Hyperspectral nanoscale imaging on dielectric substrates with coaxial optical antenna scan probes

An important goal in nano science is to unlock previously inaccessible physics and dynamics within nanoscale systems by combining the efficient nanoscale field confinement/optical resolution (∼10 nm) of optical antennae and the ultrafast temporal resolution (fs) inherent in optical studies with the capabilities of modern scanning probe techniques. Here we report on a significant step toward this goal using a novel nanofabricated coaxial antenna tip capable of recording useful Raman spectra in ∼50 ms to acquire 256 by 256 pixel images on dielectric substrates with a full spectrum at each pixel.