C4-O-01Super-resolution imaging based on nonlinearities of plasmonic scattering

Abstract

Last year, the Nobel Chemistry Award was given to three physicists working on the development of superresolution microscopy. During the last decade, the diffraction limit of resolution was beautifully overcome by manipulating the on/off switching of fluorophores, or by saturation of fluorescence emission, resulting in resolution below 100 nm. Nevertheless, fluorescence exhibits intrinsic photobleaching issue. Therefore, it will be more than desirable to develop superresolution imaging modality based on an alternative contrast agent without bleaching, such as scattering. It is known that plasmonic nanoparticles exhibit extraordinarily strong scattering due to surface plasmon resonance (SPR). To our knowledge, neither saturation, nor switching of scattering from SPR structures has been reported, but there are plenty of reports on saturable absorption of plasmonic nanoparticles embedded in dielectric matrix. Since scattering and absorption are related to the real and imaginary parts of electric susceptibility, respectively, we expect to find saturable scattering with plasmonic particles.