Spin-Polarized Edge-Emitting Lasers*

Semiconductor lasers driven by a spin-polarized current are expected to provide a threshold current reduction, optical polarization control, and intensity stabilization. We explore these possibilities in edge-emitting lasers where the low switching fields of in-plane magnetized Fe thin films should enable electronic modulation of the output polarization. Fe/AlGaAs/GaAs heterostructures are designed, grown, and fabricated into surface-emitting light-emitting diodes (LEDs) and double heterostructure lasers. The LED emission is dominated by an H-band feature at 5 K and by the bulk recombination feature at 20 K. An electron spin polarization of 24{\%} is measured in the Faraday geometry. Oxide-stripe lasers are fabricated with and without an Fe capping layer. Lasing is observed at low temperatures with threshold current densities of $\sim $100 A/cm$^{2}$. Magnetic field-dependent studies to examine the effects of spin injection on laser performance will be discussed.