Holographic display

A holographic display comprising:

• a first light source configured to emit a first beam at a first time and a second beam at a second time;
• a first beam steerer including a first prism unit, the first prism unit including first electrodes and a first refraction surface disposed between the first electrodes;
• a second beam steerer disposed adjacent to the first beam steerer, the second beam steerer including a second prism unit, the second prism unit including second electrodes and a second refraction surface disposed between the second electrodes,
• wherein the first prism unit is configured to, in response to a voltage being applied between the first electrodes at the first time, receive the first beam emitted by the first light source, and allow the received first beam to pass through the first refraction surface at a right angle, and the second prism unit is configured to, in response to the voltage being applied between the second electrodes at the first time, allow the first beam passed through the first refraction surface at the right angle to pass through the second refraction surface at the right angle, and
• wherein the first prism unit is further configured to, in response to no voltage being applied between the first electrodes at the second time, receive the second beam emitted by the first light source, and primarily refract the received second beam, and the second prism unit is further configured to, in response to no voltage being applied between the second electrodes at the second time, secondarily refract the second beam primarily refracted by the first prism unit, to control a propagation direction of the emitted second beam to mimic light that is emitted from a virtual light source;
• an optical element configured to condense the first beam passed through the second refraction surface at the right angle, and condense the second beam secondarily refracted by the second prism unit;
• and
• a spatial light modulator configured to form a three-dimensional (3D) image by modulating the condensed first beam to focus on a first focal point, and modulating the condensed second beam to focus on a second focal point that is a virtual focal point,
• wherein the holographic display satisfies an equation:
• A/B=A′/B′,
• where A denotes a distance between the first light source and the spatial light modulator, B denotes a distance between the spatial light modulator and the first focal point, A′ denotes a distance between the first light source and the virtual light source, and B′ denotes a distance between the first focal point and the virtual focal point.