Abstract: Electrically tunable metasurfaces including an array of subwavelength metasurface unit elements are presented. The unit elements include a stacked metal-insulator-metal structure within which an active phase change layer is included. A purely insulator, metal, or coexisting metal-insulator phase of the active layer can be electrically controlled to tune an amplitude and phase response of the metasurfaces. In combination with the subwavelengths dimensions of the unit elements, the phase and amplitude response can be controlled in a range from optical wavelengths to millimeter wavelength of incident light. Electrical control of the unit elements can be provided via resistive heating produced by flow of current though a top metal layer of the unit elements. Alternatively, electrical control of the unit elements can be provided via electrical field effect produced by applying a voltage differential between the top and bottom metal layers of the unit elements.

Abstract: Provided is a quantum dot (QD) light modulator and an apparatus including the QD light modulator. The QD light modulator may include a QD-containing layer including QDs having light-emission characteristics, a refractive index change layer arranged adjacent to the QD-containing layer, and a reflector arranged facing the QD-containing layer. The refractive index change layer may include a carrier density change area in which a carrier density changes, and the carrier density change area may be arranged adjacent to the QD-containing layer. The light-emission characteristics of the QD-containing layer may be modulated according to a change in a property of the refractive index change layer. The QD light modulator may further include a nano-antenna structure arranged on the QD-containing layer.

Abstract: Provided are light emission devices including an output coupler and optical apparatuses having the same. The light emission device may include a QD layer containing quantum dots and a nano-antenna structure including an output coupler configured to control an output characteristic of light emitted from the QD layer. The output coupler may be configured to output an emission wavelength of the QD layer. The nano-antenna structure may include one of a metallic antenna, a dielectric antenna, and a slit-containing structure, or may have a multi-patch antenna structure or a fishbone antenna structure.

Abstract: An optical modulating device may include a plurality of quantum dot (QD)-containing layers having QDs and a plurality of refractive index change layers. The QD-containing layers may be disposed between the refractive index change layers, respectively. The optical modulating device may be configured to modulate light-emission characteristics of the plurality of QD-containing layers. At least two of the QD-containing layers may have different central emission wavelengths. At least two of the plurality of refractive index change layers may include different materials or have different carrier densities.

Abstract: The optical response of a metasurface is controlled by actuating it via an electrical or magnetic field, temperature control, optical pumping or electromechanical actuation. The metasurface will therefore control the polarization of the incident light. The metasurface comprises an array of patch antennas. The patch antennas are in the form of asymmetrical elements, including rotated rods, cross-shapes, V-shapes, and L-shapes.

Abstract: Electrically tunable metasurfaces including an array of subwavelength metasurface unit elements are presented. The unit elements include a stacked metal-insulator-metal structure within which an active phase change layer is included. A purely insulator, metal, or coexisting metal-insulator phase of the active layer can be electrically controlled to tune an amplitude and phase response of the metasurfaces. In combination with the subwavelengths dimensions of the unit elements, the phase and amplitude response can be controlled in a range from optical wavelengths to millimeter wavelength of incident light. Electrical control of the unit elements can be provided via resistive heating produced by flow of current though a top metal layer of the unit elements. Alternatively, electrical control of the unit elements can be provided via electrical field effect produced by applying a voltage differential between the top and bottom metal layers of the unit elements.

Abstract: An optical modulating device includes a permittivity change layer having a variable permittivity, a dielectric layer disposed on the permittivity change layer, a nanoantenna disposed on the dielectric layer, and a light-emitting structure disposed adjacent to the permittivity change layer.

Abstract: An array of unit cells allows beam steering of an incident electromagnetic wave. Each unit cell has a back reflector, a conductive oxide between gate dielectrics, and an antenna. Voltage bias applied to different layers enables the accumulation or depletion of charges at the top and bottom interfaces of the conductive oxide. The charge accumulation and depletion regions control the refractive index of the material, enabling control of the reflected electromagnetic wave.

Abstract: An optical modulating device may include a plurality of quantum dot (QD)-containing layers having QDs and a plurality of refractive index change layers. The QD-containing layers may be disposed between the refractive index change layers, respectively. The optical modulating device may be configured to modulate light-emission characteristics of the plurality of QD-containing layers. At least two of the QD-containing layers may have different central emission wavelengths. At least two of the plurality of refractive index change layers may include different materials or have different carrier densities.

Abstract: Provided are light emission devices including an output coupler and optical apparatuses having the same. The light emission device may include a QD layer containing quantum dots and a nano-antenna structure including an output coupler configured to control an output characteristic of light emitted from the QD layer. The output coupler may be configured to output an emission wavelength of the QD layer. The nano-antenna structure may include one of a metallic antenna, a dielectric antenna, and a slit-containing structure, or may have a multi-patch antenna structure or a fishbone antenna structure.

Abstract: Provided is a quantum dot (QD) light modulator and an apparatus including the QD light modulator. The QD light modulator may include a QD-containing layer including QDs having light-emission characteristics, a refractive index change layer arranged adjacent to the QD-containing layer, and a reflector arranged facing the QD-containing layer. The refractive index change layer may include a carrier density change area in which a carrier density changes, and the carrier density change area may be arranged adjacent to the QD-containing layer. The light-emission characteristics of the QD-containing layer may be modulated according to a change in a property of the refractive index change layer. The QD light modulator may further include a nano-antenna structure arranged on the QD-containing layer.

Abstract: The optical response of a metasurface is controlled by actuating it via an electrical or magnetic field, temperature control, optical pumping or electromechanical actuation. The metasurface will therefore control the polarization of the incident light. The metasurface comprises an array of patch antennas. The patch antennas are in the form of asymmetrical elements, including rotated rods, cross-shapes, V-shapes, and L-shapes.

Abstract: An array of unit cells allows beam steering of an incident electromagnetic wave. Each unit cell has a back reflector, a conductive oxide between gate dielectrics, and an antenna. Voltage bias applied to different layers enables the accumulation or depletion of charges at the top and bottom interfaces of the conductive oxide. The charge accumulation and depletion regions control the refractive index of the material, enabling control of the reflected electromagnetic wave.

Abstract: An optical modulating device includes a permittivity change layer having a variable permittivity, a dielectric layer disposed on the permittivity change layer, a nanoantenna disposed on the dielectric layer, and a light-emitting structure disposed adjacent to the permittivity change layer.

Abstract: An optical modulating device includes a permittivity change layer having a variable permittivity, a dielectric layer disposed on the permittivity change layer, a nanoantenna disposed on the dielectric layer, and a light-emitting structure disposed adjacent to the permittivity change layer.

Abstract: An optical modulating device includes a permittivity change layer having a variable permittivity, a dielectric layer disposed on the permittivity change layer, a nanoantenna disposed on the dielectric layer, and a light-emitting structure disposed adjacent to the permittivity change layer.