Abstract: A process for fabricating a light detector with one or more antireflection (AR) and/or bandpass filter coatings deposited thereon by area-selective atomic layer deposition (ALD). The AR coatings may comprise a metal oxide or a metal fluoride, such as AlF3, Al2O3, and/or HfO2, and the bandpass filter coatings may comprise solar-blind bandpass filter coatings. The AR and/or bandpass filter coatings may be deposited with different thicknesses on different portions of the light detector using an intentional and controllable patterning by a lithography-based process. As a result, the AR and/or bandpass filter coatings provide a butcher-block style response profile with each of the different portions of the light detector targeting a specific bandpass of light. The AR and/or bandpass filter coatings comprise a linear variable filter (LVF) that provides a spatially varying response by the light detector.

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: A light modulation element according to example embodiments includes a substrate; a first lower DBR layer on the substrate including a first material layer alternately stacked with a second material layer having a different refractive index from the first material layer; a second lower DBR layer on the first lower DBR layer with a surface area less than the first lower DBR layer and including a third material layer alternately stacked with a fourth material layer having a different refractive index from the third material layer; an active layer on the second lower DBR layer, including a semiconductor material having a multi-quantum well structure and having a refractive index that varies according to an applied voltage; and an upper DBR layer on the active layer including a fifth material layer alternately stacked with a sixth material layer having a different refractive index from the fifth material 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: A light modulation element according to example embodiments includes a substrate; a first lower DBR layer on the substrate including a first material layer alternately stacked with a second material layer having a different refractive index from the first material layer; a second lower DBR layer on the first lower DBR layer with a surface area less than the first lower DBR layer and including a third material layer alternately stacked with a fourth material layer having a different refractive index from the third material layer; an active layer on the second lower DBR layer, including a semiconductor material having a multi-quantum well structure and having a refractive index that varies according to an applied voltage; and an upper DBR layer on the active layer including a fifth material layer alternately stacked with a sixth material layer having a different refractive index from the fifth material layer.

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 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: 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: 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.