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Examines the facet temperature profile and the thermal resistance of operating quantum-cascade lasers using a microprobe band-to-band photoluminescence technique. Dependence of thermal resistance of continuous wave or pulsed injection conditions; Thermal conductivity of the active region.

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 µm 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. [ABSTRACT FROM AUTHOR]

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 µm with output powers of several hundreds of milliwatts at room temperature. [ABSTRACT FROM AUTHOR]

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 µm 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. [ABSTRACT FROM AUTHOR]

Quantum cascade lasers designed to emit at λ≃19 µm grown by metal organic vapour phase epitaxy are demonstrated to operate in pulsed mode up to 170 K. The structures are processed into a double-metal waveguide that enhances mode confinement while minimising waveguide losses. The performance of the material grown at rates of 6 and 1 Å/s is compared. The devices constitute the longest-wavelength quantum cascade lasers grown by metal organic vapour phase epitaxy to date. [ABSTRACT FROM AUTHOR]

A correction to the article "Room-temperature continuous-wave operation of long wavelength (λ=9.5 μm) MOVPE-grown quantum cascade lasers" that was published in the previous issue is presented.

Quantum cascade lasers grown by metal organic vapuor phase epitaxy are demonstrated to work in continuous mode up to room temperature. The lasers have been processed as buried heterostructures with thick gold plating on the top contact. Continuous-wave output powers of 20 mW are obtained at 300 K with threshold current densities of 3.9 kA/cm². [ABSTRACT FROM AUTHOR]

Semiconductor microstructures can be used to tailor the dispersion properties of surface plasmon polaritons in the terahertz (THz) frequency range, and therefore can be used as important building blocks for terahertz optical devices. The physical principles of three structures are discussed: plasmonic second-order gratings, designer (spoof) surface plasmon polariton structures, and channel polariton structures. The effectiveness of these structures is demonstrated by utilising them to improve power throughput and to reduce the beam divergence of edge-emitting THz quantum cascade lasers. Plasmonics promises compact and low-loss solutions for manipulating light at THz wavelengths, and will have a large impact on applications such as imaging, light detection and ranging (LIDAR), and the heterodyne detection of chemicals. [ABSTRACT FROM AUTHOR]

A correction to the article "Double-metal waveguide 19 λ ≈ μm quantum cascade lasers grown by metal organic vapour phase epitaxy'," that was published in the 2007 issue is presented.