GaAs/AlxGa1-xAs quantum cascade lasers
Abstract
A unipolar injection quantum cascade (QC) laser grown in an AlGaAs/GaAs material system by molecular beam epitaxy, is reported. The active material is a 30 period sequence of injectors/active regions made from Al0.33Ga0.67As/GaAs-coupled quantum wells. For this device a special waveguide design, which complies with a GaAs heavily doped substrate and very short Al0.90Ga0.10As cladding layers, has been optimized. At a heat-sink temperature of 77 K, the laser emission wavelength is 9.4 μm with peak optical power exceeding 70 mW and the threshold current density is 7.3 kA/cm2. The maximum operating temperature is 140 K. This work experimentally demonstrates the general validity of QC laser principles by showing laser action in a heterostructure material different from the one used until now.
- Publication:
-
Applied Physics Letters
- Pub Date:
- December 1998
- DOI:
- 10.1063/1.122812
- Bibcode:
- 1998ApPhL..73.3486S
- Keywords:
-
- 42.60.By;
- 42.55.Px;
- 42.82.Et;
- Design of specific laser systems;
- Semiconductor lasers;
- laser diodes;
- Waveguides couplers and arrays