Photonic Crystal Flip-Flops: Recent Developments in All Optical Memory Components

Abstract

This paper reviews recent advancements in all-optical memory components, particularly focusing on various types of all-optical flip-flops (FFs) based on photonic crystal (PC) structures proposed in recent years. PCs, with their unique optical properties and engineered structures, including photonic bandgap control, enhanced light–matter interaction, and compact size, make them especially suitable for optical FFs. The study explores three key materials, silicon, chalcogenide glass, and gallium arsenide, known for their high refractive index contrast, compact size, hybrid integration capability, and easy fabrication processes. Furthermore, these materials exhibit excellent compatibility with different technologies like CMOS and fiber optics, enhancing their versatility in various applications. The structures proposed in the research leverage mechanisms such as waveguides, ring resonators, scattering rods, coupling rods, edge rods, switches, resonant cavities, and multi-mode interference. The paper delves into crucial properties and parameters of all-optical FFs, including response time, contrast ratio, and operating wavelength. Optical FFs possess significant advantages, such as high speed, low power consumption, and potential for integration, making them a promising technology for advancing optical computing and optical memory systems.

Porous-Wall Titania Nanotube Array Layers: Preparation and Photocatalytic Response

“…Because nanoporosity occurs at a spatial length scale far below the wavelength of the guided light, such optimized porous wall TNA layers look as promising candidates for photonic crystals in laser waveguides and demultiplexers [29] and as directional couplers for switching and splitting in Datacom. For such implementation, progress in ensuring pore distribution uniformity and density is required, which will be accomplished by experimenting with a broader range of electrolyte concentrations, voltage pulse amplitude, and frequency.…”

Terahertz Polarization Isolator Using Two-Dimensional Square Lattice Tellurium Rod Array

“…PhCs with photonic band gaps (PBGs) also have been used to design multiple devices for photovoltaic applications [ 13 ] like filters [ 14 ], routers [ 15 ], resonators [ 16 ], optical logic gates [ 17 ], adders [ 18 ], phase shifters [ 19 ] and some all-optical memory components [ 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. The PBGs of some different types of PhCs are generally calculated by the plane wave expansion method (PWEM) based on the Bandsolve module in Rsoftwave, which is a mathematical method used to expand a wave function or physical quantity into a linear combination of plane waves.…”