Short-wavelength (λ≈3.05 μm) InP-based strain-compensated quantum-cascade laser

The design and implementation of a short-wavelength quantum-cascade laser based on the strain-compensated In0.73Ga0.27As-In0.55Al0.45As-AlAs heterosystem on InP is described. Lasers with a reduced level of doping in the active region require a larger bias voltage and emit at shorter wavelength; the emission wavelength is 3.05 mu m at T approximate to 80 K. The lasers operate up to T approximate to 150 K and electroluminescence persists up to room temperature, where the peak position is close to 3.3 mu m. The short-wavelength limit of such lasers is evaluated based on the dependence of their maximum operation temperatures and on the probable energies of the indirect valleys in the active region. (c) 2007 American Institute of Physics.