Angular-momentum coupling of optical whispering-gallery modes to liquid droplet microresonators
Authors: D’Ambrosio D., Zambrana-Puyalto X., Capezzuto M., Giorgini A., Malara P., Avino S., Gagliardi G.
Autors Affiliation: Consiglio Nazionale delle Ricerche, Istituto Nazionale di Ottica (INO), via Campi Flegrei 34, Comprensorio A. Olivetti, I-80078 Pozzuoli, Italy; Istituto Italiano di Tecnologia, Via Morego 30, 16136 Genova, Italy
Abstract: Starting from a recently developed model based on the generalized Lorenz-Mie theory, we simulate and experimentally investigate the resonance spectrum and the scattered light field of whispering-gallery modes (WGMs) in a liquid droplet excited with a free-space visible laser beam. Depending on the illumination configuration and the spectral region, we observe WGMs with diverse quality factors and coupling efficiencies. Through imaging of scattering patterns, we show a robust agreement between theory and experiment. Our study provides an insight of the free-space optical coupling phenomenon, opening pathways for a controlled excitation of ultrahigh-quality WGMs in a plethora of liquid and solid optical microresonators for sensing and imaging applications.
Journal/Review: PHYSICAL REVIEW A
Volume: 104 (4) Pages from: 043504-1 to: 043504-6