Tunneling escape in optical waveguide arrays with a boundary defect

Area of Science:

• Physics
• Optics
• Condensed Matter Physics

Background:

• Coupled optical waveguides are fundamental for light manipulation.
• Understanding light propagation and decay is crucial for photonic devices.
• Defects in periodic structures can significantly alter wave behavior.

Purpose of the Study:

• To theoretically demonstrate the tuning of light decay laws in tunneling-coupled optical waveguides.
• To analyze the impact of a boundary defect on light propagation dynamics.
• To explore different decay regimes achievable through defect engineering.

Main Methods:

• Development of a theoretical model for light propagation in a semi-infinite array of coupled waveguides.
• Derivation of an analytical solution for the decay law using a Neumann series expansion.
• Investigation of parameter space to identify distinct decay regimes.

Main Results:

• An analytical form for the light decay law was obtained for a semi-infinite array with a boundary defect.
• Demonstration of tunable decay regimes, including near-exponential, oscillatory power-law, and nonoscillatory power-law.
• Identification of parameter ranges where the boundary defect does not support localized modes, leading to diverse decay behaviors.

Conclusions:

• The decay law of light in coupled optical waveguides can be effectively tuned by introducing a boundary defect.
• The presence of a defect without localized modes offers a pathway to achieve various decay characteristics.
• This theoretical work provides insights into controlling light dynamics in engineered optical systems.