Design of all-optical one bit binary comparator using reversible logic gates

In the last few years, reversible logic gates have been used widely for developing various types of arithmetic and logic processors due to its low power consumption and dissipation. Researchers prefer reversible logic gates for designing several types of optical switching devices in all-optical communication network. The modern high speed network, based on the conventional irreversible logic gates, faces a serious problem of heat generation due to the bit loss at the output, and the basic reason behind it is the unequal number of inputs and outputs. In case of reversible logic gate, the inputs are directly mapped to the outputs and thus, there is no chance of bit loss. Consequently, generation of heat due to bit loss is not possible ideally. In this article, authors have proposed a new technique for developing all-optical Feynman gate which is a simple two-input two-output reversible logic gate. All-optical circuit has been designed using optical polarization switches (PSW), made of Semiconductor Optical Amplifiers (SOA). The working principle is based on the theory of nonlinear polarization rotation of the probe beam in the SOA. Authors have also designed all-optical one bit binary comparator using reversible logic gates. The proposed scheme works on frequency encoded data. As the frequency is the inherent property of the signal, frequency encoded data based logic gates are more preferable for designing arithmetic and logic processor. Simulated results enhance the admissibility of the proposed schemes.