GaAs/AlGaAs (~9.4 [mu]m) quantum cascade lasers operating at 260 K

Abstract

GaAs/AlGaAs (~9.4 μm) quantum cascade lasers operating at 260 K

The fabrication of Quantum Cascade Lasers (QCLs) emitting at ~9.4 μm is reported. The devices operated in pulsed mode at up to 260 K. The peak powers recorded in 77 K were over 1 W, and the slope efficiency η [approximate] 0.5-0.6 W/A per uncoated facet. This has been achieved by the use of GaAs/Al[0.45]Ga[0.55]As heterostructure, with 3QW anticrossed-diagonal design originally proposed by Page et al. [1]. Double plasmon planar confinement with Al-free waveguide has been used to minimize absorption losses. The double trench lasers were fabricated using standard processing technology, i.e., wet etching and Si[3]N[4] for electrical insulation. The QCL structures have been grown by Molecular Beam Epitaxy (MBE), with Riber Compact 21T reactor. The stringent requirements - placed particularly on the epitaxial technology - and the influence of technological conditions on the device structure properties are presented and discussed in depth.