Abstract

Spin-polarized vertical-cavity surface-emitting lasers (Spin-VCSELs) are highly interesting devices for optical communications providing novel characteristics like the capability for ultrafast polarization oscillations [1]. The frequency of these oscillations is independent of classical intensity relaxation oscillations and has the potential to exceed the frequency of 100 GHz. The oscillations evolve due to coupling of the carrier-spin-photon system via the optical selection rules. VCSELs usually offer two orthogonally linearly polarized cavity modes which have a frequency splitting determined mainly by the birefringence in the laser cavity. In conventional spin-unpolarized VCSELs typically only one of these modes is lasing. By injecting spin-polarized carriers both modes lase simultaneously which leads to an emission of circularly polarized light. Since the frequency of both modes is different in birefringent VCSELs, the circular polarization degree is oscillating with the difference frequency.

© 2015 IEEE