No Arabic abstract
Recently, two special photonic jets, photonic hooks and twin photonic jets, have been proposed to deal with complex conditions in nanoscale manipulation. Photonic hooks are generated by a single light plane wave and an asymmetric microparticle, while the twin photonic jets are produced by two incident light beams. In this letter, we presented and demonstrate a method to combine photonic hooks and twin photonic jets. A single light plane wave and a symmetric microparticle, twin-ellipse microcylinder, are used in this research. The curvature degree, length and maximum E2 filed enhancement of twin photonic hooks are varied significantly, with the change of refractive indices and shape of twin-ellipse microcylinder. And a liquid-immersed core-shell is built to achieve a flexible tunability.
The photonic hook, a beam that can propagate along a curved path, has attracted wide attention since its inception and experimental confirmation. In this paper, we propose a new type of structure, which was made by a hollow microcylinder and a Janus-shaped liquid column of two insoluble filling liquids, for producing photonic hook of easily tunable properties and long length. The E^2 field intensity distribution characteristics and formation mechanism of the photonic hook are studied by analyzing the energy flow using the finite element method. The profile and properties of the photonic hook can be effectively tuned by rotating the hollow microcylinder or changing the light incident angle. A long photonic hook with a decay length of ~18{lambda} and a photonic hook with a large focal distance ~8{lambda} are obtained by this model.
It is well-known that electromagnetic radiation propagates along a straight line, but this common sense was broken by the artificial curved light - Airy beam. In this paper, we demonstrate a new type of curved light beam besides Airy beam, so called photonic hook. This photonic hook is a curved high-intensity focus by a dielectric trapezoid particle illuminated by a plane wave. The difference of the phase velocity and the interference of the waves inside the particle cause the phenomenon of focus bending.
During the last 2 years, it was shown that an electromagnetic beam configuration can be bent after propagation through an asymmetrically shaped (Janus) dielectric particle, which adds a new degree of simplicity for generation of a curved light beam. This effect is termed photonic hook (PH) and differs from Airy-family beams. PH features the smallest curvature radius of electromagnetic waves ever reported which is about 2 times smaller than the wavelength of the electromagnetic wave. The nature of a photonic hook is a the dispersion of the phase velocity of the waves inside a trapezoid or composed particle, resulting in an interference afterwards.
We optimize multilayered anti-reflective coatings for photovoltaic devices, using modern evolutionary algorithms. We apply a rigorous methodology to show that a given structure, which is particularly regular, emerge spontaneously in a very systematical way for a very broad range of conditions. The very regularity of the structure allows for a thorough physical analysis of how the designs operate. This allows to understand that the central part is a photonic crystal utilized as a buffer for light, and that the external layers have the purpose of reducing the impedance mismatch between the outer media and the Bloch mode supported by the photonic crystal. This shows how optimization can suggest new design rules and be considered as a source of inspiration. Finally, we fabricate these structures with easily deployable techniques.
We present the use of linearly down-tapered gas-filled hollow-core photonic crystal fiber in a single-stage, pumped with pulses from a compact infrared laser source, to generate a supercontinuum carrying significant spectral power in the deep ultraviolet (200 - 300 nm). The generated supercontinuum extends from the near infrared down to around 213 nm with up to 0.83 mW/nm in the deep ultraviolet.