An acousto-optic element array includes: acousto-optic elements each including an acousto-optic generator, a light supply, and a wave transducer; a gate driver that selects an acousto-optic element to be driven from among the acousto-optic elements; an electrical data driver that is connected to an electrical wire and transmits electrical data to an electro-optic modulator configured to control the acousto-optic generator of the selected acousto-optic element; and a wave data driver that is connected to a waveguide and transmits wave data to the wave transducer of the selected acousto-optic element.

A holographic display is comprised of space-multiplexed elemental modulators, each of which consists of a surface acoustic wave transducer atop an anisotropic waveguide. Each line of the overall display consists of a single anisotropic waveguide across the display's length with multiple surface acoustic wave transducers spaced along the waveguide length, although for larger displays, the waveguide may be divided into segments, each provided with separate illumination. Light that is undiffracted by a specific transducer is available for diffraction by subsequent transducers. Per transducer, guided-mode light is mode-converted to leaky-mode light, which propagates into the substrate away from the viewer before encountering a volume reflection grating and being reflected and steered towards the viewer. The display is transparent and all reflection volume gratings operate in the Bragg regime, thereby creating no dispersion of ambient light.

Provided are an acousto-optic element, an acousto-optic element array, and a display apparatus including the acousto-optic element array. The acousto-optic element includes: an acousto-optic modulator which includes an acousto-optic layer formed of an acousto-optic material; a light supplier which supplies light to the acousto-optic modulator in a first direction; a first sound-wave modulator which applies first elastic waves to the acousto-optic modulator in a second direction; and a second sound-wave modulator which applies second elastic waves to the acousto-optic modulator in a third direction. The light supplied from the light supplier to the acousto-optic modulator is deflected by diffraction caused by the first elastic waves applied from the first sound-wave modulator and diffraction caused by the second elastic waves applied from the second sound-wave modulator, and is output from the acousto-optic modulator through a front side of the acousto-optic modulator.