Tailored hypersound generation in single plasmonic nanoantennas

FABRICIO DELLA PICCA; RODRIGO BERTE; RAHMANI, MOHSEN; PABLO ALBELLA; JUAN M BUJJAMER; MARTÍN POBLET; EMILIANO CORTÉS; STEFAN A. MAIER; ANDREA V. BRAGAS

NANO LETTERS (PRINT)

AMER CHEMICAL SOC

Lugar: Washington; Año: 2016 vol. 16 p. 1428 - 1434

1530-6984

Ultrashort laser pulses impinging on a plasmonicnanostructure trigger a highly dynamic scenario in theinterplay of electronic relaxation with lattice vibrations, whichcan be experimentally probed via the generation of coherentphonons. In this Letter, we present studies of hypersoundgeneration in the range of a few to tens of gigahertz on singlegold plasmonic nanoantennas, which have additionally beensubjected to predesigned mechanical constraints via silicabridges. Using these hybrid gold/silica nanoantennas, wedemonstrate experimentally and via numerical simulations howmechanical constraints allow control over their vibrationalmode spectrum. Degenerate pump−probe techniques withdouble modulation are performed in order to detect the smallchanges produced in the probe transmission by the mechanicaloscillations of these single nanoantennas.