Observation of the reversed Cherenkov radiation.
Reversed Cherenkov radiation is the exotic electromagnetic radiation that is emitted in the opposite direction of moving charged particles in a left-handed material. Reversed Cherenkov radiation has not previously been observed, mainly due to the absence of both suitable all-metal left-handed materials for beam transport and suitable couplers for extracting the reversed Cherenkov radiation signal. In this paper, we develop an all-metal metamaterial, consisting of a square waveguide loaded with complementary electric split ring resonators. We demonstrate that this metamaterial exhibits a left-handed behaviour, and we directly observe the Cherenkov radiation emitted predominantly near the opposite direction to the movement of a single sheet electron beam bunch in the experiment. These observations confirm the reversed behaviour of Cherenkov radiation. The reversed Cherenkov radiation has many possible applications, such as novel vacuum electronic devices, particle detectors, accelerators and new types of plasmonic couplers.
National Key Laboratory of Science and Technology on Vacuum Electronics in Chengdu, Institute of High Energy Electronics, School of Physical Electronics, University of Electronic Science and Technology of China, No. 4, Section 2, North Jianshe Road, Chengdu 610054, China.
Zhaoyun
Z
Duan
National Key Laboratory of Science and Technology on Vacuum Electronics in Chengdu, Institute of High Energy Electronics, School of Physical Electronics, University of Electronic Science and Technology of China, No. 4, Section 2, North Jianshe Road, Chengdu 610054, China.
Xianfeng
X
Tang
National Key Laboratory of Science and Technology on Vacuum Electronics in Chengdu, Institute of High Energy Electronics, School of Physical Electronics, University of Electronic Science and Technology of China, No. 4, Section 2, North Jianshe Road, Chengdu 610054, China.
Zhanliang
Z
Wang
National Key Laboratory of Science and Technology on Vacuum Electronics in Chengdu, Institute of High Energy Electronics, School of Physical Electronics, University of Electronic Science and Technology of China, No. 4, Section 2, North Jianshe Road, Chengdu 610054, China.
Yabin
Y
Zhang
National Key Laboratory of Science and Technology on Vacuum Electronics in Chengdu, Institute of High Energy Electronics, School of Physical Electronics, University of Electronic Science and Technology of China, No. 4, Section 2, North Jianshe Road, Chengdu 610054, China.|School of Electronic Engineering and Computer Science, Queen Mary, University of London, London E1 4NS, UK.
Xiaodong
X
Chen
Department of Physics, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
Min
M
Chen
National Key Laboratory of Science and Technology on Vacuum Electronics in Chengdu, Institute of High Energy Electronics, School of Physical Electronics, University of Electronic Science and Technology of China, No. 4, Section 2, North Jianshe Road, Chengdu 610054, China.
Yubin
Y
Gong