PeroSeminar | 15 October 2026

Abstract: This work presents a systematic study of the optical properties of gallium phosphide (GaP) nanowires (NWs) and structures based on them, relevant for integrated photonics. The study is divided into three parts.

First, the resonant properties of vertical GaP NWs are examined. Using FDTD simulations and dark-field spectroscopy, Mie-type resonances are shown to be tunable from 400 to 900 nm by varying the NW diameter from 50 to 200 nm, with experimental spectra from MBE-grown NW arrays confirming the calculations. Second, the waveguide effect in planarized horizontal GaP NWs is investigated. The fundamental HE₁₁ mode exhibits cutoff at diameters of 108, 135, and 185 nm for wavelengths of 532, 633, and 808 nm. A 2×2 directional coupler based on bent NWs is fabricated, and numerical modeling demonstrates controllable spatially periodic energy transfer governed by the coupler geometry. Third, nanoscale light sources based on heterostructured GaP/GaPₓAs₁₋ₓ NWs and a hybrid GaP/MoS₂ structure are studied. μ-PL spectroscopy and simulations reveal efficient localization and guiding of emission along the NW with pronounced Fabry–Pérot oscillations. The hybrid structure enables a locally enhanced, highly directional emitter, with the NW acting as a Fabry–Pérot resonator (Q ≈ 360) and permitting remote optical excitation of MoS₂.