The observation of photon echoes from evanescently coupled rare-earth ions in a planar waveguide

TL;DR

This paper demonstrates the measurement of optical and spin properties of Pr3+ ions in a novel waveguide, showing that their coherence times are comparable to bulk ions, paving the way for integrated quantum systems.

Contribution

It introduces a new waveguide architecture for probing rare-earth ions and confirms their properties are preserved in this integrated platform.

Findings

Inhomogeneous linewidth of 2 GHz measured

Optical coherence time of 70 microseconds achieved

Spin state lifetime of approximately 10 seconds observed

Abstract

We report the measurement of the inhomogeneous linewidth, homogeneous linewidth and spin state lifetime of Pr3+ ions in a novel waveguide architecture. The TeO2 slab waveguide deposited on a bulk Pr3+:Y2SiO5 crystal allows the 3H4 - 1D2 transition of Pr3+ ions to be probed by the optical evanescent field that extends into the substrate. The 2 GHz inhomogeneous linewidth, the optical coherence time of 70 +- 5 us, and the spin state lifetime of 9.8 +- 0.3 s indicate that the properties of ions interacting with the waveguide mode are consistent with those of bulk ions. This result establishes the foundation for large, integrated and high performance rare-earth-ion quantum systems based on a waveguide platform.