Category Archives: Publications

Operation of continuous wave quantum cascade lasers with a frequency-shifted feedback provided by an acousto-optic modulator is reported. Measured linewidth of 1.7 cm−1 for these devices, under CW operating conditions, was in a good agreement with predictions of a model based on frequency-shifted feedback seeded by spontaneous emission. Linewidth broadening was observed for short sweep […]

The recent demonstration of external cavity quantum cascade lasers with optical feedback, controlled by an acousto-optic modulator, paves the way to ruggedized infrared laser systems with the capability of tuning the emission wavelength on a microsecond scale. Such systems are of great importance for various critical applications requiring ultra-rapid wavelength tuning, including combustion and explosion […]

5.6 μm quantum cascade lasers based on the Al0.78In0.22As/In0.69Ga0.31As active region composition with the measured pulsed room temperature wall plug efficiency of 28.3% are reported. Injection efficiency for the upper laser level of 75% was measured for the design by testing devices with variable cavity lengths. A threshold current density of 1.7 kA/cm2 and a […]

We report simultaneous two wavelength operation of an acousto-optically tuned quantum cascade laser (QCL). The two wavelengths can be independently tuned as well as independently switched, retaining the submicrosecond switching capability. In addition, we have used the two wavelength operation as a tool for the direct measure of the lifetimes of the lasing states in […]

5.6 μm quantum cascade lasers based on Al 0.78 In 0.22 As/In 0.69 Ga 0.31 As active region composition with measured pulsed room temperature wall plug efficiency of 28.3% are reported. Injection efficiency for the upper laser level of 75% was measured for the new design by testing devices with variable cavity length. Threshold current […]

5.6μm quantum cascade lasers based on Al0.78In0.22As/In0.69Ga0.31As active region composition with measured pulsed room temperature wall plug efficiency of 28.3% are reported. Injection efficiency for the upper laser level of 75% was measured by testing devices with variable cavity length. Threshold current density of 1.7kA/cm2 and slope efficiency of 4.9W/A were measured for uncoated 3.15mm […]

The recent demonstration of external cavity quantum cascade lasers with optical feedback, controlled by an acousto-optic modulator, paves the way to ruggedized infrared laser systems with the capability of tuning the emission wavelength on a microsecond scale. Such systems are of great importance for various critical applications requiring ultra-rapid wavelength tuning, including combustion and explosion […]

Experimental data for 15-stage 5.6-μm quantum cascade lasers based on Al0.78In0.22As/In0.69Ga0.31As active region composition are presented. Pulsed slope efficiency, threshold current density, and wall-plug efficiency for a 2.1 mm × 10.4 μm device with a high reflection-coated back facet were measured to be 1.45 W/A, 3.1 kA/cm2, and 18%, respectively. Corresponding continuous wave values for […]

Experimental data for 15-stage 5.6-μm quantum cascade lasers based on Al0.78In0.22As/In0.69Ga0.31As active region composition are presented. Pulsed slope efficiency, threshold current density, and wall-plug efficiency for a 2.1 mm × 10.4 μm device with a high reflection-coated back facet were measured to be 1.45 W/A, 3.1 kA/cm2, and 18%, respectively. Corresponding continuous wave values for […]

Experimental and model results for 15-stage broad area quantum cascade lasers (QCLs) are presented. Continuous wave (CW) power scaling from 1.62 to 2.34 W has been experimentally demonstrated for 3.15-mm long, high reflection-coated QCLs for an active region width increased from 10 to 20 μm. A semiempirical model for broad area devices operating in CW […]