Abstract- All-optical half-adder/half-subtractor using terahertz optical asymmetric demultiplexer

All-optical half-adder/half-subtractor using terahertz optical asymmetric demultiplexer Dilip Kumar Gayen, Tanay Chattopadhyay, Arunava Bhattacharyya, Saikat Basak, and Dipanti Dey  »View Author Affiliations

Applied Optics, Vol. 53, Issue 36, pp. 8400-8409 (2014)
http://dx.doi.org/10.1364/AO.53.008400

http://www.opticsinfobase.org/ao/abstract.cfm?uri=ao-53-36-8400

Logic gates are the fundamental building blocks of digital systems. Using these logic gates, one can perform different logic and arithmetic operations. All-optical logic and arithmetic operations are very much expected in high-speed communication systems. In this paper, we present a model to perform addition/subtraction operations on two binary digits based on a terahertz optical asymmetric demultiplexer (TOAD). Using four TOAD-based switches, we have designed a half-adder and half-subtractor circuit. The approach to designing all-optical arithmetic circuits not only enhances the computational speed but is also capable of synthesizing light as inputs to produce the desired outputs. The main advantages of this circuit are that synchronization between inputs is eliminated and simultaneous addition and subtraction operations are realized at the outputs. This circuit is designed theoretically and verified through numerical simulations. The impact of the control pulse energy, gain recovery time, and the input data pulse width on the extinction ratio, contrast ratio, amplitude modulation, Q-factor, and relative opening of the pseudo-eye diagram of the switching outcome is explored and assessed by means of numerical simulations.

© 2014 Optical Society of America