High Stability Near-infrared Microsphere Laser Doped with Ho<sup>3+</sup> Ions

Abstract In this paper a microscale near-infrared microsphere laser was demonstrated based on a phase-separat ed glass matrix doped with Ho 3+ ions.The glass microsphere with a diameter of 42. 81 m was fabricated exhibiting a high optical quality factor (Q) of 1. 25 10 6 and a high damage threshold.Pump light was coupled into the micro sphere using a tapered optical fiber resulting in efficient excitation of the rare-earth ions and single-mode laser emission at 2. 04 m was observed from the microspherical resonator.Additionally the glass transition temperature (T g ) was employed as an indicator of the device' s resistance to laser-induced damage confirming that stable opera tion can be achieved under complex environmental conditions.Key words Ho 3+ ion