Cold and Hot Spots: From Inhibition to Enhancement by Nanoscale Phase Tuning of Optical Nanoantennas

Year: 2020

Authors: Blascetta Nicola Palombo; Lombardi Pietro; Toninelli Costanza; van Hulst Niek F.

Autors Affiliation: Barcelona Inst Sci & Technol, Inst Ciences Foton, ICFO, Barcelona 08860, Spain; European Lab Nonlinear Spect, CNR INO, I-50019 Florence, Italy; European Lab Nonlinear Spect, LENS, I-50019 Florence, Italy; Inst Catalana Recerca & Estudis Avancats, ICREA, Barcelona 08010, Spain.

Abstract: Optical nanoantennas are well-known for the confinement of light into nanoscale hot spots, suitable for emission enhancement and sensing applications. Here, we show how control of the antenna dimensions allows tuning the local optical phase, hence turning a hot spot into a cold spot. We manipulate the local intensity exploiting the interference between driving and scattered field. Using single molecules as local detectors, we experimentally show the creation of subwavelength pockets with full suppression of the driving field. Remarkably, together with the cold excitation spots, we observe inhibition of emission by the phase-tuned nanoantenna. The fluorescence lifetime of a molecule scanned in such volumes becomes longer, showing slow down of spontaneous decay. In conclusion, the spatial phase of a nanoantenna is a powerful knob to tune between enhancement and inhibition in a 3-dimensional subwavelength volume.

Journal/Review: NANO LETTERS

Volume: 20 (9)      Pages from: 6756  to: 6762

More Information: N.F.v.H. acknowledges the financial support by the European Commission (ERC Advanced Grant 670949-LightNet), the Spanish Ministry of Science, Innovation & Universities (MCIU/AEI: PGC2018-096875-B-I00), the Ministry of Economy (“Severo Ochoa” program for Centers of Excellence in R&D SEV-2015-0522 and Plan Nacional F152015 -69258P), the Catalan AGAUR (2017SGR1369), Fundaci6 Privada Cellex, Fundaci6 Privada Mir-Puig, and Generalitat de Catalunya through the CERCA program. N.P.B. acknowledges the Ministry of Economy (MINECO) for support of the FPI fellowship. C.T. thanks the COST Action Nanoscale Quantum Optics (MP1403) and acknowledges financial support from the MIUR program Q-Sec and Ente Cassa di Risparmio di Firenze (GRANCASSA). P.L. and C.T. acknowledge support from ERANET COFUND action PhotonicSensing (FASPEC project, PS -2016_22).
KeyWords: local phase; near field interference; hot spot – cold spot; antenna enhancement; inhibition of emission; local density of states; superresolution; nanoantenna; plasmonics; single molecule
DOI: 10.1021/acs.nanolett.0c02607

Citations: 5
data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-11-17
References taken from IsiWeb of Knowledge: (subscribers only)
Connecting to view paper tab on IsiWeb: Click here
Connecting to view citations from IsiWeb: Click here