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Alexander Y. Zhu
Researcher at Harvard University
Publications - 85
Citations - 9033
Alexander Y. Zhu is an academic researcher from Harvard University. The author has contributed to research in topics: Achromatic lens & Dispersion (optics). The author has an hindex of 30, co-authored 84 publications receiving 6313 citations. Previous affiliations of Alexander Y. Zhu include University of Pennsylvania & Agency for Science, Technology and Research.
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Journal ArticleDOI
Metalenses at visible wavelengths: Diffraction-limited focusing and subwavelength resolution imaging.
Mohammadreza Khorasaninejad,Wei Ting Chen,Robert C. Devlin,Jaewon Oh,Alexander Y. Zhu,Federico Capasso +5 more
TL;DR: The results firmly establish that metalenses can have widespread applications in laser-based microscopy, imaging, and spectroscopy, with image qualities comparable to a state-of-the-art commercial objective.
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A broadband achromatic metalens for focusing and imaging in the visible.
Wei Ting Chen,Alexander Y. Zhu,Vyshakh Sanjeev,Vyshakh Sanjeev,Mohammadreza Khorasaninejad,Zhujun Shi,Eric Lee,Eric Lee,Federico Capasso +8 more
TL;DR: It is shown that by judicious design of nanofins on a surface, it is possible to simultaneously control the phase, group delay and group delay dispersion of light, thereby achieving a transmissive achromatic metalens with large bandwidth.
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High-transmission dielectric metasurface with 2π phase control at visible wavelengths
Ye Feng Yu,Alexander Y. Zhu,Ramón Paniagua-Domínguez,Yuan Hsing Fu,Boris Luk'yanchuk,Arseniy I. Kuznetsov +5 more
TL;DR: In this paper, a uniform array of silicon nanodisks can exhibit close-to-unity transmission at resonance in the visible spectrum, and a single-layer gradient metasurface utilizing this concept is shown to achieve around 45% transmission into the desired order.
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Polarization-Insensitive Metalenses at Visible Wavelengths
Mohammadreza Khorasaninejad,Alexander Y. Zhu,Charles Roques-Carmes,Charles Roques-Carmes,Wei Ting Chen,Jaewon Oh,Jaewon Oh,Ishan Mishra,Ishan Mishra,Robert C. Devlin,Federico Capasso +10 more
TL;DR: 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, which makes them highly promising for widespread applications in imaging and spectroscopy.
Journal ArticleDOI
Achromatic Metalens over 60 nm Bandwidth in the Visible and Metalens with Reverse Chromatic Dispersion
Mohammadreza Khorasaninejad,Zhujun Shi,Alexander Y. Zhu,Wei Ting Chen,Vyshakh Sanjeev,Aun Zaidi,Federico Capasso +6 more
TL;DR: An achromatic metalens with a constant focal length over 60 nm bandwidth (λ= 490 nm to 550 nm) and metalenses with reverse chromatic dispersion, opposite of a Fresnel lens are demonstrated.