We report room-temperature amplified spontaneous emission and spectral narrowing at infrared wavelengths in solution-processed films made up of PbS quantum-dot nanocrystals. The results are relevant to optical amplification and lasing integrated upon a variety of substrates. The active optical medium operates at room temperature without any additional matrix material, providing an optical gain of 260 cm^-1 and a pump threshold of 1 mJ/cm^-2. Nanocrystals synthesized in an aqueous solution and stabilized by use of short ligands result in high quantum-dot volume fractions in solid films and in a redshift emission relative to absorption.
© 2005 Optical Society of America
(130.0130) Integrated optics : Integrated optics
(140.3070) Lasers and laser optics : Infrared and far-infrared lasers
(250.0250) Optoelectronics : Optoelectronics
(250.4480) Optoelectronics : Optical amplifiers
V. Sukhovatkin, S. Musikhin, I. Gorelikov, S. Cauchi, L. Bakueva, E. Kumacheva, and E. H. Sargent, "Room-temperature amplified spontaneous emission at 1300 nm in solution-processed PbS quantum-dot films," Opt. Lett. 30, 171-173 (2005)