The reversible logic gate is a great choice for designing various types of optical processors due to so many advantageous aspects of it; such as low power consumption and the ability of data recovery. At first, the optical circuit of Fredkin gate, a universal reversible logic gate, is designed theoretically using a semiconductor optical amplifier (SOA)-based polarization switch, and the performance of the circuit is studied using simulated results. The frequency-encoded binary data are used to execute the operations. Subsequently, we propose the techniques of developing NOT, AND, OR, EX-OR, EX-NOR gates, and full adder circuit using reversible Fredkin gates. Finally, we develop an optical arithmetic logic unit using the proper combination of reversible Fredkin gates. The theory of nonlinear polarization rotation of the probe beam in the presence of the pump beam in SOA is adopted here. The simulated input–output spectra of the optical circuits enhance the admissibility of the proposed concept.
An optical data processing and communication system provides enormous potential bandwidth and a very high processing speed, and it can fulfill the demands of the present generation. For an optical computing system, several data processing units that work in the optical domain are essential. Memory elements are undoubtedly essential to storing any information. Optical flip-flops can store one bit of optical information. From these flip-flop registers, counters can be developed. Here, the authors proposed an optical master-slave (MS)-JK flip-flop with the help of two-input and three-input optical NAND gates. Optical NAND gates have been developed using semiconductor optical amplifiers (SOAs). The nonlinear polarization switching property of an SOA has been exploited here, and it acts as a polarization switch in the proposed scheme. A frequency encoding technique is adopted for representing data. A specific frequency of an optical signal represents a binary data bit. This technique of data representation is helpful because frequency is the fundamental property of a signal, and it remains unaltered during reflection, refraction, absorption, etc. throughout the data propagation. The simulated results enhance the admissibility of the scheme.