All-optical switching in a symmetric three-waveguide coupler with phase-mismatched absorptive central waveguide

Area of Science:

• Photonics and optical engineering
• Nonlinear optics
• Integrated optics

Background:

• All-optical switching is crucial for high-speed optical communication networks.
• Previous two-waveguide coupler designs faced fabrication and index matching challenges.
• Controlling light-by-light interaction is key for advanced photonic devices.

Purpose of the Study:

• To theoretically investigate an all-optical switching operation in a novel three-waveguide directional coupler.
• To demonstrate a switching mechanism based on manipulating absorption in the central waveguide.
• To overcome fabrication and index-matching limitations of prior optical switch architectures.

Main Methods:

• Theoretical analysis of light propagation in a three-waveguide directional coupler.
• Modeling optically induced absorption changes in the central waveguide.
• Simulating the control of light coupling between passive side waveguides.

Main Results:

• The proposed three-waveguide structure enables all-optical switching by modulating absorption.
• Optically induced absorption effectively controls inter-waveguide light coupling.
• The architecture accommodates large modal index differences without sacrificing switching performance.

Conclusions:

• The developed three-waveguide coupler offers a promising platform for efficient all-optical switching.
• This design provides a more robust and feasible alternative to existing two-waveguide schemes.
• Further research could explore practical implementation and performance optimization.