The present invention relates to the field of magnetic assemblies and processes for producing optical effect layers (OELs) comprising magnetically oriented non-spherical magnetic or magnetizable pigment particles on a substrate. In particular, the present invention relates to magnetic assemblies processes for producing said OELs as anti-counterfeit means on security documents or security articles or for decorative purposes.

A control circuit for controlling a timing, a pulse length, a valve electric field having the certain magnitude, and a pulse envelope of the valve electric field, so as to coherently control a response of a region of an insulator to a probe electric field, the response controlled with a temporal resolution equal to the pulse length and matching the pulse envelope.

In one embodiment, a chromatic device includes a transparent conductive substrate, an active layer provided on the conductive substrate, the active layer comprising a conducting polymer, an electrolyte layer in contact with the conductive substrate and the active layer, the electrolyte comprising an oxidant and a salt but not comprising an acid, and a metal element configured to be selectively placed in and out of direct electrical contact with the conductive substrate or the active layer, wherein the active layer has a color that blocks light when the metal element is not in electrical contact with the conductive substrate but changes to a translucent color that transmits light when the metal element is placed in electrical contact with the conductive substrate or the active layer, wherein the active layer changes color without applying external energy to the active layer.

In one embodiment, a chromatic device includes a transparent conductive substrate, an active layer provided on the conductive substrate, the active layer comprising a conducting polymer, an electrolyte layer in contact with the conductive substrate and the active layer, the electrolyte comprising an oxidant and a salt but not comprising an acid, and a metal element configured to be selectively placed in and out of direct electrical contact with the conductive substrate or the active layer, wherein the active layer has a color that blocks light when the metal element is not in electrical contact with the conductive substrate but changes to a translucent color that transmits light when the metal element is placed in electrical contact with the conductive substrate or the active layer, wherein the active layer changes color without applying external energy to the active layer.

A high-electron mobility transistor (HEMT) array terahertz wave modulator loaded in a waveguide is provided, which belongs to the technical field of electromagnetic functional devices and focuses on fast dynamic functional devices in the terahertz band. The device comprises a waveguide cavity and a modulation chip. The modulation chip comprises a semiconductor material substrate, a heterostructure material epitaxial layer, an artificial microstructure, and a socket circuit. The applied voltage controls the distribution change of the two-dimensional electron gas in the HEMT, which in turn controls the resonance mode conversion in the artificial microstructure, thereby control the transmission of electromagnetic waves in the waveguide. The modulator has a modulation depth of up to 96% and a modulation rate above 2 GHz.

In one embodiment, a chromatic device includes a transparent conductive substrate, an active layer provided on the conductive substrate, the active layer comprising a conducting polymer, an electrolyte layer in contact with the conductive substrate and the active layer, the electrolyte comprising an oxidant and a salt but not comprising an acid, and a metal element configured to be selectively placed in and out of direct electrical contact with the conductive substrate or the active layer, wherein the active layer has a color that blocks light when the metal element is not in electrical contact with the conductive substrate but changes to a translucent color that transmits light when the metal element is placed in electrical contact with the conductive substrate or the active layer, wherein the active layer changes color without applying external energy to the active layer.

An optical modulation element 100 includes a rib type optical waveguide that includes a rib portion 112 that has a P-N junction, a P-type slab area 114 that continuously extends from a P type area of the rib portion 112, and an N-type slab area 116 that continuously extends from an N type area of the rib portion 112. A first thin film 130 is formed on the P-type slab area 114 and is made of a material having an electron affinity that is different from that of the P-type slab area 114.

A transmissive polarization control device includes: a semiconductor layer having a first surface and a second surface opposite to the first surface, the semiconductor layer including: a first conductivity type region having a conductivity type, a second conductivity type region having a conductivity type, and a pn junction located between the first and second conductivity type regions; a loop electrode disposed on the first surface and configured such that an electric current flowing through the loop produces a magnetic field in a direction penetrating the pn junction; and a near-field light formation region in which an impurity of the first conductivity type introduced as a dopant into the first conductivity type region for formation of near-field light is distributed. A polarization direction of linearly polarized light traveling through a region surrounded by the loop electrode and the near-field light formation region is rotated according to the electric current.

An electroabsorption modulator that operates based on electroabsorption of a surface plasmon polariton mode is improved by various structural changes and/or selection of different materials. For example, at least a portion of the waveguide may be made to be conductive, e.g., by doping. Also, layers that make up the modulator structure may be placed along sides of waveguides in addition to or instead of simply on the top thereof. High permittivity gate dielectric materials may be employed. Also, materials other than ITO may be employed as a transparent conductor. Such an improved plasmonic electroabsorption modulator can be fabricated using standard semiconductor processing techniques and may be integrated with standard photonic integrated circuits, including silicon photonics and compound semiconductor-based platforms. Advantageously, high-speed, low-voltage operation over a wide spectrum of wavelengths may be achieved.

A transmissive polarization control device includes: a semiconductor layer having a first surface and a second surface opposite to the first surface, the semiconductor layer including: a first conductivity type region having a conductivity type, a second conductivity type region having a conductivity type, and a pn junction located between the first and second conductivity type regions; a loop electrode disposed on the first surface and configured such that an electric current flowing through the loop produces a magnetic field in a direction penetrating the pn junction; and a near-field light formation region in which an impurity of the first conductivity type introduced as a dopant into the first conductivity type region for formation of near-field light is distributed. A polarization direction of linearly polarized light traveling through a region surrounded by the loop electrode and the near-field light formation region is rotated according to the electric current.