Polarization-dependent photoluminescence properties of fab-compatible nanowire-based nanophotonic structures

Abstract

Semiconductor nanowires show great potential for controlling light–matter interactions. Moreover, their polarization-dependent optical properties, primarily enabled by their dielectric mismatch, are a significant requisite for a plethora of emerging applications spanning from polarized photodetection to quantum photonics and quantum communication. Herein, we study the polarization dependence of photoluminescence (PL) properties from fab-compatible nanophotonic structures, comprising arrays of ultrathin (20 nm) silicon carbide nanowires (NWs) doped with oxygen and erbium ions. Polarization-resolved PL studies demonstrate a significant excitation polarization anisotropy (∼0.7) of the visible NW PL for light polarized parallel and perpendicular to the NWs' long axis. This anisotropic behavior agrees with our simulations and with the classical dielectric contrast model and is consistent across the investigated periodicity range of the NW arrays. Furthermore, the effect of this anisotropy on the NW carrier dynamics is explored through power-dependence and transient PL measurements. We have observed a faster carrier lifetime for light polarized parallel to the NWs than the perpendicular polarization. Finally, we demonstrate a translation of this polarization dependence to the technologically significant erbium-induced 1540 nm emission from the erbium centers in the NW arrays. The ability to engineer emission polarization and placement of these centers in the NW array offers a promising platform for emission enhancement of telecom emitters through effective coupling to optical nanocavities for applications in chip-scale photonics and quantum photonics.