Polarization dynamics in spin‐VCSELs with integrated surface grating for high birefringence splitting

Abstract

Polarization dynamics in spin-polarized vertical-cavity surface-emitting lasers (spin-VCSELs) with high birefringence have recently been demonstrated to offer very high potential for optical data-transmission systems that outperform their counterparts based on conventional direct current modulation by far. For polarization dynamics in spin-VCSELs, the birefringence determines the resonance frequency and thus the modulation bandwidth. In previous work, birefringence was controlled using mechanical strain, which lacks the ability to be integrated in standard VCSEL manufacturing processes. In this work the polarization dynamics of a VCSEL with an integrated birefringence control mechanism is demonstrated based on custom designed integrated surface gratings. It is found that, despite the surface grating which is commonly known to stabilize the polarization, the presented spin-VCSELs are able to generate polarization oscillations with frequencies corresponding to the birefringence induced by the surface grating and show polarization dynamics up to 68 GHz.