Low-Threshold Strained Quantum-Well GaSb-Based Lasers Emitting in the 2.5- to 2.7- $\mu$ m Wavelength Range

GaInAsSb-GaSb strained quantum-well (QW) ridge waveguide diode lasers emitting in the wavelength range from 2.51 to 2.72 mum have been grown by molecular beam epitaxy. The devices show ultralow threshold current densities of 44 A/cm² (L rarr infin) for a single QW device at 2.51 mum, which is the lowest reported value in continuous-wave operation near room temperature (15degC) at this wavelength. The devices have an internal loss of 3 cm^-1 and a characteristic temperature of 42 K. By using broader QWs, wavelengths up to 2.72 mum could be achieved.