All-Optical Two-Bit Magnitude Comparator Using Quantum-Dot Semiconductor Optical Amplifier

We construct three types of a two-bit magnitude all-optical digital comparator by cascading logic gates using quantum-dot semiconductor optical amplifiers (QD-SOAs). By conducting numerical simulations, we investigate and evaluate the performance of the devices implemented by different configurations. Based on these results, we specify the pros and cons of the each configuration in terms of the number of logic gates and QD-SOAs, values of extinction ratio, and peak power of the final output.