Polarization multiplexing in VCSEL-arrays

Abstract

Advancements to our VCSEL technology platform now allow to dynamically switch between two orthogonal polarization states on a single VCSEL-array chip. Here stable and linearly polarized emission is combined without change to the VCSEL optical characteristics. This is rendered possible by 90°-rotated surface-gratings for each channel to realize polarization locking in one of the two polarization directions. Similar high polarization extinction ratios, thresholds and output powers are attained for each channel. Furthermore, electrical routing enables the flexible definition of illumination zones consisting of sub-arrays of VCSELs with the same polarization orientation. Time-division polarization multiplexing is thus enabled by addressing different zones of the VCSEL array for dynamic illumination concepts.Our vision marks this as the next step in increasing the functionality per VCSEL chip area without decreasing yield or lifetime constraints in high-volume manufacturing.