Ultra-high-speed all-optical half subtractor for optical signal processing

All-optical half subtractor (AHS) is the very essential circuit to perform very-high speed operations in the present electronic world. The paper focuses on implementation of AHS by using photonic crystal (PhC) T-shaped waveguides. This structure works on beam interference pattern, and the output results are simulated using finite-difference time-domain method (FDTD). The suggested structure is of compact size of 27.72 μm 2 and good contrast ratio (CR) of 15.79 for difference (Diff) and 11.22 for borrow (Borr) with the bit rate of 90.9 Tbps that can bring out in optical signal processing.