Wavelength and threshold current of a quantum well laser in a strong magnetic field

Abstract

The threshold current and the wavelength of a high-power ridge waveguide AlGaAs graded index seperate confinement heterostructure quantum well laser have been studied in strong magnetic fields up to 20 T, to simulate the complete quantum confinement of carriers in a quantum box laser. It will be shown both experimentally and theoretically that the threshold current is increased by the application of a strong magnetic field, while its temperature sensitivity is reduced. It will further be shown that at low temperatures (T<100 K) laser emission occurs via both free carrier and excitonic transitions, while at higher temperatures (T>100 K) exciton laser emission is only observed after application of a strong magnetic field, i.e., reduction of the dimensionality.