Low-Threshold Lasing up to 360 K in All-Dielectric Subwavelength-Nanowire Nanocavities

Abstract

The ultrasmall dimensions of subwavelength nanowires have made them ideal candidates for compact and energy-efficient photonic applications and have, in particular, led to the realization of a large range of plasmonic nanolasers. Ohmic losses and short propagation lengths in metal-based plasmonic platforms, however, limit their performance. In this work, we bypass such limitations by relying instead on an all-dielectric platform: subwavelength ZnO nanowire-induced cavities integrated in SiN photonic crystal waveguides. Because of the low optical losses of this fully dielectric nanocavity, we demonstrate low-threshold lasing at high-temperatures using subwavelength nanowires as the gain material. Investigated devices consistently outperform their plasmonic counterparts in terms of lasing threshold (Pth = 3.5 MW·cm–2) and all existing subwavelength-nanowire lasers in terms of operation temperature (T = 360 K). Such a performance demonstrates the high potential of this all-dielectric platform for integrated photonic applications with low energy costs.