Science 381, 766

In most imaging techniques, the smallest feature sizes that can be resolved are on the order of the wavelength of light used for illumination. Several techniques have been developed that can resolve subwavelength features. Of these, superlenses fabricated from plasmonic materials and metamaterials suffer optical losses that limit their performance. Guan et al. show that illumination with synthetic frequency waves, waveforms that that are temporally attenuated, can retrieve subwavelength features, thus making their superlenses truly super. This work demonstrates a practical approach to overcoming intrinsic losses in plasmonic systems and shows that there is potential for substantial improvements in imaging and sensing capabilities. —Ian S. Osborne