An alternative approach to design half-subtractor using reflective semiconductor optical amplifier with numerical simulation

In this communication, we have proposed an alternative approach to design the half subtractor which is based on reflective semiconductor optical amplifiers (RSOAs) and dibit-based logic. RSOA shows higher gain than conventional SOA at low bias current. To enrich security, we have introduced dibit-based logic to encode the signal. Here, logic state ‘1’ represents the presence of soliton pulse and logic state ‘0’ represents no pulse. The simulation is performed in MATLAB software and we have investigated the values of quality factor (Q), extintion ratio, contrast ratio etc. using numerical simulation. The simulated output Q-values of 1st and 2nd bits for difference and borrow are 36.74, 26.32 and 42.80, 24.37 dB respectively. The simulated output CR values of 1st and 2nd bits for difference and borrow are 47.41, 41.70 and 52.56, 40.03 dB respectively. We have also studied the relative eye opening (REOP) with the amplified stimulated emission noise and with out this noise and with noise the signal’s eye-opening changes \(<1\%\) $<1\%$ .