Super-resolution label-free fieldoscopy with attosecond temporal resolution

We present a novel technique for broadband, label-free imaging that achieves sub-diffraction spatial resolution and attosecond temporal precision. Using the principle of Femtosecond Fieldoscopy, we generate 2D label-free images by exciting overtone and combination band vibrational modes of a sample in the 1.5 μm – 2.6 μm spectral range. While the conventional optical microscope at this range resolves features down to 2 μm, employing Fieldsocopy allows for the spatial resolution below the diffraction limit of the excitation pulse. Spatial resolution is evaluated using the point spread function (PSF) of 500nm polystyrene beads and a custom polymer-based resolution target with features from 200nm to 2 μm. We resolve a PSF below 600nm (FWHM) for the beads and clearly visualize spatial features on the resolution target down to 650 nm. This is the first demonstration of broadband, label-free super-resolution Fieldoscopy with attosecond temporal resolution.