Cathodoluminescence for nanophotonics

Cathodoluminescence (CL) imaging is a powerful method for studying optical phenomena at the nanoscale. The electron beam acts as a very pure local excitation source. The hyperspectral light-emission maps produced with cathodoluminescence illustrate the local density of electromagnetic states, a quantity that determines how well light couples to matter and vice versa. Furthermore, the directionality and polarization of emission can rigorously be measured with angle-resolved images, thus providing yet more insight into the optical properties of nanostructures.

This makes the technique highly relevant to the field of nanophotonics. It is applicable to metallic as well as dielectric and semiconductor nanostructures, including nanoparticles, nanowires, metamolecules, metasurfaces, and photonic crystals. These structures find applications in (bio)sensing, fluorescence enhancement, non-linear optics, low-threshold steam generation, LED’s, solar cells, integrated photonics, lasers and much more.