InGaAs ∕ AlAsSb quantum cascade lasers

Abstract

The In0.53Ga0.47As∕AlAs0.56Sb0.44 heterostructure system is of significant interest for the development of high-performance intersubband devices due to its very large conduction band offset (ΔEc∼1.6eV) and lattice-matched compatibility with well-established InP-based waveguide technology. In this letter, we report the realization of In0.53Ga0.47As∕AlAs0.56Sb0.44 quantum cascade lasers emitting at λ∼4.3μm. The highest-performance devices have low-temperature (20K) threshold currents of ∼6kA∕cm2 and display laser action up to a maximum temperature of 240K, with a characteristic temperature of T0∼150K.

Investigation of Thermal Effects in Quantum-Cascade Lasers

“…Recently InGaAs-AlAsSb QCLs lattice matched to InP substrates have been reported [8]. The InGaAs-AlAsSb heterostructure has a very large conduction band offset of 1.6 eV which is almost double that of the strained InGaAs-AlInAs heterostructure and makes this material system inherently less sensitive to temperature.…”

Influence of doping density on electron dynamics in GaAs∕AlGaAs quantum cascade lasers

“…12 Moreover, laser operation has been reported on other material systems, i.e., AlGaAs on a GaAs substrate 13 and Al͑Ga͒Sb on InAs. 14 Devices with Sb-containing barriers on both InAs substrate [14][15][16] as well as on InP substrate [17][18][19] are promising for either increasing the electron confinement or reducing the emission wavelength, and above room temperature pulsed operation on both substrates was recently reported. 16,18 Since the realization 13 of the GaAs-based quantum cascade laser, an impressive extension of the attainable infrared frequency range has been achieved and can be operated at wavelengths as long as 160 m. 20 The design of QCLs based on GaAs/ AlGaAs can be made very flexible by varying the Al content due to naturally occurring near lattice matched material system across the full range of Al contents.…”

Thermal effects in InGaAs/AlAsSb quantum-cascade lasers

“…Recently InGaAs/AlAsSb QCLs lattice matched to InP substrates have been reported [7]. The InGaAs/AlAsSb heterostructure has a very large conduction band offset of ∼1.6 eV which is almost double that of the strained InGaAs/AlInAs heterostructure and makes this material system inherently less sensitive to temperature.…”