Long-wavelength lasing from InAs self-assembled quantum dots on (311) B InP

Abstract
Nanometer-scale InAs quantum dots were grown on InP by self-assembly using gas-source molecular beam epitaxy. InAs depositions of 0.33 nm in nominal thickness were found to form quantum dots on (311) B InP with a lateral dimension of about 43 nm and a density of 2×1010 cm−2. A laser structure with seven periods of the quantum dot active layers lased in a wavelength range from 1.1 to 1.4 μm at 77 K under pulsed current injection. The lasing wavelength changed to a shorter wavelength as the cavity length decreased, indicating gain saturation due to state filling effect in discrete quantum levels, which is typical in quantum dot lasers. This phenomenon can be used to achieve wide-range multiwavelength lasers for optical communication, that can be adjusted merely by changing the effective cavity length.