Room-temperature near-infrared up-conversion lasing in single-crystal Er-Y chloride silicate nanowires

Near-infrared up-conversion lasing in erbium(Er)-yttrium(Y) chloride silicate nanowires was demonstrated when pumped by 1476 nm laser at room temperature. The emission covers a very wide wavelength range (400-1000 nm). A clear threshold for 985 nm peak was observed at a launched average pump power of approximately 7 mW. Above threshold, the intensity increases linearly when turning up the pump power. The full width at half maximum at 985 nm decreases from 1.25 nm to 0.25 nm when reducing the measurement temperature from 30 K to 7 K, which is the narrowest linewidth of 980 nm micro-lasers to date. Our demonstration presents a possible novel method of utilizing up-conversion mechanism in Er-Y nanowire to achieve tunable near-infrared laser, which breaks new ground in the exploration of nanoscale optoelectronic devices operating at near-infrared wavelength.