Second-harmonic generation in GaAs-based quantum-cascade lasers grown on <100> substrates

Emission of coherent light at 5.1 /spl mu/m wavelength from GaAs-based quantum cascade lasers is reported. This was achieved by integrating nonlinear cascades with large second-order susceptibility in the active regions of the laser.     

High-power long-wavelength room-temperature MOVPE-grown quantum cascade lasers with air-semiconductor waveguide

Quantum cascade lasers grown by metal organic vapour phase epitaxy (MOVPE) with high peak output power of 1.3 W at 300 K emitting a wavelength of 9.8 mum are reported. The devices are processed in wide ridge waveguide structures with an air-semiconductor interface to confine the laser optical mode. This design increases the optical overlap factor and reduces waveguide losses.     

Widely tunable high-power external cavity quantum cascade laser operating in continuous-wave at room temperature

A grating-coupled external cavity quantum cascade laser operating in continuous-wave at room temperature is reported. Single-frequency operation tunable over more than 160 cm^-1 around the centre wavelength of 4.6 mum has been observed at a chip temperature of 300 K. The maximum optical power at the gain peak was 300 mW, corresponding to a wall-plug efficiency of 6 %. Observed power output at the gain bandwidth edges was in excess of 125 mW.     

Room-temperature continuous-wave operation of long wavelength (l ?9.5 lm) MOVPE-grown quantum cascade lasers

High-power continuous-wave operation of long wavelength quantum cascade lasers grown by metal organic vapour phase epitaxy is reported. The lasers have been processed as buried heterostructures with thick gold-plated contacts. The devices emit at a wavelength of 9.5 mum with output powers of several hundreds of milliwatts at room temperature.