mediated electron-photon pairs.

Quantum information, communication, and sensing rely on the generation and control of quantum correlations in complementary degrees of freedom. Free electrons coupled to photonics promise novel hybrid quantum technologies, although single-particle correlations and entanglement have yet to be shown. In this work, we demonstrate the preparation of electron-photon pair states using the phase-matched interaction of free electrons with the evanescent vacuum field of a photonic chip-based optical microresonator.

The Health-Related Quality of Life of Patients Waiting for Anterior Cruciate Ligament Reconstruction Is Worse Than an Age- and Sex-Matched Population: Increasing Time on Waiting List for Surgery Was Independently Associated with a Worse Quality of Life.

Background: The aims of this study were to assess the health-related quality of life (HRQoL) of patients awaiting anterior cruciate ligament (ACL) reconstruction compared to the population at risk: whether knee-specific function was predictive of HRQoL and to identify factors associated with a worse HRQoL.

Methods: Sixty-seven patients (male,  = 50; female,  = 17; mean age, 29) identified from the surgical waiting list completed a questionnaire that included demographics, BMI, time of injury, EuroQol 5-dimension (EQ-5D), Short-Form (SF-36), and International Knee Documentation Committee (IKDC) scores. Age- and sex-matched HRQoL data were obtained from population level data.

Integrated photonics enables continuous-beam electron phase modulation.

Integrated photonics facilitates extensive control over fundamental light-matter interactions in manifold quantum systems including atoms, trapped ions, quantum dots and defect centres. Ultrafast electron microscopy has recently made free-electron beams the subject of laser-based quantum manipulation and characterization, enabling the observation of free-electron quantum walks, attosecond electron pulses and holographic electromagnetic imaging. Chip-based photonics promises unique applications in nanoscale quantum control and sensing but remains to be realized in electron microscopy.

High-yield, wafer-scale fabrication of ultralow-loss, dispersion-engineered silicon nitride photonic circuits.

Low-loss photonic integrated circuits and microresonators have enabled a wide range of applications, such as narrow-linewidth lasers and chip-scale frequency combs. To translate these into a widespread technology, attaining ultralow optical losses with established foundry manufacturing is critical. Recent advances in integrated SiN photonics have shown that ultralow-loss, dispersion-engineered microresonators with quality factors Q > 10 × 10 can be attained at die-level throughput.

Low-Loss Integrated Nanophotonic Circuits with Layered Semiconductor Materials.

Monolayer transition-metal dichalcogenides with direct bandgaps are emerging candidates for optoelectronic devices, such as photodetectors, light-emitting diodes, and electro-optic modulators. Here we report a low-loss integrated platform incorporating molybdenum ditelluride monolayers with silicon nitride photonic microresonators. We achieve microresonator quality factors >3 × 10 in the telecommunication O- to E-bands.

Reconfigurable radiofrequency filters based on versatile soliton microcombs.

The rapidly maturing integrated Kerr microcombs show significant potential for microwave photonics. Yet, state-of-the-art microcomb-based radiofrequency filters have required programmable pulse shapers, which inevitably increase the system cost, footprint, and complexity. Here, by leveraging the smooth spectral envelope of single solitons, we demonstrate microcomb-based radiofrequency filters free from any additional pulse shaping.

Monolithic piezoelectric control of soliton microcombs.

High-speed actuation of laser frequency is critical in applications using lasers and frequency combs, and is a prerequisite for phase locking, frequency stabilization and stability transfer among optical carriers. For example, high-bandwidth feedback control of frequency combs is used in optical-frequency synthesis, frequency division and optical clocks. Soliton microcombs have emerged as chip-scale frequency comb sources, and have been used in system-level demonstrations.

Chip-based soliton microcomb module using a hybrid semiconductor laser.

Photonic chip-based soliton microcombs have shown rapid progress and have already been used in many system-level applications. There has been substantial progress in realizing soliton microcombs that rely on compact laser sources, culminating in devices that only utilize a semiconductor gain chip or a self-injection-locked laser diode as the pump source. However, generating single solitons with electronically detectable repetition rates from a compact laser module has remained challenging.

Observation of Stimulated Brillouin Scattering in Silicon Nitride Integrated Waveguides.

Silicon nitride (Si_{3}N_{4}) has emerged as a promising material for integrated nonlinear photonics and has been used for broadband soliton microcombs and low-pulse-energy supercontinuum generation. Therefore, understanding all nonlinear optical properties of Si_{3}N_{4} is important. So far, only stimulated Brillouin scattering (SBS) has not yet been reported.

Author Correction: Electrically pumped photonic integrated soliton microcomb.

The original version of this Article contained an error in the first sentence of the Acknowledgements, which incorrectly read 'This publication was supported by Contract HR0011-15-C-0055 (DODOS) from the Defense Advanced Research Projects Agency (DARPA), Defense Sciences Office (DSO).' The correct version states 'Microsystems Technology Office (MTO)' in place of 'Defense Sciences Office (DSO)'. This has been corrected in both the PDF and HTML versions of the Article.

Double inverse nanotapers for efficient light coupling to integrated photonic devices.

Efficient light coupling to integrated photonic devices is of key importance to a wide variety of applications. "Inverse nanotapers" are widely used, in which the waveguide width is reduced to match an incident mode. Here, we demonstrate novel "double inverse" tapers, in which we reduce both the waveguide height and width.