A metasurface unit cell for use in constructing a metasurface array is provided. The unit cell may include a ground plane layer comprising a first conductive material, and a phase change material layer operably coupled to the ground plane layer. The phase change material layer may include a phase change material configured to transition between an amorphous phase and a crystalline phase in response to a stimulus. The unit cell may further include a patterned element disposed adjacent to the phase change material layer and includes a second conductive material. In response to the phase change material transitioning from a first phase to a second phase, the metasurface unit cell may resonate to generate an electromagnetic signal having a defined wavelength. The first phase may be the amorphous phase or the crystalline phase and the second phase may be the other of the amorphous phase or the crystalline phase.

An optical metasurface which shifts resonant frequency in response to changing temperature. The optical metasurface includes a membrane printed in a pattern from materials with a high coefficient of thermal expansion (“CTE”). The optical metasurface can include a plurality of high CTE fibers/structures in a first direction and a plurality of low CTE fibers/structures in a second direction perpendicular to the first direction. Alternatively, the high CTE substrate can include a plurality of high CTE fibers/structures in only a first direction. The high CTE substrate can include a plurality of high CTE fibers and a plurality of low CTE fiber in a pattern which creates desired sensing domains. An array of nanostructures is formed on the high CTE substrate. The array of nanostructures is designed to resonate with light transmitted through or impinging upon the optical metasurface. The resonant frequency of the response can be tuned thermally.

A silicon on insulator (SOI) photonic device having a waveguide is provided that includes a mode overlap portion with a topology optimized structure situated below an electrode of the capacitance structure. The device can significantly change a refractive index in a volume of mode overlap depending upon the applied potential to the capacitor and allows for a π phase shift in a modest mode overlap volume. The topology optimized structure has a waveguide and substrate that are partitioned in three dimensions using an extruded projection design. The electrode is a transition metal di-chalcogenide monolayer sheet (2D TMD). The enhanced mode overlay from the topology optimized waveguide portion allows a large reduction in the length of the waveguide with the mode overlap to achieve the needed phase shift for a photonic device.

Gravitational Janus microparticle having, a center-of-mass, a center-of-volume, and a non-uniform density, wherein: the center-of-mass and the center-of-volume are distinct. When suspended in a fluid, the microparticle substantially aligns with either: i) the gravitational field; or ii) the direction of an acceleration, such that the Janus microparticle is in substantial rotation equilibrium. After perturbation from substantial rotational equilibrium, the Janus microparticle reversibly rotates to return to substantial rotational equilibrium. The gravitational Janus microparticle may comprise at least two portions, each having distinct physical and/or chemical characteristics, wherein at least one portion provides a detectable effect following rotation and alignment of the microparticle.

A security device that exhibits at least one dynamic response upon change of orientation of the security device with respect to gravity, wherein the security device includes a hollow capsule completely filled with a liquid and one or more microscopic elements. In addition, the dynamic response continues after cessation of the change of orientation with respect to gravity. The dynamic response includes a transition of the one or more microscopic elements from substantial mechanical equilibrium to non-equilibrium upon action of the change of orientation with respect to gravity and back to substantial mechanical equilibrium after cessation of the change of orientation with respect to gravity. During the dynamic response, the one or more microscopic elements undergo at least one of a rotational motion and a translational motion relative to the liquid.

The disclosed subject matter provides systems and methods for spatial and spectral modulation of light. An example system for modulating light can include a substrate and a plurality of meta units, coupled to the substrate and configured to spatially and spectrally modulate the light, wherein the plurality of meta units includes a perturbation and forms a perturbed lattice supporting a quasi-bound state in the continuum.

A fast optical switch can be fabricated/constructed, when vanadium dioxide (VO.sub.2) ultra thin-film or a cluster of vanadium dioxide particles (less than 0.5 microns in diameter) embedded in an ultra thin-film of a polymeric material or in a mesh of metal nanowires is activated by either an electrical pulse (a voltage pulse or a current pulse) or a light pulse just to induce rapid insulator-to-metal phase transition (IMT) in vanadium dioxide ultra thin-film or vanadium dioxide particles embedded in an ultra thin-film of a polymeric material or in a mesh of metal nanowires. The applications of such a fast optical switch for an on-Demand optical add-drop subsystem, integrating with or without a wavelength converter are also described.

Methods and devices are disclosed for implementing quantum information processing based on electron spins in semiconductor and transition metal compositions. The transition metal electron orbitals split under semiconductor crystal field. The electron ground states are used as qubits. The transitions between the ground states involve electron spin flip. The semiconductor and transition metal compositions may be further included in optical cavities to facilitate quantum information processing. Quantum logic operations may be performed using single color or two color coherent resonant optical excitations via an excited electron state.

Alloys of GeSbSeTe (GSST) can be used to make actively tunable infrared transmission filters that are small, fast, and solid-state. These filters can be used for hyperspectral imaging, 3D LIDAR, portable bio/chem sensing systems, thermal emission control, and tunable filters. GSST is a low-loss phase-change material that can switch from a low-index (n=3), amorphous state to a high-index (n=4.5), hexagonal state with low loss (k<0.3) over a wavelength range of 2-10 microns or more. The GSST thickness can be selected to provide pure phase modulation, pure amplitude modulation, or coupled phase and amplitude modulation. GSST can be switched thermally in an oven, optically with visible light, or electrically via Joule heating at speeds from kilohertz to Gigahertz. It operates with reversible and polarization independent transmission switching over a wide incident angle (e.g., 0-60 degrees).

A spatial light modulator cell and arrays of spatial light modulator cells are disclosed. The spatial light modulator cells can comprise a phase change material (PCM) having a first side and a second side; an optical reflector configured to reflect an optical beam passing from the first side to the second side; and a PCM heater thermal conductively coupled to the PCM, wherein thermal modulation of the PCM modulates a phase of the PCM which varies light transmission through the PCM. Methods of making spatial light modulator cells and arrays are also disclosed.