Tunable Mie resonance in complex-shaped gadolinium niobate.

Nanoscale particles described by Mie resonance in the UV-vis-NIR region are in high demand for optical applications. Controlling the shape and size of these particles is essential, as it results in the ability to control the wavelength of the Mie resonance peak. In this work, we study the extensive scattering properties of gadolinium niobate particles with complex bar- and cube-like shapes in the UV-vis-NIR region.

Effective Michelson interference observed in fiber-optical analogue of Hawking radiation.

We experimentally observe the stimulated analogue of Hawking radiation produced in a photonic-crystal fiber, with a pulsed pump and a continuous-wave probe. In particular, we propose and demonstrate an innovative method to boost the efficiency and probe the coherence characteristics of the analogue Hawking effect relying on a double pump pulse with a controlled temporal delay. We show that the emitted analogue Hawking radiation corresponds to the coherently-added, interfering Hawking signals resulting from the probe interacting with each pump pulse.

Frequency and polarization emission properties of a photon-pair source based on a photonic crystal fiber.

In this work, we experimentally demonstrate a photon-pair source with correlations in the frequency and polarization degrees of freedom. We base our source on the spontaneous four-wave mixing (SFWM) process in a photonic crystal fiber. We show theoretically that the two-photon state is the coherent superposition of up to six distinct SFWM processes, each corresponding to a distinct combination of polarizations for the four waves involved and giving rise to an energy-conserving pair of peaks.

Hawking radiation in optics and beyond.

Hawking radiation was originally proposed in astrophysics, but it has been generalized and extended to other physical systems receiving the name of analogue Hawking radiation. In the last two decades, several attempts have been made to measure it in a laboratory, and one of the most successful systems is in optics. Light interacting in a dielectric material causes an analogue Hawking effect, in fact, its stimulated version has already been detected and the search for the spontaneous signal is currently ongoing.

Boosting few-cycle soliton self-frequency shift using negative prechirp.

Soliton self-frequency shifting of light pulses in fibers is used for versatile tunable light sources. Few-cycle pulses of high soliton number offer unique advantages, in particular the rate of Raman frequency shift is extremely fast. However, their dynamics is complicated, which makes the optimization of the frequency shifting difficult and sometimes counter-intuitive.

Observation of Stimulated Hawking Radiation in an Optical Analogue.

The theory of Hawking radiation can be tested in laboratory analogues of black holes. We use light pulses in nonlinear fiber optics to establish artificial event horizons. Each pulse generates a moving perturbation of the refractive index via the Kerr effect.

Antiplatelet Therapy for Long-Term Management of Patients with Mechanical Aortic Prostheses.

Background: A mechanical aortic prosthesis (MAP) may cause platelet activation secondary to shear forces, and the release of adenosine diphosphate (ADP). This platelet-mediated event may lead to arterial embolism. Traditionally, warfarin has been used to treat such cases, although this anticoagulant has no inhibitory effects on platelets.

Light-emitting diode spherical packages: an equation for the light transmission efficiency.

Virtually all light-emitting diodes (LEDs) are encapsulated with a transparent epoxy or silicone gel. Here we analyze the optical efficiency of spherical encapsulants. We develop a quasi-radiometric equation for the light transmission efficiency, which incorporates some ideas of Monte Carlo ray tracing into the context of radiometry.

Sumoylated RGS-Rz proteins act as scaffolds for Mu-opioid receptors and G-protein complexes in mouse brain.

The RGSZ1 and RGSZ2 proteins, members of the RGS-Rz subfamily of GTPase-activating proteins (GAP), are involved in Mu-opioid receptor desensitization. The expression of these proteins, as well as of their main target the Gz protein, is virtually restricted to the nervous tissue. In synaptosomal membranes, these Rz proteins undergo post-translational modifications such as glycosylation and phosphorylation, and they may covalently attach to small ubiquitin-like modifier (SUMO) proteins.