Implementation of optical OR and NOR gates using Mach-Zehnder interferometers

The ever increasing growth of data and the need for data transmission emphasizes the requirement of full-optical telecommunication. Therefore, it seems critical to utilize optical integrated circuits, including optical gates, optical dividers, optical converters, etc. In this regard, we introduce a new structure for OR/NOR logical gate. The OR/NOR logical gate is simulated by applying Mach–Zehnder interferometer (MZI) where switching between bar and cross states is implemented by using the electro-optic properties of Lithium Niobate and coupling mode theory. Two different designs for the OR/NOR basic gate are simulated by OptiBPM software. Simulation results show that designed gates implement OR/NOR logical gate completely acceptable. The advantage of these designed gates is that waveguides have smaller length and do not pass above each other; thereby it would be possible to do layering by using fewer layers. Also, results show that output intensity in '1' logic state is more than 95% of input light and in '0' logic state, is less than 5% of the input light. (paper)