Holographic display apparatus and method for providing enhanced viewing zone

A holographic display apparatus with an enhanced viewing zone, comprising:

• a first image providing apparatus configured to modulate light of a first wavelength into a first light wave corresponding to a hologram, to perform a Fourier transform on the first light wave to generate a Fourier-transformed first light wave, to split the Fourier-transformed first light wave and to output the Fourier-transformed first light wave;
• a second image providing apparatus configured to modulate light of a second wavelength into a second light wave corresponding to a hologram, to perform a Fourier transform on the second light wave to generate a Fourier-transformed second light wave, to split the Fourier-transformed second light wave, and to output the Fourier-transformed second light wave;
• a third image providing apparatus configured to modulate light of a third wavelength into a third light wave corresponding to a hologram, to perform a Fourier transform on the third light wave to generate a Fourier-transformed third light wave, to split the Fourier-transformed third light wave, and to output the Fourier-transformed third light wave;
• and
• a beam combining unit configured to combine and output the Fourier-transformed first light wave output from the first image providing apparatus, the Fourier-transformed second light wave output from the second image providing apparatus, and the Fourier-transformed third light wave output from the third image providing apparatus,
• wherein the beam combining unit includes a trichroic prism, and
• each of the first image providing apparatus, the second image providing apparatus, and the third image providing apparatus includes:
• a spatial light modulator configured to modulate light emitted from a corresponding light source into a light wave corresponding to a hologram;
• an optical system configured to perform a Fourier transform on the light wave from the spatial light modulator to generate a Fourier-transformed light wave;
• and
• a beam splitting element configured to split the Fourier-transformed light wave propagated from the optical system to expand a viewing zone of the holographic display.