Mach-Zehnder Interferometer Based All Optical Reversible Carry-Lookahead Adder

In this work, we present an efficient reversible implementation of Carry-Lookahead Adder (CLA) in all-optical domain. Now-a-days, semiconductor optical amplifier (SOA)-based Mach-Zehnder interferometer (MZI) plays a vital role in the field of ultra-fast all-optical signal processing. We have used all optical based Mach-Zehnder Interferometer (MZI) switches to design the CLA circuit implementing reversible functionality. Two approaches are proposed for designing the CLA circuit. First, we propose a hierarchical approach for implementation of 2n-bit reversible CLA. In the second approach, we remove the drawback of hierarchical CLA and improve the design by implementing non-modular staircase structure of n-bit reversible CLA. The design complexities of both the approaches are computed. Experimental result shows that the optical cost and delay incurred in staircase structured reversible implementation of CLA are much less than those proposed in the recently reported works.