Abstract An all optical encoder based triangular lattice shape photonic crystal (PC) is proposed. The device composed of two ring resonator waveguides and OR gate with four input ports output in PC. band diagram base PC structure calculated by plane wave expansion (PWE) method. Also, transmission distribution electrical field behaviors the proposed are verified dimensional finite difference time domain (2D-FDTD) 4 × 2 can operate at third communication window range, considering definitions...

Abstract This study investigates the temperature-dependent behaviors of three novel high-birefringence (Δ n ) nematic liquid crystals (NLCs) with varying clearing temperatures ( T NI ). The high birefringence studied is advantageous for LCD applications. It ensures fast response times, wide viewing angles, enhanced color reproduction, and reduced cross-talk, optimizing display performance image quality. goal to characterize their order parameters S(T) ), effective geometry α eg normalized...

Abstract The most recently developed optical encoders are based on non-linear Kerr effect which require high input power. Here, we report 8 to 3 binary encoder linear effects greatly reduces the power requirement. proposed consists of three 4-input port OR gates and an buffer gate. Simulation results have proved correct operation states numerical analysis is done in order additional evaluation. maximum switching delay total footprint structure about 160 fs 1418 µm 2 , respectively.

We consider the behavior of optical bistability (OB) and multistability (OM) in a four-level atomic system involving Rydberg state illuminated by probe field as well control switching laser beams larger intensity. When is absent, no OB arises because effect electromagnetically induced transparency. However, application field, hysteresis cycle appears to give rise bistability, thanks absorption. It further demonstrated that one can efficiently modify threshold via suitable choices...

A new tolane-base liquid crystal, 4'-heptyl-3-fluoro-4-isothiocyanatotolane (7TOLF), and a biphenyl-base nematogen, 4'-heptyl-3-fluoro-4-isothiocyanatobiphenyl (7BF), have been investigated for the first time to determine their electro-optical behaviour third order non-linearity using static Kerr effect method. Both nematic compounds fluorine atom attached phenyl-NCS moiety. They possess same polar head group (-NCS) alkyl tail (-C7H15). So of tolane nematogen on was compared. The temperature...

In this paper, we investigate the generation and controlling of optical vortex beam using a dye-doped liquid crystal (DDLC) cell. The spatial distribution quasi-sinusoidal orientation molecules creates phase grating (PG) in DDLC Depending on incident light pattern, Trans to Cis photoisomerization dye affects molecules. To do so, an amplitude fork (FG) is used as mask, its pattern stored cell by printing method PG. One particular features capability diffraction efficiency controlled applied...

A new type of wideband slow light with a large delay bandwidth product in slab photonic crystal waveguide triangular lattice circular air holes silicon-on-insulator substrate based on optofluidic infiltration is demonstrated. It shown that dispersion engineering through infiltrating optical fluids-with different refractive indices n(1f) and n(2f)--in the first two rows innermost to results an improved normalized ranging from 0.187 0.377 (12 nm<Δλ<32 nm) group index (14.20< n(g)< 24.62)...

In this work the dynamic of formation permanent holographic grating have been investigated. Also effect cell thickness and intensity writing beams on permanency in Azo Dye Doped Liquid Crystals (ADDLC) is studied. Homogeneously aligned pure 1294-1b liquid crystal doped with Methyl Red (with 1% wt) are used to achieve purpose. The results compared literatures, showing optimized properties for constructing an optical memory high diffraction efficiency long duration.

Abstract Static Kerr effect and the pre-transition temperature were investigated for 6CHBT, 6BOBT nematic mixtures, M1 (40% 6CHBT: 60% 6BOBT), M2 (30% 70% 6BOBT) M3 (20% 80% at temperatures above nematic-isotropic transition temperature. The linear dependence of (T-T*)−1 on constant is found to be in good agreement with predications Landau-De Gennes model. hypothetical second order phase susceptibility values determined these compounds.

Sharp metal edges (like wedge or triangular geometries) have been widely studied as low-loss surface plasmon polariton (SPP) waveguiding structures. However, fabrication difficulties lead to round-shaped tips which larger mode size and shorter propagation length. As a solution, here we present an easy realize structure for turning edge-less bump metallic geometry (whose is less troublesome) into hybrid one. Through investigating the geometrical dispersion, lengths of up half millimetre...

The formation of refractive index grating in pure and doped Nematic Liquid Crystal (pure 5CB with SBB) planar cells has been investigated. A DC voltage is applied to the samples a He-Ne laser used as writing beam form grating. It observed that doping LC azo dye leads higher diffraction efficiency respect one lower needed intensities. These observations are described by orientation liquid crystal molecules, which can only be detected P-polarized probe beam.

In this experimental work, we investigated the dynamic behaviour of transient holographic grating in an Azo dye doped nematic liquid crystal, formed by a pulsed laser. Relaxation was studied two geometries, when director is parallel or perpendicular to vector. time constants for different writing angles were used measure diffusion coefficients. The obtained results show anisotropic photo excited molecules.

Electro-optical Kerr effect data have been obtained for 6CB, 6CHBT, 6PCH, and 6BOBT at temperatures greater than the nematic–isotropic transition temperature. Using these data, real parts of third-order nonlinear susceptibility χ(3) are determined all liquid crystals. All compounds had a positive constant, which increased with decreasing The second-order phase-transition temperatures, T*, were compounds. replacement aromatic ring by flexible cyclohexyl group or bulkier bicyclooctane has...