Optical device and optical system including the same
An optical device and an optical system including the optical device are provided. The optical device may include a reflective layer and a plurality of nano-beams spaced apart from the reflective layer. The plurality of nano-beams may be formed as a metasurface. The nano-beams may have a pattern structure having a plurality of metasurface forms, and the distance of the gaps between the plurality of nano-beams and the reflective layer may be adjustable individually or as a whole. The optical device may be a beam steering device or an optical phase modulator.
1. An optical device comprising:
a reflective layer; and
a plurality of nano-beams spaced apart from the reflective layer, the plurality of nano-beams being formed as a metasurface,
wherein a distance of a gap between the reflective layer and each of the plurality of nano-beams is adjustable.
2. The optical device of claim 1 , wherein the reflective layer and each of the plurality of nano-beams are spaced apart from each other and maintained in a non-contact state with respect to each other.
3. The optical device of claim 2 , wherein the plurality of nano-beams comprise a first nano-beam and a second nano-beam, and
wherein a first gap between the first nano-beam and the reflective layer is equal in distance to a second gap between the second nano-beam and the reflective layer.
4. The optical device of claim 3 , wherein the optical device is an optical phase modulator in which one of an amplitude and a phase of a beam incident from an external light source is modulated.
5. The optical device of claim 2 , wherein the plurality of nano-beams comprise a first nano-beam and a second nano-beam, and
wherein a first gap between the first nano-beam and the reflective layer is different in distance from a second gap between the second nano-beam and the reflective layer.
6. The optical device of claim 5 , wherein the optical device is a beam steering device.
7. The optical device of claim 1 , wherein the reflective layer is disposed on a substrate and the optical device further comprises a dielectric layer disposed on the reflective layer, and
wherein each of the plurality of nano-beams is spaced apart from the dielectric layer and a distance of a gap between the dielectric layer and each of the plurality of nano-beams is adjustable.
8. The optical device of claim 7 , wherein a thickness of the dielectric layer ranges from several nanometers to several tens of nanometers.
9. The optical device of claim 1 , further comprising:
a bottom contact layer disposed on a substrate;
a spacer layer disposed on the bottom contact layer; and
a dielectric layer disposed on the reflective layer, the reflective layer being disposed on the spacer layer,
wherein each of the plurality of nano-beams is spaced apart from the dielectric layer and a distance of a gap between the dielectric layer and each of the plurality of nano-beams is adjustable.
10. An optical system comprising:
an optical device comprising:
a reflective layer, and
a plurality of nano-beams spaced apart from the reflective layer, the plurality of nano-beams being formed as a metasurface, wherein a distance of a gap between the reflective layer and each of the plurality of nano-beams is adjustable;
a light source configured to irradiate light to the optical device;
a detector configured to detect at least one of a modulated beam and a steered beam from the optical device; and
a driving circuit configured to control at least one of the optical device and the detector.