Design of optical logic gates using self-collimated beams in 2D photonic crystal

Abstract

Optical logic gates are elementary components for optical network and optical computing. In this paper, we propose a structure for AND, NAND, XNOR and NOR logic gates in the two dimensional photonic crystal which utilizes the dispersion based self-collimation effect. The self-collimated beam is splitted by the line defect and interfered with other self-collimated beam. This interference may be constructive or destructive based on their phase difference. This phenomenon is employed to realize all-optical logic gates. The gates are demonstrated numerically by computing electromagnetic field distribution using the finite difference time domain (FDTD) method. The results ensure that this design can function as AND, NAND, XNOR and NOR logic gates. The size of the structure is about 10 μm×10 μm which in turn results in an increase in the speed and all the gates are realized in the same configuration. The ON-OFF contrast ratio is about 6 dB.

Modeling of all-optical even and odd parity generator circuits using metal-insulator-metal plasmonic waveguides

“…Some switching circuits were also proposed by using semiconductor optical amplifier (SOA) but they were backsitted due to the phenomenon of gain saturation [21]. All optical logic gates were also proposed using photonic crystal but being lack of the nonlinear material inside the structure will enable the switching of optical signals for complex circuits [22].…”

Realization of all optical half-adder based on self-collimated beams by two-dimensional photonic crystals

“…Recently, great efforts have been made on the logic gate design through different ways such as self-collimation effect [16,17], multi-interference [18,19] and nonlinear photonic crystal ring resonator [20,21]. Different types of logic gates can be accomplished in one configuration [18] and one logic gate can operate on different wavelengths [22].…”

“…Presently, great efforts have been made on the all optical half adder and it was realized through cross structures [23] or nonlinear effects [24] in 2D PCs. Although the AND, NAND, XNOR, and NOR logic gate based on self collimated effect was realized in the report [16], the all optical half adder based on self-collimated effect has not yet been researched. In this paper, a novel all optical half adder design based on the self collimated effect in 2D PCs is proposed and realized by the line defect in the 2D PCs.…”

An approach to achieve all-angle, polarization-insensitive and broad-band self-collimation in 2D square-lattice photonic crystals

“…The SC can benefit a large variety of applications related to wave guiding and light collection, e.g. waveguides for optical integrated circuits [21,22], beam splitters [23,24], optical switches [25], multiplexers [26], sensors [27], interferometers [28], wave plates [29], resonators [30,31], and logic gates [32,33]. The SC allows a narrow beam to propagate in the PC without engineered defects or physical channel and hence it may simplify fabrication of some PC-based devices.…”