Design of the Intersection Node of Photonic Crystal Waveguides Using a Genetic Algorithm

Various types of photonic crystal structures intersections are considered: two and three waveguides. In the first case, waveguide propagation occurs without losses, in the second, the intersection node is optimized using a genetic algorithm, which leads to an increase in efficiency by 1.5 times (lossless signal transmission is achieved). Particular attention is paid to the design of the input node and the connections of the planar waveguide with photonic crystal ones. In the first case, the use of a genetic algorithm leads to an increase in efficiency by a factor of 2.3, and the resulting topology of such a node allows radiation to be introduced with virtually no loss. For connections, it is shown that when connecting a planar stepped silicon waveguide with a photonic crystal waveguide with a hexagonal lattice and air holes in a silicon substrate, energy transfer occurs without losses. When replacing a hexagonal lattice with a square lattice, optimization provides an efficiency of more than 99%.