Growth and Spectroscopy of Lanthanide Doped Y${}_2$SiO${}_5$ Microcrystals for Quantum Information Processing

Lanthanide-doped Y${}_2$SiO${}_5$ microcrystals were prepared using the solution combustion, solid state and sol-gel synthesis techniques. Of these, the sol-gel method yields the most reliable and high-quality X2 phase Y${}_2$SiO${}_5$ microcrystals. Absorption and laser site-selective fluorescence measurements of Nd${}^{3+}$, Eu${}^{3+}$ and Er${}^{3+}$ doped material, performed at cryogenic temperatures, indicate that the as-grown microcrystals are of high optical quality with inhomogeneously broadened optical linewidths that are comparable to bulk crystals at similar dopant concentrations.