Deterministic tuning of slow-light in photonic-crystal waveguides through the C and L bands by atomic layer deposition

TL;DR

This paper presents a method for digitally tuning the slow-light regime in silicon photonic-crystal waveguides using atomic layer deposition of hafnium oxide, enabling precise control without altering dispersion properties.

Contribution

The study introduces a deterministic, passive post-fabrication tuning technique for slow-light in photonic-crystal waveguides via atomic layer deposition, maintaining dispersion characteristics.

Findings

Red-shift of 140 +/- 10 pm per atomic layer

Differential tuning of 110 +/- 30 pm per monolayer between modes

Potential for tuning chip-scale optical interconnects and amplifiers

Abstract

We demonstrate digital tuning of the slow-light regime in silicon photonic-crystal waveguides by performing atomic layer deposition of hafnium oxide. The high group-index regime was deterministically controlled (red-shift of 140 +/- 10 pm per atomic layer) without affecting the group-velocity dispersion and third-order dispersion. Additionally, differential tuning of 110 +/- 30 pm per monolayer of the slow-light TE-like and TM-like modes was observed. This passive post-fabrication process has potential applications including the tuning of chip-scale optical interconnects, as well as Raman and parametric amplification.