The invention relates to a photocathode including an input window (210) suitable for receiving a flow of incident photons, and an active layer (230), the active layer consisting of a plurality of elementary layers (2301, 2302) made of semiconductor materials having decreasing forbidden bandwidths in the direction of the flow of incident photons. The surface of the photocathode opposite the input window is structured so that each elementary layer of the active layer has its own photoelectric emission surface (2401, 2402). By choosing the semiconductor materials of the elementary layers, it is possible to obtain an image which has high sensitivity in both the visible spectrum and the near infrared.

Exemplary metamaterial photocathodes enable detection of light from visible through long wave infrared wavelengths. Metamaterial stacks, comprising gold, silicon, and cesium-oxide, coupled to a semiconductor allow hot electrons to efficiently enter a vacuum. The hot electrons are multiplied in a multichannel plate and directly through another vacuum towards a phosphorus screen.

Exemplary metamaterial photocathodes enable detection of light from visible through long wave infrared wavelengths. Metamaterial stacks, comprising gold, silicon, and cesium-oxide, coupled to a semiconductor allow hot electrons to efficiently enter a vacuum. The hot electrons are multiplied in a multichannel plate and directly through another vacuum towards a phosphorus screen.

Exemplary metamaterial photocathodes enable detection of light from visible through long wave infrared wavelengths. Metamaterial stacks, comprising gold, silicon, and cesium-oxide, coupled to a semiconductor allow hot electrons to efficiently enter a vacuum. The hot electrons are multiplied in a multichannel plate and directly through another vacuum towards a phosphorus screen.

Exemplary metamaterial photocathodes enable detection of light from visible through long wave infrared wavelengths. Metamaterial stacks, comprising gold, silicon, and cesium-oxide, coupled to a semiconductor allow hot electrons to efficiently enter a vacuum. The hot electrons are multiplied in a multichannel plate and directly through another vacuum towards a phosphorus screen.

A photoelectric conversion device is provided with an electron emitter including a meta-surface emitting an electron in response to incidence of an electromagnetic wave. The meta-surface includes a plurality of photoelectric conversion units having a sensitivity for electromagnetic waves having mutually different wavelength regions. The plurality of photoelectric conversion units respectively include patterns having mutually different configurations.

In one embodiment, the present disclosure provides a target or mold having one or more support arms coupled to a substrate. The support arm can be used in handling or positioning a target, In another embodiment, the present disclosure provides target molds, targets produced using such molds, and a method for producing the targets and molds. In various implementations, the targets are formed in a number of disclosed shapes, including a funnel cone, a funnel cone having an extended neck, those having Gaussian-profile, a cup, a target having embedded metal slugs, metal dotted foils, wedges, metal stacks, a Winston collector having a hemispherical apex, and a Winston collector having an apex aperture. In yet another embodiment, the present disclosure provides a target mounting and alignment system.

In one embodiment, the present disclosure provides a target or mold having one or more support arms coupled to a substrate. The support arm can be used in handling or positioning a target, In another embodiment, the present disclosure provides target molds, targets produced using such molds, and a method for producing the targets and molds. In various implementations, the targets are formed in a number of disclosed shapes, including a funnel cone, a funnel cone having an extended neck, those having Gaussian-profile, a cup, a target having embedded metal slugs, metal dotted foils, wedges, metal stacks, a Winston collector having a hemispherical apex, and a Winston collector having an apex aperture. In yet another embodiment, the present disclosure provides a target mounting and alignment system.

A radiation sensor device is disclosed for use with a radiation source, capable of emitting radiation with photon energies larger than the work function of the target comprising a target plate to be impacted by the radiation to generate photo-electrons, the target plate being electrically isolated from a shielding electrode. The shielding electrode is arranged to collect energy-filtered photo-electrons from the target plate, using an electrostatic barrier for the filtering. The target plate is constructed of a carbon material. A current measurement device is operative to keep the target plate at a preset voltage difference with respect to the shielding electrode and measure a photo-electron deficit current as a result of radiation impact on the target plate.

A radiation sensor device is disclosed for use with a radiation source, capable of emitting radiation with photon energies larger than the work function of the target comprising a target plate to be impacted by the radiation to generate photo-electrons, the target plate being electrically isolated from a shielding electrode. The shielding electrode is arranged to collect energy-filtered photo-electrons from the target plate, using an electrostatic barrier for the filtering. The target plate is constructed of a carbon material. A current measurement device is operative to keep the target plate at a preset voltage difference with respect to the shielding electrode and measure a photo-electron deficit current as a result of radiation impact on the target plate.