The disclosure provides a display device and a holographic display apparatus. The display device includes a display panel including a first linear polarizer located on a light-emitting side, so that the display panel emits linearly polarized image light; and a phase modulation panel disposed on the light-emitting side of the display panel and configured to perform phase modulation on the linearly polarized image light. The holographic display apparatus includes the display device.

Provided is a hologram image normalization method for a holographic printer. In a holographic printing method according to an embodiment, generating, encoding, and normalizing for the (n+1)-th hogel are performed in parallel with loading and recording of a normalized hologram for the n-th hogel, and moving and waiting for the (n+1)-th hogel. Accordingly, a global maximum value and a global minimum value for normalization may be calculated as approximate estimation values, and a hologram generation process and a printing process may be performed in parallel, so that a total printing time may be minimized and memory usage may be optimized when holographic printing is performed.

A metasurface structure including an array of sub-wavelength structures including a phase change material (PCM), encoded with different holographic images based on different phases of the PCM, the different phases including a first phase and a second phase. Phase transition between the first phase and the second phase occurs when the metasurface structure is thermally tuned. Each sub-wavelength structure in the array has a distinctive phase difference between the first phase and the second phase of the PCM.

An illumination system is arranged to output a light beam for illuminating a scene. The system comprises a spatial light modulator arranged to receive incident light, and to output light comprising a first component and a second component. The first component comprises incident light that is output without modulation by the spatial light modulator. The second component comprises incident light that is spatially-modulated according to a hologram and output by the spatial light modulator. A control device is operable to control the proportion of light output by the spatial light modulator that corresponds to the second component.

A display panel (1) comprising a body of optical material, the body having at least one optical image recorded therein in an encoded manner, wherein the image is selectively reconstructable and viewable (5, 6, 7) by illuminating the panel (1) using at least one light source (3a, 3b, 3c) under selected illumination conditions, wherein the image is reconstructable and viewable (5, 6, 7) such that at least one first optical property or parameter of the reconstructed image (e.g. its geometry, position in space, colour, its dynamic appearance) is selectable in value from amongst variable values of the at least one first optical property or parameter, or whose value is actively modifiable over time, as a function of or in dependence on the value of at least one second optical property or parameter of the illumination conditions of the at least one light source (e.g. its/their position(s) or spacing(s) relative to the panel (1), its/their colour, brightness/optical intensity, polarisation, direction of light ray propagation, application of a scanning technique to illuminate the panel (1)) which is selectable from amongst variable values thereof or which is actively modifiable in value over time.

An embodiment of the present disclosure provides a holographic optical element and a manufacturing method of a holographic optical element including holographic gratings, the manufacturing method including: a step (a) of forming a photosensitive substrate by coating one surface of a substrate with a photosensitive resin; and a step (b) of recording the holographic gratings by irradiating each of one surface and the other surface of the photosensitive substrate with laser light, wherein in the step (a), the photosensitive resin is applied so that a height of a photosensitive resin coating layer varies along a predetermined direction.