Pulse propagation through a slab with time-periodic dielectric function ε(t).

Area of Science:

• Optics and Photonics
• Condensed Matter Physics
• Electromagnetism

Background:

• Extends previous work on monochromatic wave propagation in time-varying dielectric media.
• Builds upon established concepts of phase and group delays in wave propagation.

Purpose of the Study:

• To analyze the propagation of quasi-monochromatic pulses through a slab with a time-dependent dielectric function.
• To investigate the characteristics and velocities of transmitted partial pulses.

Main Methods:

• Theoretical analysis using phase and group delay concepts.
• Numerical simulations to study pulse propagation and velocities.
• Extension of prior monochromatic wave analysis to pulsed incidence.

Main Results:

• Transmitted pulse is a superposition of replicas with harmonic carrier frequencies.
• Partial pulses exhibit diverse velocities, including superluminal (v > c) and slow light (v << c).
• Peak pulse velocity and partial pulse velocities do not diverge, unlike bulk group velocity.

Conclusions:

• The study provides a theoretical framework for understanding pulse propagation in dynamic periodic media.
• Numerical results reveal complex pulse behavior, including superluminal and slow-light phenomena.
• Findings have potential experimental verification in the microwave regime.