Spatial light modulator, holographic three-dimensional image display including the same, and method for modulating spatial light

A holographic image display comprising:

• a writing optical system comprising a first light source that radiates writing light;
• a reproduction optical system comprising a second light source that radiates reproduction light;
• and
• an image display unit disposed between the writing optical system and the reproduction optical system, wherein the image display unit comprises a spatial light modulator that modulates a phase of light incident on a plurality of pixels and a light addressing unit that addresses light from the writing optical system to each pixel of the optical light modulator, wherein the spatial light modulator comprises:
• a variable refractive index layer having a refractive index which is variable based on one of an optical signal and an electrical signal,
• a metal layer that is disposed on an upper surface of the variable refractive index layer, wherein light incident on the metal layer causes the generation of a surface plasmon at an interface between the variable refractive index layer and the metal layer, and
• a high refractive index layer that is disposed on the metal layer, wherein a refractive index of the high refractive index layer is higher than a maximum refractive index of the variable refractive index layer,
• wherein a moving distance of the surface plasmon is smaller than a pitch of the plurality of pixels.

A method for modulating light, whereby a phase of light incident on a plurality of pixels is modulated, the method comprising:

• changing a refractive angle of light by radiating writing light onto a variable refractive index layer;
• generating a surface plasmon by radiating reproduction light onto a metal layer disposed on the variable refractive index layer;
• and
• changing a phase of light reflected from the variable refractive index layer via the surface plasmon.