Spatial light modulator and holographic three-dimensional display device

A holographic three-dimensional device, comprising:

• a light source module configured to emit coherent light in a timed manner;
• a beam expansion and collimation module located on a light exiting side of the light source module and configured to expand and collimate light emitted from the light source module;
• a spatial light modulator located on a side of the beam expansion and collimation module facing away from the light source module;
• a field lens module located on a side of the spatial light modulator away from the light source module;
• and
• a liquid crystal grating module configured to bend light emitted from the field lens module in a positive and/or negative direction of a second reference direction,
• wherein the spatial light modulator includes:
• a first liquid crystal panel configured to adjust a phase of first light and including a first liquid crystal layer;
• a second liquid crystal panel configured to adjust an amplitude of the first light, located on one side of the first liquid crystal panel, and including a second liquid crystal layer including second liquid crystal molecules having a liquid crystal optical axis;
• a quarter-wave plate located on a side of the second liquid crystal panel facing away from the first liquid crystal panel;
• and
• a polarizer located on a side of the quarter-wave plate facing away from the first liquid crystal panel,
• wherein the second liquid crystal panel includes a first optical axis direction, a difference between a refractive index of the second liquid crystal molecules along a direction of the liquid crystal optical axis and a refractive index perpendicular to the direction of the liquid crystal optical axis is Δn, a thickness of the second liquid crystal layer is d, the wavelength of the first light is λ1, and 0.5λ1≤Δn×d≤0.75λ1, and
• wherein:
• the first liquid crystal panel further includes a first alignment film with a first alignment direction and a second alignment film with a second alignment direction;
• the first alignment film and the second alignment film are respectively located on two sides of the first liquid crystal panel;
• the second alignment direction is parallel to a first reference direction;
• an angle between an optical axis direction of the quarter-wave plate and the second alignment direction is approximately 30°;
• and
• an angle between a polarization direction of the polarizer and the second alignment direction is approximately 15°.