Photothermal heterodyne holography of gold nanoparticles.
We report a method based on heterodyne numerical holography associated to photothermal excitation for full field and three-dimensional localisation of metallic nanoparticles. A modulated pump laser (lambda = 532 nm) heats several particles, creating local refractive index changes. This modulation is detected using a probe and a local oscillator beam (lambda = 785 nm), frequency-shifted to create a hologram beating at low frequency. Tens of particles, down to diameters of 10 nm, can be localised simultaneously and selectively in three dimensions with near- diffraction resolution by a numerical reconstruction of a single hologram acquired in 5 s.
Absil
E
E
Ecole Supérieure de Physique et de Chimie Industrielles ParisTech, Institut Langevin CNRS UMR 7587 and LPEM CNRS UPR A0005, 10 rue Vauquelin, Paris Cedex 05, France.
Tessier
G
G
Gross
M
M
Atlan
M
M
Warnasooriya
N
N
Suck
S
S
Coppey-Moisan
M
M
Fournier
D
D
D006046:Gold / Q000737:chemistry*; D006696:Holography / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D010783:Photometry / Q000379:methods*; D012031:Refractometry / Q000379:methods*; D013817:Thermography / Q000379:methods*
D006046:Gold