Quantum cascade lasers: high-power emission and single-mode operation in the long-wave infrared (λ>6 μm)

We present an overview of our recent results on the growth, fabrication, and characterization of high-power long-wave infrared quantum cascade lasers with multimode and single-mode waveguides. Powers of up to 1.2 W at wavelengths of = 6.1 µm are obtained with InGaAs/InAlAs buried heterostructure lasers grown lattice matched on InP substrates. For longer wavelengths, up to = 9 µm, powers of P = 800 mW are delivered from room-temperature-operated devices. Distributed-feedback waveguides have been fabricated with buried grating geometry, leading to single-mode emission of more than P = 150 mW output at = 7.74 µm when the device is operated at room temperature in continuous mode.