Methods for using electron diffraction holography to investigate a sample, according to the present disclosure include the initial steps of emitting a plurality of electrons toward the sample, forming the plurality of electrons into a first electron beam and a second electron beam, and modifying the focal properties of at least one of the two beams such that the two beams have different focal planes. Once the two beams have different focal planes, the methods include focusing the first electron beam such that it has a focal plane at or near the sample, and focusing the second electron beam so that it is incident on the sample, and has a focal plane in the diffraction plane. An interference pattern of the first electron beam and the diffracted second electron beam is then detected in the diffraction plane, and then used to generate a diffraction holograph.

Various examples of out-of-plane multicolor waveguide holography systems, methods of manufacture, and methods of use are described herein. In some examples, a multicolor waveguide holography system includes a planar waveguide to convey optical radiation between a grating coupler and a metasurface hologram. The grating coupler may be configured to couple out-of-plane optical radiation of three different color incident at three different angles into the planar waveguide. The combined multicolor optical radiation may be conveyed by the waveguide to the metasurface hologram. The metasurface hologram may diffractively decouple the three colors of optical radiation for off-plane propagation to form a multicolor holographic image in free space.

A phase modulation structure includes a recording surface including phase angle recording regions in a plurality of calculated element regions corresponding to reconstruction points of an image on a one-to-one basis, each phase angle recording region being formed of a plurality of unit blocks in each of which a phase angle is recorded, the phase angle being calculated based on a phase that is a sum of a plurality of phases of light from the corresponding reconstruction points; and a representative area that is one of divisions of the calculated element region, the representative area being obtained by radially dividing the calculated element region centered on a point on the calculated element region, the point being obtained by extending a normal line from the corresponding reconstruction point to the calculated element region on the recording surface.

Various examples of out-of-plane multicolor waveguide holography systems, methods of manufacture, and methods of use are described herein. In some examples, a multicolor waveguide holography system includes a planar waveguide to convey optical radiation between a grating coupler and a metasurface hologram. The grating coupler may be configured to couple out-of-plane optical radiation of three different color incident at three different angles into the planar waveguide. The combined multicolor optical radiation may be conveyed by the waveguide to the metasurface hologram. The metasurface hologram may diffractively decouple the three colors of optical radiation for off-plane propagation to form a multicolor holographic image in free space.

An integrated three-dimensional display includes a recording surface which includes a calculated element region in which phase components of light from light converging points of a holographic reconstructed image are calculated, and a phase angle recorded area for recording a phase angle calculated based on the phase components. The phase angle recorded area includes a plurality of monochromatic regions having a uneven structure surface. The phase angle is recorded in an overlap area in which the calculated element region and the phase angle recorded area overlap each other. Light converges on the light converging points at specific distances from the recording surface, the specific distances being determined for the respective light converging points even when light reflected from the plurality of monochromatic regions converges.

The invention relates to a method for detecting a measured value (dϕ/dx, M). According to the invention, provision is made for a sinusoidal excitation signal (Ue) with a predetermined excitation frequency (f), with or without a superposed DC component (Uoffset), to be fed to an input of a component (100, C), for at least one electron holography measuring step to be carried out, in which an electron beam (Se) is directed on the component (100, C), said electron-beam penetrating and/or passing the component (100, C) and subsequently being superposed with a reference electron-beam (Sr), and for an electrical hologram (EHG) arising by interference of the two electron beams (Se, Sr) during a predetermined measurement window (F) to be measured and the phase image (PB) to be ascertained therefrom, and for the measured value (M) to be formed on the basis of the phase image (PB), wherein the temporal length (Tf) of the measurement window (F) of the electron holography measuring step is shorter than half the period (T) of the sinusoidal excitation signal (Uc).

Methods for using electron diffraction holography to investigate a sample, according to the present disclosure include the initial steps of emitting a plurality of electrons toward the sample, forming the plurality of electrons into a first electron beam and a second electron beam, and modifying the focal properties of at least one of the two beams such that the two beams have different focal planes. Once the two beams have different focal planes, the methods include focusing the first electron beam such that it has a focal plane at or near the sample, and focusing the second electron beam so that it is incident on the sample, and has a focal plane in the diffraction plane. An interference pattern of the first electron beam and the diffracted second electron beam is then detected in the diffraction plane, and then used to generate a diffraction holograph.

The present invention discloses a method that combines two different hologram origination processes in a single photoresist layer by using an interlayer to transfer structures exposed by electron beam lithography into overlapped with dot-matrix hologram areas, and fabricated holographic structures are replicated in multilayer polymer films. Dot-matrix technique is low cost process, which has high origination speed and can be used for the patterning of large areas of holograms with high diffraction efficiency. Electron beam lithography allows the formation of high resolution structures. The proposed manufacturing method allows combining these two technologies so that the final security device could contain electron beam patterned high resolution diffraction gratings, computer generated holograms, as well as dot-matrix laser patterned large hologram areas with high diffraction efficiency, providing an increased level of protection.

An integrated three-dimensional display includes a recording surface which includes a calculated element region in which phase components of light from light converging points of a holographic reconstructed image are calculated, and a phase angle recorded area for recording a phase angle calculated based on the phase components. The phase angle recorded area includes a plurality of monochromatic regions having a uneven structure surface. The phase angle is recorded in an overlap area in which the calculated element region and the phase angle recorded area overlap each other. Light converges on the light converging points at specific distances from the recording surface, the specific distances being determined for the respective light converging points even when light reflected from the plurality of monochromatic regions converges.

Methods for using electron diffraction holography to investigate a sample, according to the present disclosure include the initial steps of emitting a plurality of electrons toward the sample, forming the plurality of electrons into a first electron beam and a second electron beam, and modifying the focal properties of at least one of the two beams such that the two beams have different focal planes. Once the two beams have different focal planes, the methods include focusing the first electron beam such that it has a focal plane at or near the sample, and focusing the second electron beam so that it is incident on the sample, and has a focal plane in the diffraction plane. An interference pattern of the first electron beam and the diffracted second electron beam is then detected in the diffraction plane, and then used to generate a diffraction holograph.