@article { ISI:000396185800073,
	title = {Achromatic Metalens over 60 nm Bandwidth in the Visible and Metalens with Reverse Chromatic Dispersion},
	journal = {NANO LETTERS},
	volume = {17},
	number = {3},
	year = {2017},
	month = {MAR},
	pages = {1819-1824},
	publisher = {AMER CHEMICAL SOC},
	type = {Article},
	address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA},
	abstract = {In this Letter, we experimentally report an achromatic metalens (AML) operating over a continuous bandwidth in the visible. This is accomplished via dispersion engineering of dielectric phase shifters: titanium dioxide nanopillars tiled on a dielectric spacer layer above a metallic mirror. The AML works in reflection mode with a focal length independent of wavelength from lambda = 490 to 550 nm. We also design a metalens with reverse chromatic dispersion, where the focal length increases as the wavelength increases, contrary to conventional diffractive lenses. The ability to engineer the chromatic dispersion of metalenses at will enables a wide variety of applications that were not previously possible. In particular, for the AML design, we envision applications such as imaging under LED illumination, fluorescence, and photoluminescence spectroscopy.},
	keywords = {achromatic metalens, dispersion engineering visible spectrum, metasurface, titanium dioxide},
	issn = {1530-6984},
	doi = {10.1021/acs.nanolett.6b05137},
	author = {M. Khorasaninejad and Shi, Z. and A. Y. Zhu and W. T. Chen and V. Sanjeev and A. Zaidi and F. Capasso}
}
