Acousto-optic element, acousto-optic element array, and display apparatus including the acousto-optic element
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.
1. An acousto-optic element comprising:
an acousto-optic modulator which comprises 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,
wherein 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,
wherein the light supplier is disposed at a first side of the acousto-optic modulator, the first sound-wave modulator is disposed at a second side of the acousto-optic modulator, and the second sound-wave modulator is disposed at a third side of the acousto-optic modulator, and
the first to third sides of the acousto-optic modulator are different from the front side of the acousto-optic modulator.
2. The acousto-optic element of claim 1 , wherein the acousto-optic material comprises at least one of ZnO, LiNbO 3 , LiTaO 3 , quartz, TiO 2 , Si, SiN, AN, SiO 2 , and SrTiO 3 .
3. The acousto-optic element of claim 1 , wherein the acousto-optic modulator comprises:
a core layer which receives light;
a first cladding layer disposed under the core layer and having a refractive index which is different from a refractive index of the core layer; and
a second cladding layer disposed above the core layer and having a refractive index which is different from the refractive index of the core layer.
4. The acousto-optic element of claim 3 , wherein the refractive index of the core layer is greater than the refractive index of each of the first cladding layer and the second cladding layer.
5. The acousto-optic element of claim 4 , wherein at least one of the first cladding layer and the second cladding layer is an air layer.
6. The acousto-optic element of claim 3 , wherein the acousto-optic layer is at least one of the core layer, the first cladding layer, and the second cladding layer.
7. The acousto-optic element of claim 3 , wherein the core layer comprises a periodic photonic crystal structure in which a plurality of unit cells comprising a pattern are repeated.
8. The acousto-optic element of claim 7 , wherein the periodic photonic crystal structure of the core layer is a periodic structure in which at least two materials having different dielectric constants are periodically arranged in a 2-dimensional or 3-dimensional manner.
9. The acousto-optic element of claim 7 , wherein the first cladding layer and the second cladding layer comprise a same periodic photonic crystal structure as the periodic photonic crystal structure of the core layer.
10. The acousto-optic element of claim 7 , wherein the periodic photonic crystal structure of the core layer emits the light that is represented by an equifrequency contour of a plurality of optical wave vectors which is flat in the first direction and the second direction.
11. The acousto-optic element of claim 3 , wherein the acousto-optic modulator further comprises a reflection layer under the first cladding layer.
12. The acousto-optic element of claim 11 , wherein the acousto-optic modulator further comprises a substrate under the reflection layer.
13. The acousto-optic element of claim 12 , wherein the acousto-optic layer is at least one of the core layer, the first cladding layer, the second cladding layer, the reflection layer, and the substrate.
14. The acousto-optic element of claim 12 , wherein at least one of the core layer, the first cladding layer, the second cladding layer, the reflection layer, and the substrate is formed of a piezoelectric material which is used as a sound wave generator of at least one of the first sound-wave modulator and the second sound-wave modulator.
15. The acousto-optic element of claim 14 , wherein the piezoelectric material comprises at least one of ZnO, PZT, LiNbO 3 , LiTaO 3 , quartz, and SrTiO 3 .
16. The acousto-optic element of claim 13 , wherein a first sound wave generator of the first sound-wave modulator and a second sound wave generator of the second sound-wave modulator are formed in different layers.
17. The acousto-optic element of claim 1 , wherein the first to third sides are different sides of the acousto-optic modulator.
18. The acousto-optic element of claim 1 , wherein the light supplier comprises:
an optical waveguide disposed at the first side of the acousto-optic modulator; and
an optical coupler disposed between the optical waveguide and the acousto-optic modulator.
19. The acousto-optic element of claim 18 , wherein the optical coupler is a grating coupler.
20. The acousto-optic element of claim 17 , wherein the first sound-wave modulator comprises:
a first sound wave generator disposed at the second side of the acousto-optic modulator; and
a first high-frequency waveguide through which first high-frequency power is applied to the first sound wave generator,
wherein the second sound-wave modulator comprises:
a second sound wave generator disposed at the third side of the acousto-optic modulator; and
a second high-frequency waveguide through which second high-frequency power is applied to the second sound wave generator.
21. The acousto-optic element of claim 20 , wherein the first sound wave generator and the second sound wave generator are formed in different layers.
22. The acousto-optic element of claim 20 , wherein the first high-frequency waveguide and the second high-frequency waveguide are formed in different layers.
23. The acousto-optic element of claim 20 , wherein the first high-frequency power of the first high-frequency waveguide, and the second high-frequency power of the second high-frequency waveguide are respectively adjusted in frequency and phase and intensity according to the frequency, such that a shape, direction, and intensity of the light output is controlled from the acousto-optic modulator through the front side of the acousto-optic modulator.
24. The acousto-optic element of claim 1 , wherein a plurality of sound absorbing members are disposed outside the first sound-wave modulator and the second sound-wave modulator, respectively.