All-optical logic NOR gate using a single quantum-dot SOA-assisted an optical filter

Abstract

We thoroughly explore the characteristics of an ultrafast all-optical NOR gate for 160 Gb/s return-to-zero Gaussian data signals using a single quantum-dot semiconductor optical amplifier (QD-SOA) and an optical filter (OF). In this proposed scheme, we employ an optical clock signal as a probe in addition to data signals as pumps between which the Boolean NOR function is executed. By conducting numerical simulations, we investigate and evaluate the effects of various critical factors on the extinction ratio and Q2-factor. This enables us to specify the margins of clock wavelength, peak power of data and clock signals, current density, electron relaxation time from the excited state to the ground state, linewidth enhancement factor, small signal gain of QD-SOA, OF bandwidth and order, the permissible extent of arrival time difference between data signals and clock, and the effect of amplified spontaneous emission. Moreover, we demonstrate that the proposed device can be applied to a multiple-input NOR gate. The results show that the proposed NOR gate can be achieved with both logical correctness and high quality when the specified conditions are satisfied.