Designing of Optimized All-Optical Half Adder Circuit Using Single Quantum-Dot Semiconductor Optical Amplifier Assisted Mach-Zehnder Interferometer

A new and novel scheme for a high speed all-optical half adder based on single Quantum-dot semiconductor optical amplifier (QD-SOA) assisted Mach-Zehnder interferometer (MZI) is theoretically investigated and discussed. In this proposed scheme, pair of input data streams are simultaneously drive the switch to produce sum and carry. In this new design, only single switch can be utilized to design half adder circuit and no additional input beam is required other than two input signals. This design is simpler, smaller and compact than our previously proposed design . The impact of the peak data power as well as of the QD-SOAs current density and maximum modal gain on the ER, Q factor with current densities and electron relaxation times etc are explored and assessed by means of numerical simulations.