Ultra-compact ultra-fast 1-bit comparator based on a two-dimensional nonlinear photonic crystal structure

Abstract

In this paper, a compact optical high-speed 1-bit comparator is proposed based on photonic crystals. In this structure, the nonlinear rods are used at the cross-connecting point of two optical waveguides. The optical transmission and reflection from these rods depend on the amount of the optical intensity. In response to the different states of the input ports, different values of the optical power reach these rods and the interference patterns make the correct function of the output ports. The refractive index and the Kerr coefficient of nonlinear rods are 1.4 m 2 / W and 10 − 14 m 2 / W , respectively. The footprint of the structure is 55 µ m 2 , which is much smaller than the previous works. Besides, the lower delay time is the other advantage of this work compared with the previous works. Based on the simulation results, the proposed structure can be used in integrated optical circuits.

Design and Simulation of Linear All-Optical Comparator Based on Square-Lattice Photonic Crystals

“…In reference [31], the logical value "0" is high, and the structure is also large. Finally, in reference [32], the structure is small, but two outputs are used simultaneously to compare the inputs. The value "1" in this circuit is also weak.…”

“…This circuit compares two bits. Very few studies have been conducted on the design of optical comparators with photonic crystals [27][28][29][30][31][32][33][34].…”

“…In 2020, Seraj et al designed a comparator based on photonic crystals. Despite the small size of this structure, the difference between the high and low logical values is not appropriate [32].…”

Design and Simulation of Linear All-Optical Comparator Based on Square-Lattice Photonic Crystals

“…In reference (Jalali et al 2019), the logical value "0" is high and the structure is also large. Finally, in reference (Seraj et al 2020), the structure is small, but two outputs are used simultaneously to compare the inputs. The value "1" in this circuit is also weak.…”

“…In 2020, Seraj et al designed a comparator based on photonic crystals. Despite the small size of this structure, the distance between the high and low logical values is not long (Seraj et al 2020).…”