A novel proposal for performance improvement in two-dimensional photonic crystal-based 2-to-4 decoders
Mohammad Javad Maleki, Mohammad Soroosh
Abstract
Abstract In this paper, a new photonic crystal-based structure has been proposed for the all-optical 2-to-4 decoder. The structure consists of an array of 19 × 15 chalcogenide rods in the form of the square lattice with a lattice constant of 517 nm. A bias and two input signals are guided through the three waveguides toward the cross-connections to have the constructive interferences. The obtained signal is transmitted through a waveguide that is connected to three nonlinear cavities. To approach the optical Kerr effect, one rod made of a doped-glass with a nonlinear coefficient of 10 −14 m 2 W −1 is placed in each cavity. Based on the amount of the optical intensity, the waves are dropped and guided toward the desired output ports. To obtain the dropping operation at different intensities, the radii of nonlinear rods are adjusted to be 1.13, 1.07, and 1.01 times of ones for the fundamental rods. Unlike the previous works, there is no resonant ring in the proposed structure so the footprint of the device has been reduced to 76 µ m 2 compared to other works. Furthermore, the delay time of the proposed structure is approximately equal to 210 fs which is less than one for all previous works. Besides, the contrast ratio of output ports has been obtained 13.52 dB that is higher than one for other structures. The fast response, small size, and the high contrast ratio of the presented device demonstrate that an improvement in the performance of the photonic crystal-based decoder has been obtained in this work.