Phonon-terminated laser emission from Ni^2+ ions in KMgF_3

Abstract

The optical properties of Ni(2+) ions in the cubic host KMgF(3) are reported. Phonon-terminated laser emission is observed for the first reported time in Ni:KMgF(3) at 1.591 microm at 77 K. Despite characteristics favorable for continuous tunability at room temperature, laser emission is not observed at temperatures >/=195 K. Indirect evidence indicates that excited-state absorption reduces gain over the long-wavelength portion of the vibronic sideband and is stronger in Ni:KMgF(3) than in Ni:MgF(2).