Abstract

Pump-probe spectroscopy is central for exploring ultrafast dynamics of fundamental excitations, collective modes, and energy transfer processes. Typically carried out using conventional diffraction-limited optics, pump-probe experiments inherently average over local chemical, compositional, and electronic inhomogeneities. To circumvent this deficiency we have introduced pump-probe broad-band-mid-infrared spectroscopy at ∼20 nm spatial resolution, far below the diffraction limit set by the ∼10 μm wavelength. [1–3]

© 2015 IEEE