Time-resolved broadband analysis of slow-light propagation and superluminal transmission of electromagnetic waves in three-dimensional photonic crystals

TL;DR

This study uses time-resolved measurements of THz pulses to analyze slow-light and superluminal effects in 3D photonic crystals, revealing dispersion characteristics and confirming simulation results.

Contribution

It provides the first comprehensive time-resolved broadband analysis of electromagnetic wave propagation in 3D photonic crystals, capturing both slow and superluminal phenomena.

Findings

Evidence of slow group velocities at band edges

Observation of superluminal transmission within the bandgap

Good agreement between experimental data and FDTD simulations

Abstract

A time-resolved analysis of the amplitude and phase of THz pulses propagating through three-dimensional photonic crystals is presented. Single-cycle pulses of THz radiation allow measurements over a wide frequency range, spanning more than an octave below, at and above the bandgap of strongly dispersive photonic crystals. Transmission data provide evidence for slow group velocities at the photonic band edges and for superluminal transmission at frequencies in the gap. Our experimental results are in good agreement with finite-difference-time-domain simulations.