Using superoscillations from a nanostructured Pancharatnam-Berry-phase metasurface serving as a marker, and four different polarization states of an incident laser, a recent paper (Science 364, 771 (2019)) reported 1nm localization errors at 800nm vacuum wavelength. Here, we show experimentally (unpublished) that digital optical-image cross-correlation analysis can achieve localization errors of 0.09nm with 12.5ms time resolution for similar marker footprints. Our approach uses incoherent unpolarized white light rather than a laser for illumination and works even for bare sample surfaces. Using time-harmonic modulation and synchronized stroboscopic illumination, we have taken nanometric movies at frequencies around 100kHz (Nature Commun. 10, 3384 (2019)).
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