Switches for electromagnetic radiation, including radiofrequency switches and optical switches, are provided. Also provided are methods of using the switches. The switches incorporate layers of high quality VO.sub.2 that are composed of a plurality of connected crystalline VO.sub.2 domains having the same crystal structure and orientation.

A reconfigurable polar molecule includes a symmetric nonpolar molecule portion having an elongated shape defined by a longitudinal axis and lateral axis, the longitudinal axis being longer than the lateral axis; a positive ionically charged group at a first end and a negative ionically charged group at a second end of the longitudinal axis, the positive and negative ionically charged groups forming a permanent dipole; a first bridging group and a second bridging group on opposing ends of the lateral axis, the first and second bridging groups being linear nonpolar groups; and a first support portion bonded to the first bridging group, and a second support portion bonded to the second bridging group, the first bridging group and the second bridging group being nonpolar and having structures that enable free rotation of the symmetric nonpolar molecule portion through the first bridging group and the second bridging group.

A fast optical switch can be fabricated/constructed, when a vanadium dioxide (VO.sub.2) and a two-dimensional (2-D) material is activated by either an electrical pulse (a voltage pulse or a current pulse) or a light pulse just to induce an insulator-to-metal phase transition (IMT) in vanadium dioxide. The applications of such a fast optical switch for an on-demand optical add-drop subsystem, integrating with (a) a light slowing/light stopping component (based on metamaterials and/or nanoplasmonic structures) and (b) with or without a wavelength converter are also described.

A fast optical switch can be fabricated/constructed, when a vanadium dioxide (VO.sub.2) and a two-dimensional (2-D) material is activated by either an electrical pulse (a voltage pulse or a current pulse) or a light pulse just to induce an insulator-to-metal phase transition (IMT) in vanadium dioxide. 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.

An object is to provide a phase difference compensation element capable of improving the contrast of a liquid crystal display device while solving the problems of a high cost, an increase in the lead time, an increase in the mounting space, and the durability. A phase difference compensation element includes: a phase difference imparting and reflection preventing layer; a first birefringence layer and a second birefringence layer in which an angle of a corner formed by a main axis of refractive index anisotropy and a surface of a transparent substrate is not 90 degrees; a third birefringence layer in which an angle of a corner formed by a main axis of refractive index anisotropy and the surface of the transparent substrate is 0 degrees, wherein, when segments acquired when the main axes of the first, second, and third birefringence layers are projected onto the transparent substrate are respectively denoted by a segment A, a segment B, and a segment C, relations of the following (1) and (2) are satisfied. (1) The angle of the corner formed by the segment A and the segment B is 45 degrees or more and 70 degrees or less. (2) The segment A and the segment C are approximately parallel with each other, or the segment B and the segment C are approximately parallel with each other.

Apparatuses for manipulating a color displayed by an article of wear comprising iron oxide colloidal nanocrystals arranged within chains are described. The apparatus includes (a) a magnetic field source, wherein a strength of a magnetic field generated by the magnetic field source is tunable to control the color displayed by the article of wear, and (b) an energy source, wherein energy generated by the energy source is applied to at least some of the chains of nanocrystals to soften materials within the article of wear immediately surrounding the chains of nanocrystals to which the energy is applied.

Metamaterial optical modulators can include one or more optical inputs, one or more optical outputs, one or more control inputs and an arrangement of a plurality of elements. The plurality of elements can include one or more variable state elements. The plurality of elements as arranged can be configured to modulate one or more properties of light passing through the metamaterial optical modulator via a change in a state of the one or more variable state elements based on one or more control signals received at the one or more control inputs.

A method of designing a meta optical device is provided. The method includes: setting, via a processor, design data for arrangement and dimensions of a nanostructure of the meta optical device, according to a function to be implemented by the meta optical device; obtaining a phase change graph with respect to a change in the dimensions; setting a shape dimension region with phase defect in the phase change graph; and substituting a shape dimension with phase defect, which is included in the shape dimension region with phase defect among the dimensions included in the design data, with a substitution value that is outside the shape dimension region with phase defect. Accordingly, a meta optical device having no phase defect is implemented.

Apparatuses for manipulating a color displayed by an article of wear comprising iron oxide colloidal nanocrystals arranged within chains are described. The apparatus includes (a) a magnetic field source, wherein a strength of a magnetic field generated by the magnetic field source is tunable to control the color displayed by the article of wear, and (b) an energy source, wherein energy generated by the energy source is applied to at least some of the chains of nanocrystals to soften materials within the article of wear immediately surrounding the chains of nanocrystals to which the energy is applied.

A fast optical switch can be fabricated/constructed, when vanadium dioxide (VO.sub.2) ultra thin-film or vanadium dioxide (VO.sub.2)/two-dimensional (2-D) material 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.