${\rm In}_{0.75}{\rm Ga}_{0.25}{\rm As}/{\rm InP}$ Multiple Quantum-Well Discrete-Mode Laser Diode Emitting at 2 $\mu{\rm m}$

A discrete-mode laser diode fabricated in the InGaAs/InP multiple quantum-well system and emitting single mode at λ = 2 μm is reported. The laser had an ex-facet output power >;5 mW at 25 °C and the laser operated mode-hop free in the temperature range -5 °C-55 °C.