Erbium-implanted silica microsphere laser

Spherical silica optical microresonators were doped with erbium ions by ion implantation at energies of 925 keV and 2.05 MeV using a rotating stage. After thermal annealing at 800 degrees C, light was coupled into the microsphere using a tapered optical fiber. An optical quality factor as high as 1.9 X 10(7) was observed at lambda = 1450 nm, corresponding to a modal loss of only 0.01 dB/cm. When pumped at 1450 nm, multi-mode lasing around 1570 urn is observed at a threshold between 150 and 250 mu W depending on the overlap between mode and Er distribution. This work demonstrates the compatibility of ion implantation and microresonator technology. (c) 2005 Elsevier B.V. All rights reserved.