Quantum-Cascade Lasers with a Distributed Bragg Reflector Formed by Ion-Beam Etching

Single-mode lasing of quantum-cascade lasers with a distributed Bragg reflector formed by ion-beam etching in layers of the upper waveguide cladding is demonstrated. The active region is formed based on an In0.53Ga0.47As/Al0.48In0.52As solid-alloy heteropair with two-phonon depletion of the lower level in the cascade. Single-mode lasing at a temperature of 280 K corresponds to the emission wavelength of 7.74 μm, and the side-mode suppression ratio is 24 dB.