Imaging stretching and displacement using gradient-index elements during the lens design process.

In this study, we propose an approach to stretch or translate images using gradient-index (GRIN) elements with a rotationally symmetric shape in lens systems. In this method, the GRIN material, instead of optical surfaces, are utilized to enable a breaking of rotational symmetry for the two image translations. GRIN expression with anamorphic and tilting terms is introduced.

Christiansen filters realized with cylindrical lenses of even symmetry.

A type of Christiansen filter that takes the form of a smooth cylindrical lens of even symmetry is proposed. By varying the shape of the lens, the filter can be made to realize many common filtering responses, including the polynomial function response, the Gaussian function response, and the sinc function response. A systematic design technique based on inverse scattering is established, and a desired, prescribed response can be tailored by properly shaping the lens of the filter.

Experimental observation of wave localization at the Dirac frequency in a two-dimensional photonic crystal microcavity.

Trapping light within cavities or waveguides in photonic crystals is an effective technology in modern integrated optics. Traditionally, cavities rely on total internal reflection or a photonic bandgap to achieve field confinement. Recent investigations have examined new localized modes that occur at a Dirac frequency that is beyond any complete photonic bandgap.

Spatial algebraic solitons at the Dirac point in optically induced nonlinear photonic lattices.

The discovery of a new type of soliton occurring in periodic systems is reported. This type of nonlinear excitation exists at a Dirac point of a photonic band structure, and features an oscillating tail that damps algebraically. Solitons in periodic systems are localized states traditionally supported by photonic bandgaps.

Modulation of large absolute photonic bandgaps in two-dimensional plasma photonic crystal containing anisotropic material.

The large absolute photonic bandgaps of two-dimensional (2D) anisotropic magnetic plasma photonic crystals with hexagonal and square lattices are obtained by introducing tellurium dielectric rods using the modified plane wave expansion method. Equations for calculating the band structures in the irreducible part of the first Brillouin zone are theoretically deduced. The modulation properties indicate that the location and bandwidth of the absolute photonic bandgaps (PBGs) could be tuned by filling factor, plasma frequency, and magnetic field.

Light trapping at Dirac point in 2D triangular Archimedean-like lattice photonic crystal.

Optical cavities and waveguides are critical parts of modern optical devices. Traditionally, optical cavities and waveguides rely on photonic bandgaps, or total internal reflection, to achieve light trapping. It has been reported that a novel light trapping, which exists in triangular and honeycomb lattices, is attributed to the so-called Dirac point.

Chemical composition and antibacterial activity of the essential oil from Agathis dammara (Lamb.) Rich fresh leaves.

The essential oil of fresh leaves from Agathis dammara (Lamb.) Rich was extracted using hydro-distillation, and GC-FID and GC-MS were used to analyse the essential oil. Nineteen compounds were identified, among which the major components were limonene (36.

Polarization splitter based on dual-core photonic crystal fiber.

A polarization splitter based on a new type of dual-core photonic crystal fiber (DC-PCF) is proposed. The effects of geometrical parameters of the DC-PCF on performances of the polarization splitter are investigated by finite element method (FEM). The numerical results demonstrate that the polarization splitter possesses ultra-short length of 119.

A chiral mixed metal-organic framework based on a Ni(saldpen) metalloligand: synthesis, characterization and catalytic performances.

A three-dimensional (3D) chiral mixed metal-organic framework [Cd4Cl(Ni-L)3(Ni-HL)(H2O)6(DMF)]·4DMF (CMOF 1) based on a new enantiopure dicarboxyl-functionalized Ni(saldpen) metalloligand Ni-H2L and a novel tetranuclear cadmium cluster [Cd4Cl(CO2)7(CO2H)] has been synthesized and characterized by elemental analyses, IR and UV-vis spectra, thermogravimetric analysis, nitrogen and carbon dioxide adsorption, powder and single-crystal X-ray diffractions. Each tetranuclear-cadmium cluster in 1 is linked by eight Ni-L ligands, and each Ni-L ligand is linked by two tetranuclear-cadmium clusters to generate a 3D framework with 1D open channels (∼1.1 × 0.