Open AccessGraphene Metamaterials for Intense, Tunable, and Compact Extreme Ultraviolet and X‐Ray Sources
Author(s) -
Pizzi Andrea,
Rosolen Gilles,
Wong Liang Jie,
Ischebeck Rasmus,
Soljačić Marin,
Feurer Thomas,
Kaminer Ido
Publication year - 2020
Publication title -
advanced science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.388
H-Index - 100
ISSN - 2198-3844
DOI - 10.1002/advs.201901609
Subject(s) - metamaterial , plasmon , physics , electron , photon , graphene , optics , optoelectronics , radiation , extreme ultraviolet , cathode ray , wavelength , electromagnetic radiation , materials science , laser , quantum mechanics
The interaction of electrons with strong electromagnetic fields is fundamental to the ability to design high‐quality radiation sources. At the core of all such sources is a tradeoff between compactness and higher output radiation intensities. Conventional photonic devices are limited in size by their operating wavelength, which helps compactness at the cost of a small interaction area. Here, plasmonic modes supported by multilayer graphene metamaterials are shown to provide a larger interaction area with the electron beam, while also tapping into the extreme confinement of graphene plasmons to generate high‐frequency photons with relatively low‐energy electrons available from tabletop sources. For 5 MeV electrons, a metamaterial of 50 layers and length 50 µm, and a beam current of 1.7 µA, it is, for instance, possible to generate X‐rays of intensity 1.5 × 10 7 photons sr −1 s −1 1%BW, 580 times more than for a single‐layer design. The frequency of the driving laser dynamically tunes the photon emission spectrum. This work demonstrates a unique free‐electron light source, wherein the electron mean free path in a given material is longer than the device length, relaxing the requirements of complex electron beam systems and potentially paving the way to high‐yield, compact, and tunable X‐ray sources.