Progress towards the development of rare-earth doped waveguides for quantum communications applications

Photon echo measurements were conducted on the
³
H
4
→
⁷
D
2
transition of Pr
³⁺
, on a slab waveguide of TeO
2
deposited on a substrate of 0.005%Pr
³⁺
: Y
2
SiO
5
. Optical coherence times of 62µs were observed, which is consistent with the bulk sample value of 111µs, given the level of instantaneous spectral diffusion. The results indicate that planar waveguide technology could be utilized for quantum communication purposes.