Design and Characterization of Low-Threshold InP Nanowire Photonic Crystal Surface-Emitting Lasers

This study examines the lasing performance of optically pumped wurtzite-phase InP nanowire (NW) photonic crystal surface-emitting lasers (PCSELs) with the goal of optimizing the cavity design for low-threshold lasing. By varying the photonic crystal lattice constant and NW diameter, this study systematically investigates the threshold power and the threshold gain. Using finite-difference time-domain simulations and gain spectra modeling, this study finds that the lowest pump threshold occurs when the cavity resonance energy is slightly above the spontaneous emission maximum energy due to high differential gain. Furthermore, PCSEL structures with an apothem-to-pitch ratio of ≈0.15 are advantageous because they provide increased confinement factors, resulting in the lowest lasing threshold and high laser output. This study paves the path toward low-threshold NW PCSEL designs for photonic integrated circuits.