Study of the Spectra of Arched-Cavity Quantum-Cascade Lasers

The temperature characteristics of arched-cavity quantum-cascade lasers with different geometrical dimensions emitting in the spectral range of 7–8 μm are studied. The laser heterostructure was grown by molecular-beam epitaxy. The active region consisted of 50 cascades based on a heteropair of In 0.53 Ga 0.47 As/Al 0.48 In 0.52 As solid alloys. Single-mode lasing is demonstrated for lasers with the semicircular cavity segment 100 μm in diameter and the linear segment 1 mm long. The maximum side-mode suppression ratio at a temperature of 290 K was 26 dB, and the emission wavelength was 7.73 μm.