Single-mode tunable, pulsed, and continuous wave quantum-cascade distributed feedback lasers at λ≅4.6–4.7 μm

Single-mode tunable quantum-cascade distributed feedback lasers emitting at 4.6–4.7 μm wavelength are reported. The lasers employ strained heterostructure material with global strain compensation to provide the large band offset needed for high-performance short wavelength operation. Pulsed, continuously tunable single-mode emission is achieved from 90 to 300 K with a tuning range of 65 nm. Peak output power levels of 100 mW at room temperature are obtained. In continuous-wave operation, current tunable single-mode emission is demonstrated around liquid-nitrogen temperature with a tuning range of 20 nm (over a current range of 450 mA). The maximum output power in continuous wave at 80 K is 150 mW.