Slow Light in a Bragg Waveguide

TL;DR

This paper investigates slow light in Bragg waveguides, demonstrating high group indices and manageable pulse distortion, with potential for even higher indices when incorporating quantum wells, marking a novel analysis in this field.

Contribution

It provides the first analysis of pulse propagation related to slow light in Bragg waveguides, including effects of quantum wells for enhanced slow light.

Findings

Group index of ~1000 in TiO₂/SiO₂ waveguides

Spatial decay length of ~3 mm for nanosecond pulses

Potential to reach group index of ~10000 with quantum wells

Abstract

One-dimensional defect photonic crystal (Bragg waveguide) is studied from the viewpoint of the slow light problem. The calculations are presented showing that in the TiO$_2$/SiO$_2$-based Bragg waveguide one can obtain the group index of $\sim$ 1000 and spatial decay length of $\sim$ 3 mm for a nanosecond-scale pulse. Distortion of the pulse due to the group index dispersion proves to be acceptable for the relative pulse delay not exceeding 10. We also analyze propagation of the light pulse in the Bragg waveguide with a quantum well inside and provide arguments showing possibility of reaching the group index of $\sim$ 10000. To the best of our knowledge, analysis of pulse propagation in a Bragg waveguide in connection with the slow light problem has not been performed so far. We will still much appreciate any information about such studies, if any.