Our experimental demonstration of super-achromatic diffractive lenses (i.e., flat lenses that are corrected for more than 4 wavelengths) was recently published (freely available here). This is an important paper that demonstrates that diffractive optics can indeed be used for broadband focusing, when appropriately designed. Most people in the past assumed that this wasn’t possible with high efficiency. Resorting to meta-lenses for super-achromatic focusing is not necessary. Congratulations to Peng and Nabil for this achievement!