相关论文: Electrically tunable selective reflection of light…
The oblique helicoidal structure is formed in right-angle cholesterics under the applied electric field. The electric field changes the pitch and cone angle but preserves the single-harmonic modulation of the refractive index. As a result,…
Selective reflection of light by oblique helicoidal cholesteric (ChOH) can be tuned in a very broad spectral range by an applied electric field. In this work, we demonstrate that the peak wavelength of the selective reflection can be…
An oblique helicoidal state of a cholesteric liquid crystal (ChOH) is capable of continuous change of the pitch P in response to an applied electric field. Such a structure reflects 50% of the unpolarized light incident along the ChOH axis…
Chiral nematic liquid crystals are one-dimensional photonic band-gap materials whose reflection wavelength can be well tuned by temperature, but only limited and irreversible tuning can be achieved by electric fields. In contrast, oblique…
Peculiarities of the defect modes of cholesteric liquid crystals (CLCs) with an isotropic/anisotropic defect inside are investigated. The influence of the defect layer thickness and its anisotropy of refraction, the influence of the system…
Electrically induced reorientation of liquid crystals (LCs) is a fundamental phenomenon widely used in modern technologies. We observe experimentally an electro-optic effect in a cholesteric LC with a distinct oblique-helicoidal director…
It is known that the oblique helicoidal cholesteric structure (Ch$_{OH}$), which is formed in alternating electrical field applied to the chiral nematic phase (N*) at temperatures above the chiral twist-bend nematic phase (N*$_{tb}$), can…
Heliconical cholesteric liquid crystals are expected to be more sensitive to torque induced by light field since their structure allows both bend and twist in molecular orientations, differently from the conventional cholesterics in which…
Cholesteric liquid crystal elastomers have interesting and potentially very useful photonic properties. In an ideal monodomain configuration of these materials, one finds a Bragg-reflection of light in a narrow wavelength range and a…
We create a one-dimensional photonic crystal with strong polarization dependence and tunable by an applied electric field. We accomplish this in a planar microcavity by embedding a cholesteric liquid crystal (LC), which spontaneously forms…
Colloidal particles dispersed in liquid crystals can form new materials with tunable elastic and electro-optic properties. In a periodic `blue phase' host, particles should template into colloidal crystals with potential uses in photonics,…
Unique electro-optical properties of the oblique helicoidal cholesteric (ChOH) stem from its heliconical director structure. An applied electric field preserves the single harmonic modulation of the director while tuning the ChOH period and…
We study how dispersions of colloidal particles in a cholesteric liquid crystal behave under a time-dependent electric field. By controlling the amplitude and shape of the applied field wave, we show that the system can be reproducibly…
Spherical colloids arranged in a crystalline order are known to produce structural colors. The intensity and brilliance of such photonic crystals require high size-monodispersity of the colloids, a low number of lattice defects and…
Hyperbolic (or indefinite) materials have attracted significant attention due to their unique capabilities for engineering electromagnetic space and controlling light propagation. A current challenge is to find a hyperbolic material with…
We study tunable refraction of light in one-dimensional periodic lattices induced optically in a photorefractive crystal. We observe experimentally both positive and negative refraction of beams which selectively excite the first or second…
Solids with spatially varying photonic structure offer gaps to light of a wider range of frequencies than do simple photonic systems. We solve numerically the field distribution in a solid cholesteric with a linearly varying inverse pitch…
Colloidal systems find important applications ranging from fabrication of photonic crystals to direct probing of phenomena typically encountered in atomic crystals and glasses. New applications - such as nanoantennas, plasmonic sensors, and…
Magneto-optical effects in structured anisotropic media have attracted significant attention due to their potential in tunable photonic devices. In particular, dichroic cholesteric liquid crystals (i.e., cholesterics in which the real parts…
Certain cephalopods can dynamically camouflage by altering both skin texture and color to match their surroundings. Inspired by this capability, we present a cholesteric liquid crystal elastomer-liquid crystal elastomer (CLCE-LCE) bilayer…