Design of all-optical reversible logic gates using photonic crystal waveguides for optical computing and photonic integrated circuits

Reversible logic gates are capable of designing lossless digital systems and which have excessive attention in photonic integrated circuits due to their advantages like, less heat generation and low power dissipation. In this article, all-optical reversible Feynman and Toffoli logic gates are designed for optical computing devices and low power integrated circuits. Proposed designs of all-optical reversible logic gates are implemented with twodimensional (2-D) photonic crystal waveguides without using any nonlinear material. Finitedifference-time-domain method is used to simulate and verify the proposed design and it is operated at a wavelength of 1550 nm. The structure of all-optical reversible logic gates requires very less area and, Feynman logic gate offers the contrast ratio (CR) of 12.4 dB, transmittance 0.96, and less insertion loss of -0.015 dB, Toffoli logic gates offers the CR of 32.5 dB, transmittance 0.9, and less insertion loss of -0.04 dB.