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

Area of Science:

• Optoelectronics
• Digital Systems
• Optical Computing

Background:

• Logic gates are foundational to digital systems, enabling logic and arithmetic operations.
• High-speed communication systems increasingly require all-optical logic and arithmetic capabilities.
• Existing methods may face limitations in speed and synchronization for optical arithmetic.

Purpose of the Study:

• To propose a novel model for all-optical addition and subtraction of two binary digits.
• To design a half-adder and half-subtractor circuit utilizing terahertz optical asymmetric demultiplexer (TOAD) switches.
• To investigate the performance and advantages of the proposed all-optical arithmetic circuit.

Main Methods:

• Development of a theoretical model for optical arithmetic operations.
• Design of a half-adder and half-subtractor circuit using four TOAD-based switches.
• Verification of the circuit design through numerical simulations.

Main Results:

• Successful design of an all-optical half-adder and half-subtractor circuit.
• Demonstration of simultaneous addition and subtraction operations.
• Elimination of input synchronization requirements for optical arithmetic.
• Analysis of performance metrics including extinction ratio, contrast ratio, and Q-factor under varying parameters.

Conclusions:

• The proposed TOAD-based circuit offers a viable approach for high-speed all-optical arithmetic operations.
• The design enhances computational speed and synthesizes light for desired outputs.
• Key parameters influencing switching outcomes were explored through simulations, providing insights for optimization.