Ferntosecond pulse coupling to near-field cantilevered probes

A novel nanoprobe for space- and time-resolved nonlinear optical spectroscopy has been developed. The nanoprobe is based on aperture-type SNOM using cantilevered sensors ("SNOM cantilevers"), capable to couple much higher power to the sample as compared to usual tapered fiber probes, along with negligible effect on femtosecond pulse duration, as directly assessed by second-order fringe-resolved autocorrelation in the near field. The use of such nanosource for pump-probe near-field spectroscopy promises to improve both time and space resolution with respect to the current state-of-the-art setups.