Photonic Crystals for All-Optical Logic Gates

PHOTONIC CRYSTALS FOR ALL-OPTICAL LOGIC GATES Photonic crystals (PhCs) are periodic dielectric nanostructures that can manipulate light propagation beyond the limitations of standard optics. PhCs can act as "semiconductors of light" by controlling photon transmission through photonic bandgaps. Advantages of PhC-based All-Optical Logic Gates PhC-based all-optical logic gates (AOLGs) have several key advantages:  Can open and engineer photonic bandgaps as needed for different applications  Allow integration of all-optical devices on photonic chips  Overcome limitations of electronic logic gates like power dissipation, input power needs, and delay Proposed Design of Silicon PhC AOLGs The paper presents a design for PhC-based universal AOLGs (NAND, NOR, NOT) using 2D hexagonal lattices of silicon rods in air. The PhC lattice constant and rod radius were optimized to work at 1550 nm. Numerical Modeling and Analysis The structures were modeled and analyzed using the Plane Wave Expansion (PWE) method for dispersion relations and the Finite-Difference Time-Domain (FDTD) method to solve Maxwell's equations rigorously. Results  All 3 logic gates showed good transmission efficiency >80% for logic "1" and <1% for logic "0"  Proposed design is compatible with silicon photonics and can be fabricated using current techniques  Does not require high input power excitation

 Good potential for photonic integrated circuit applications