Sci. Adv. 5, eaat8896 (2019)

The development of miniature semiconductor lasers that cover the entire telecom-band wavelength range from 1.2 to 1.6 μm is desirable for optical fibre communication systems. Now, Guoqiang Zhang and co-workers from NTT Corporation, Japan have demonstrated optically pumped InP/InAs nanowire lasers that operate in this region with an exact wavelength that can be controlled by changing the thickness of the InAs quantum-well layer from 6.8 to 9.0 nm. The nanowire diameter and length were about 1 μm and 10 μm, respectively. High compressive strain was introduced in the InAs layers by the high lattice mismatch (3.1%) of the InP/InAs material system, in order to increase optical gain. The nanowires were excited by a picosecond laser emitting at 800 nm wavelength. The excitation-power-dependent photoluminescence measurements at room temperature revealed the lasing threshold at the excitation power to be in the range of 1.4 to 4.2 mJ cm–2. Laser emission between 1.3 to 1.5 μm was observed.