Single nanoparticle real and k-space spectroscopy with structured light

With the ever-increasing application range of nanoscale light–matter interactions, the study of individual nanostructures or particles becomes a crucial task. Over the last decade, it was proven that bespoke light fields tailored at the nanoscale can act as multi-purpose tools for the in-depth optical investigation at the single-particle level. Here we show that by tightly focusing cylindrical vector beams, a focal electromagnetic field landscape can be engineered, enabling the measurement of position-dependent resonance spectra. This method extends the existing nano-optics toolbox and can find a wide range of applications in spectroscopy.