High power, broad tuning, double-stack quantum cascade laser at λ ∼ 6.9 µm

Abstract

Broadband double-stack quantum cascade lasers with strain-balanced In0.60Ga0.40As/In0.43Al0.57As and In0.60Ga0.40As/In0.41Al0.59As emitting at a wavelength of 6.9 µm are reported. The double-stack design is achieved by changing the beam flux of the aluminum effusion cell. The maximum continuous-wave power at room temperature (293 K) is 1.07 W. Tuning ranges of 195 and 104 cm−1 in pulsed and continuous-wave modes, respectively, are obtained using an external-cavity measurement system. The continuous-wave power of the external-cavity mode exceeds 110 mW, and is thus suitable for the detection of some functional groups.