CC BY
1The 30th International Conference on Advanced Laser Technologies P-O-6
ALT'23
Genetic optimization of the Y-shaped photonic crystal logic element
NOT
Y. Krivosheeva1, D. Golovashkin1'2, V. Pavelyev1'2
1- Samara National Research University, Samara, Russia 2 - IRSIRAS - Branch of the FSRC "Crystallography and Photonics " RAS, Samara, Russia
krivosheeva.yu.yu@gmail.com
Optical logic gates based on photonic crystals have a number of advantages compared to traditional electronics: compactness, high data transfer rate, low power consumption and relatively low manufacturing costs. Therefore, their development seems to be an urgent task. The work [1] presents an interference logic gate AND based on a photonic crystal with a Y-shaped defect. This structure is characterized by manufacturability, efficiency and speed, due to which it can be considered promising.
In addition to the method of using the Y-shaped structure as an AND gate presented by the authors [1], it is proposed to implement the NOT gate on the same photonic crystal. If in a Y-shaped structure [1] signals with a phase difference % are applied to the input ports A and B, then negative interference will be observed in the center of the element and an intensity equal to 0 will be recorded at the output of the element. If, a signal is applied to only one of the ports, for example B, then some part of the signal will go to the output port, which can be interpreted as a logical 1.
Unfortunately, the efficiency (which is understood as the ratio of the intensity at the output port to the intensity at the input) of such an element is not high and amounts to 41.3%. However, optimization methods are known to be applied to photonic crystal structures. Thus, in [2], a genetic algorithm is used to optimize the 90° bend of a photonic-crystal waveguide with a square lattice and silicon rods. The efficiency obtained by the authors was 93%. Here, for the logical gate NOT, a similar approach is applied. In our work, we considered a maximum of 100 generations of the genetic algorithm, 10 individuals each, one individual consisted of eight variable parameters ("chromosomes"), the parents to create a new generation were selected by the roulette wheel method and subjected to single-point crossing, the resulting individuals mutated with a probability of 5%. To find the efficiency of each individual, the direct diffraction problem was solved using the FDTD method [3], which is implemented in the Ansys Lumerical R1 software package. As a result of genetic optimization, the output intensity was 0.949, which is 2.3 times higher than that of the gate without optimization.
The authors of this work suggest further use of the genetic algorithm for the development of logical gates on a photonic crystal basis that implement other logical operations.
[1] Preeti Rani, Yogita Kalra, R.K. Sinha Realization of AND gate in Y shaped photonic crystal waveguide Optics Communications 298-299, 227-231 (2013)
[2] Liyong Jiang, Hong Wu, Wei Jia Optimization of low-loss and wide-band sharp photonic crystal waveguide bends using the genetic algorithm Optik 124(14), 1721-1725 (2013)
[3] Taflove A., Hagness S.C. Computational Electrodynamics: The Finite-Difference Time-Domain Method, Third Edition (Artech House) (2005)
