title: Observation of Photon Echoes From Evanescently Coupled Rare-Earth Ions in a Planar Waveguide.
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  μs, 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.
authors.affiliation: Laser Physics Centre, Australian National University, Canberra, Australian Capital Territory 2601, Australia.|Centre for Quantum Computation and Communication Technology, Laser Physics Centre, Australian National University, Canberra, Australian Capital Territory 2601, Australia.
authors.forename: Sara
authors.initials: S
authors.lastname: Marzban
authors.affiliation: Laser Physics Centre, Australian National University, Canberra, Australian Capital Territory 2601, Australia.|Centre for Quantum Computation and Communication Technology, Laser Physics Centre, Australian National University, Canberra, Australian Capital Territory 2601, Australia.
authors.forename: John G
authors.initials: JG
authors.lastname: Bartholomew
authors.affiliation: Laser Physics Centre, Australian National University, Canberra, Australian Capital Territory 2601, Australia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Madden
authors.affiliation: Laser Physics Centre, Australian National University, Canberra, Australian Capital Territory 2601, Australia.
authors.forename: Khu
authors.initials: K
authors.lastname: Vu
authors.affiliation: Laser Physics Centre, Australian National University, Canberra, Australian Capital Territory 2601, Australia.|Centre for Quantum Computation and Communication Technology, Laser Physics Centre, Australian National University, Canberra, Australian Capital Territory 2601, Australia.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Sellars