Slow light transmission in one-dimensional periodic structures

TL;DR

This paper investigates how to optimize slow light transmission in one-dimensional periodic structures, focusing on maximizing delay while minimizing pulse distortion, with implications for telecommunications.

Contribution

The study provides a systematic analysis of pulse transmission conditions in 1D periodic structures, highlighting the role of Lorentzian resonances and the ratio of resonance width to separation.

Findings

Transmission can be approximated by Lorentzian resonances.

High index contrasts lead to significant pulse distortion.

Achievable fractional delays depend on pulse bandwidth and frequency.

Abstract

We have analyzed the transmission properties of pulses through one-dimensional periodic structures in order to systematically explore the best conditions to achieve the maximum delay with the minimum possible distortion. In the absence of absorption and no layer variation, the transmission coefficient $t_N$ can be well approximated by a sum of Lorentzian resonances. The ratio between their width $\Gamma_{\rm r}$ and their separation $\Delta\omega_{\rm r}$ is a crucial parameter to characterize the distortion of the transmitted pulse. For typical values of the parameters used in telecommunications and high index of refraction contrasts $n_2 / n_1$, the distortion of the transmitted pulse is unacceptably large for frequencies near the edge of the transmission window. We estimate fractional delays achievables in terms of the central frequency used and the pulse bandwidth.