California Institute of Technology

Samsung Electronics Co., Ltd.

Ghazaleh Kafaie Shirmanesh

Harry A Atwater

Ruzan Sokhoyan

Duhyun Lee

Ragip Pala

Yu-Jung Lu

Pin Chieh Wu

Chanwook Baik

Chan-Wook Baik

Muhammad Alam

Rebecca D Glaudell

Kelly W Mauser

Yonghwi Kim

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.

Electrically tunable metasurfaces incorporating a phase change material

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.

Quantum dot light modulator and apparatus including the same

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.

Light modulation element, optical device including the light modulation element, and electronic device including the optical device

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.

Light emission device including output coupler and optical apparatus adopting the same

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.

Optical modulating device and apparatus including the same

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.

Active metasurfaces for dynamic polarization conversion

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.

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Pasadena, CA, United States of America

Ghazaleh Kafaie Shirmanesh