Electron tube, imaging device and electromagnetic wave detection device

An electron tube comprising:

• a housing sealed and including a window transmitting an electromagnetic wave;
• an electron emitter disposed in the housing and including a meta-surface, a first electrode, and a second electrode, the meta-surface arranged to emit an electron in response to incidence of the electromagnetic wave, the first electrode and the second electrode being spaced away from each other and respectively arranged to apply potentials different from each other to the meta-surface;
• and
• a holder disposed in the housing and holding the electron emitter, wherein
• the meta-surface includes a first conductive line electrically connected to the first electrode, and a second conductive line spaced away from the first conductive line and electrically connected to the second electrode,
• the first conductive line extends from the first electrode toward the second conductive line, and
• the second conductive line extends from the second electrode toward the first conductive line.