All-optical logic gates using dielectric-loaded waveguides with quasi-rhombus metasurfaces.

Nanostructure and nanoantenna-based all-optical (AO) devices have attracted significant research interests in recent years due to their small size, high information capacity, ultrafast processing, low power consumption, and overall practicality. Here, in this Letter, we propose a novel metasurface having quasi-rhombus-shaped antennas to modulate optical modes in a dielectric-loaded waveguide for the realization of a complete family of logic gates including NOT, AND, OR, XOR, NAND, NOR, and XNOR. These logic operations are realized using destructive and constructive interferences between the input optical signals. The high contrast ratios of about 33.39, 27.69, and 33.11 dB are achieved for the NAND, NOR, and XNOR logic gates, respectively, with the speed as high as 108 Gb/s.

All-Optical XOR, AND, OR, NOT, NOR, NAND, and XNOR Logic Operations Based on M-Shaped Silicon Waveguides at 1.55 µm.

Silicon waveguides are essential to integrated photonics, which is where optical and electronic components are coupled together on a single silicon chip. These waveguides allow for the integration of signal processing and optical transmission, which advances data centers, telecommunications, and other optical applications. Thus, our study involves the simulation of essential all-optical logic operations, namely XOR, AND, OR, NOT, NOR, NAND, and XNOR, and utilizes M-shaped silicon optical waveguides at a wavelength of 1.55 µm. This simulation is conducted through Lumerical FDTD solutions. The suggested waveguide comprises four identical slots, configured in the shape of the letter 'M', and all of which are formed of core silicon and silica cladding. These logic operations work based on constructive and destructive interferences that are caused by phase changes in the input optical beams. The contrast ratio (CR) is employed to quantitatively and comparatively assess the degree to which the target logic operations are efficiently executed. The simulation results indicate that, compared to other reported designs, the considered logic functions constructed using the proposed waveguide can be implemented with higher CRs. The outcomes of this paper can be utilized regarding the implementation of optoelectronic combinational logic circuits of enhanced functionality.

Optical Logic Gates Based on Z-Shaped Silicon Waveguides at 1.55 µm.

In the last ten years, silicon photonics has made considerable strides in terms of device functionality, performance, and circuit integration for a variety of practical uses, including communication, sensing, and information processing. In this work, we theoretically demonstrate a complete family of all-optical logic gates (AOLGs), including XOR, AND, OR, NOT, NOR, NAND, and XNOR, through finite-difference-time-domain simulations using compact silicon-on-silica optical waveguides that operate at 1.55 µm. Three slots, grouped in the shape of the letter Z, make up the suggested waveguide. The function of the target logic gates is based on constructive and destructive interferences that result from the phase difference experienced by the launched input optical beams. These gates are evaluated against the contrast ratio (CR) by investigating the impact of key operating parameters on this metric. The obtained results indicate that the proposed waveguide can realize AOLGs at a higher speed of 120 Gb/s with better CRs compared to other reported designs. This suggests that AOLGs could be realized in an affordable manner and with improved outcomes to enable the satisfaction of the current and future requirements of lightwave circuits and systems that critically rely on AOLGs as core building elements.

High-Performance All-Optical Logic Operations Using Ψ-Shaped Silicon Waveguides at 1.55 µm.

We simulate with FDTD solutions a complete family of basic Boolean logic operations, which includes XOR, AND, OR, NOT, NOR, NAND, and XNOR, by using compact Ψ-shaped silicon-on-silica optical waveguides that are operated at a 1.55 µm telecommunications wavelength. Four identical slots and one microring resonator, all made of silicon deposited on silica, compose the adopted waveguide. The operating principle of these logic gates is based on the constructive and destructive interferences that result from the phase differences incurred by the launched input optical beams. The performance of these logic operations is evaluated against the contrast ratio (CR) metric. The obtained results suggest that the considered functions designed with the employed waveguide can be realized all-optically with higher CRs and faster speeds than other reported designs.