Tip-induced nanoscale domain engineering in x-cut lithium niobate on insulator.

Nanodomain engineering in lithium niobate on insulator (LNOI) is critical to realize advanced photonic circuits. Here, we investigate the tip-induced nanodomain formation in x-cut LNOI. The effective electric field exhibits a mirror symmetry, which can be divided into preceding and sequential halves according to the tip movement.

Progress of Angiogenesis Signal Pathway and Antiangiogenic Drugs in Nasopharyngeal Carcinoma.

Nasopharyngeal cancer is a rare cancer with unique ethnic and geographic distribution. Since nasopharyngeal cancer often originates from the pharyngeal crypt, early symptoms are not obvious. They are difficult to detect in time, and the disease is usually diagnosed and treated only when it has progressed to an advanced-stage.

Efficient nonlinear beam shaping in three-dimensional lithium niobate nonlinear photonic crystals.

Nonlinear beam shaping refers to spatial reconfiguration of a light beam at a new frequency, which can be achieved by using nonlinear photonic crystals (NPCs). Direct nonlinear beam shaping has been achieved to convert second-harmonic waves into focusing spots, vortex beams, and diffraction-free beams. However, previous nonlinear beam shaping configurations in one-dimensional and two-dimensional (2D) NPCs generally suffer from low efficiency because of unfulfilled phase-matching condition.

Broadband Variable Meta-Axicons Based on Nano-Aperture Arrays in a Metallic Film.

Metasurfaces are two-dimensional metamaterials composed of a carefully designed series of subwavelength meta-atom (antenna or aperture) arrays. These surfaces can manipulate the phase, amplitude and polarization of output light by changing the shapes and orientations of the meta-atoms on a subwavelength scale. Using these properties, we experimentally demonstrate variable meta-axicons composed of rectangular nano-apertures arranged in several concentric rings that can focus left circularly polarized (LCP) light into a real Bessel beam and defocus right circular polarized (RCP) light to form a virtual beam.

Survival of the orbital angular momentum of light through an extraordinary optical transmission process in the paraxial approximation.

We report on the extraordinary optical transmission (EOT) of an orbital angular momentum (OAM) state of light in the paraxial approximation. The OAM state transmits through a subwavelength metal hole array with a square structure, and then is analyzed by using a Mach-Zehnder interferometer. In the experiment, the transmitted light well conserves the OAM information while the transmission efficiency of the OAM mode is much greater than 1 (i.

[GaN-based white-light-emitting diodes with low color temperature and high color rendering index].

The luminescence properties of high color rendering white LED depending on the proportions of mixed phosphor powders were investigated by adopting green and red phosphors stimulated by a 440 nm InGaN/GaN based blue LED. The results show that when the proportion of A/B type silica gels and green/red phosphor powders is 0.5 : 0.