Super-Resolution Structured Pump-Probe Microscopy

Imaging excited-state dynamics in complex materials provides an important avenue for understanding the role played by micro- and nanoscale structural and compositional heterogeneity in the performance of active electronic and optoelectronic devices. Here, we develop structured pump probe microscopy (SPPM), a subdiffraction-limited, time-resolved microscopy that incorporates a focused diffraction-limited probe field together with a spatially modulated pump excitation field. We apply the technique to study free carrier dynamics in silicon nanowires, demonstrating far-field ultrafast time-resolved spectroscopy with a 114 nm point-spread function while remaining in the perturbative excitation regime. We predict SPPM will provide an accessible approach subwavelength regions in complex materials systems.