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

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.

Single Mach-Zehnder interferometer based optical Boolean logic gates.

In this paper, we demonstrate different optical logic gates using a single Mach-Zehnder interferometer with controlled phase modulators in each arm. The operational conditions to obtain 16 optical logic circuits, using the same design, are investigated and are a result of a constructive or destructive interference process. The proposed configuration presents significant low complexity and high scalability, and its feasibility is evaluated through numerical simulations.

Optical reversible programmable Boolean logic unit.

Computing with reversibility is the only way to avoid dissipation of energy associated with bit erase. So, a reversible microprocessor is required for future computing. In this paper, a design of a simple all-optical reversible programmable processor is proposed using a polarizing beam splitter, liquid crystal-phase spatial light modulators, a half-wave plate, and plane mirrors.

Optical programmable Boolean logic unit.

Logic units are the building blocks of many important computational operations likes arithmetic, multiplexer-demultiplexer, radix conversion, parity checker cum generator, etc. Multifunctional logic operation is very much essential in this respect. Here a programmable Boolean logic unit is proposed that can perform 16 Boolean logical operations from a single optical input according to the programming input without changing the circuit design.

All-optical clocked delay flip-flop using a single terahertz optical asymmetric demultiplexer-based switch: a theoretical study.

A flip-flop (FF) is a kind of latch and the simplest form of memory device, which stores various values either temporarily or permanently. Optical FF memories form a fundamental building block for all-optical packet switches in next-generation communication networks. An all-optical clocked delay FF using a single terahertz optical asymmetric demultiplexer-based interferometric switch is proposed and described.

Quaternary Galois field adder based all-optical multivalued logic circuits.

Galois field (GF) algebraic expressions have been found to be promising choices for reversible and quantum implementation of multivalued logic. For the first time to our knowledge, we developed GF(4) adder multivalued (four valued) logic circuits in an all-optical domain. The principle and possibilities of an all-optical GF(4) adder circuit are described.