Erbium-implanted silica microsphere laser

Abstract

Spherical silica optical microresonators were doped with erbium ions by ion implantation at energies of 925keV and 2.05MeV using a rotating stage. After thermal annealing at 800°C, light was coupled into the microsphere using a tapered optical fiber. An optical quality factor as high as 1.9×107 was observed at λ=1450nm, corresponding to a modal loss of only 0.01dB/cm. When pumped at 1450nm, multi-mode lasing around 1570nm is observed at a threshold between 150 and 250μW depending on the overlap between mode and Er distribution. This work demonstrates the compatibility of ion implantation and microresonator technology.