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

Abstract

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.

Silicon-on-silica waveguides-based all-optical logic gates at 1.55 μm

“…and '0' based on simple and less expensive waveguides. Additionally, the proposed design operates at a higher rate of 120 Gb s −1 and achieves higher CRs than reported in previous designs [6,7,[11][12][13]. This helps meet the growing demands and future needs for optical logic and processing at faster speeds and with better performance.…”

All-optical logic operations based on silicon-on-insulator waveguides

“…The FDTD intensity monitors are used for recording the light intensities at the input and output ports. The spectral transmission (T) is defined as T ¼ I out ∕I in ¼ jE out j 2 ∕jE in j 2 , 14,19 where I out is the intensity at the output port (i.e., P out ), and…”

“…The FDTD intensity monitors are used for recording the light intensities at the input and output ports. The spectral transmission (T) is defined as T=Iout/Iin=|Eout|2/|Ein|2, 14 , 19 where Iout is the intensity at the output port (i.e., Pout), and Iin=I1+I2+I3 is the sum of the intensities at the three input ports. The threshold transmission (Tth) of 0.2 is first set to decide the desired logic function.…”

“…On the other hand, the development of all-optical (AO) logic technologies is fundamental to realize future telecommunication networks with the exponential growth of internet traffic. Several waveguides, including photonic crystal waveguides, 2 – 9 semiconductor platforms, 10 – 14 gold nanowire waveguides, 15 metal slot waveguides, 16 metal–insulator–metal structures, 17 dielectric–metal–dielectric design, 18 dielectric–loaded waveguides, 19 graphene–containing compact microdisks, 20 and optical amplifiers, 21 have been used to create AO logic gates in recent years. The majority of these published designs only used photonic crystals to realize one or, at most, two logic gates, 2 – 13 in contrast to the suggested waveguide, which simultaneously realized seven logic operations.…”

“…The majority of these published designs only used photonic crystals to realize one or, at most, two logic gates, 2 – 13 in contrast to the suggested waveguide, which simultaneously realized seven logic operations. Furthermore, some of these reported projects have utilized more expensive noble metals, such as gold and silver, 15 – 19 as compared to the materials (i.e., silicon and silica) used in our design. Therefore, implementing multifunctional logic gates with high contrast ratios (CRs) between the output logic states “1” and “0” based on basic and inexpensive waveguides remains a significant challenge.…”