title: Polarization-Insensitive Metalenses at Visible Wavelengths.
abstract: In this Letter, we demonstrate highly efficient, polarization-insensitive planar lenses (metalenses) at red, green, and blue wavelengths (λ = 660, 532, and 405 nm). Metalenses with numerical apertures (NA) of 0.85 and 0.6 and corresponding efficiencies as high as 60% and 90% are achieved. These metalenses are less than 600 nm-thick and can focus incident light down to diffraction-limited spots as small as ∼0.64λ and provide high-resolution imaging. In addition, the focal spots are very symmetric with high Strehl ratios. The single step lithography and compatibility with large-scale fabrication processes make metalenses highly promising for widespread applications in imaging and spectroscopy.
authors: Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University , Cambridge, Massachusetts 02138, United States.
authors: M
authors: M
authors: Khorasaninejad
authors: Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University , Cambridge, Massachusetts 02138, United States.
authors: A Y
authors: AY
authors: Zhu
authors: Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University , Cambridge, Massachusetts 02138, United States.|École Polytechnique , Palaiseau 91120, France.
authors: C
authors: C
authors: Roques-Carmes
authors: Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University , Cambridge, Massachusetts 02138, United States.
authors: W T
authors: WT
authors: Chen
authors: Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University , Cambridge, Massachusetts 02138, United States.|University of Waterloo , Waterloo, ON N2L 3G1, Canada.
authors: J
authors: J
authors: Oh
authors: Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University , Cambridge, Massachusetts 02138, United States.|University of Waterloo , Waterloo, ON N2L 3G1, Canada.
authors: I
authors: I
authors: Mishra
authors: Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University , Cambridge, Massachusetts 02138, United States.
authors: R C
authors: RC
authors: Devlin
authors: Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University , Cambridge, Massachusetts 02138, United States.
authors: F
authors: F
authors: Capasso
keywords: Metasurface; polarization-insensitive metalenses; titanium dioxide; visible wavelength