Disclosed are a terahertz signal generation apparatus and a terahertz signal generation method using the same. The terahertz signal generation apparatus includes first and second resonators configured to respectively output an optical signal of a first resonant frequency and an optical signal of a second resonant frequency from an optical signal input through a gain medium, an optical modulator configured to optically modulate the output optical signal of the second resonant frequency, an optical combiner configured to combine the CW optical signal of the first resonant frequency and the modulated optical signal of the second resonant frequency, and a signal generator configured to generate a terahertz signal using heterodyne beating between the CW optical signal of the first resonant frequency and the modulated optical signal of the second resonant frequency, wherein the first resonant frequency and the second resonant frequency are processed to have a predetermined frequency difference.

An imaging device includes a modulator, a first grating pattern constituted by a plurality of lines, and a second grating pattern having a phase deviating from a phase of the first grating pattern, and modulates light intensity. The imaging device receives a first image signal output by the first grating pattern and a second image signal output by the second grating pattern, calculates difference data and a range of a difference between the first image signal and the second image signal, generates and sets a data conversion parameter at a regular interval from the difference data that is continuously input on the basis of the range of the difference and the difference data, generates compression image data by using the difference data and the data conversion parameter, compresses the generated compression image data, and includes information indicating the range of the difference into the compressed data.

An optical resonator frequency comb comprising a main optical resonator being made of a resonator material, which has a third order nonlinearity and an anomalous resonator dispersion; a continuous wave (cw) laser configured for supplying continuous laser light into an optical waveguide, which is coupled with the main optical resonator. The cw laser, the optical waveguide and the main optical resonator are arranged for resonantly coupling the cw laser light into the main optical resonator for forming a single dissipative soliton circulating in the main optical resonator corresponding to the generation of a frequency comb. Furthermore, the optical resonator frequency comb further comprises an auxiliary optical element configured to induce a phase shift to a frequency comb component at the cw laser frequency to enhance the conversion efficiency of a generated frequency comb. The disclosure also relates to an associated method.

A tunable optical metamaterial system includes a tunable optical metamaterial, an actuator module to selectively activate the tunable optical metamaterial, and a control system to selectively control the actuator module. The tunable optical metamaterial includes a substrate composed at least in part of an electroactive polymer (EAP), and an optically active particle array that includes a plurality of optically active elongated members populated spaced apart on the substrate in two or more orientations to form confocal lenses that are optically responsive to the expansion of the substrate. The control module, is configured to control the optical properties of the tunable optical metamaterial by causing the electrical activation of the substrate via the actuator module to selectively expand the substrate in a manner that alters the spacing between the optically active elongated members.

A watch case (10) comprising a middle (11) to which a crystal (12) and a back (13) are fastened so as to form an internal volume, the watch case (10) including, in the internal volume, an external part component (14) whereon a stack of thin layers (15) comprising a substrate layer (150), a solid-state phase switching layer (151) inserted between a transparent encapsulation layer (152) and a spacing layer (153) separating the phase switching layer (151) from the substrate layer (150) is deposited, the phase switching layer (151) being configured so as to have a refractive index capable of varying under exposure from light rays so as to impart to the stack of thin layers (15) at least two interferential colours.

A tunable optical metamaterial system includes a tunable optical metamaterial, an actuator module to selectively activate the tunable optical metamaterial, and a control system to selectively control the actuator module. The tunable optical metamaterial includes a substrate composed at least in part of an electroactive polymer (EAP), and an optically active particle array that includes a plurality of optically active elongated members populated spaced apart on the substrate in two or more orientations to form confocal lenses that are optically responsive to the expansion of the substrate. The control module, is configured to control the optical properties of the tunable optical metamaterial by causing the electrical activation of the substrate via the actuator module to selectively expand the substrate in a manner that alters the spacing between the optically active elongated members.

Various embodiments may provide a device for controlling an electromagnetic wave according to various embodiments. The device may include a medium. The device may further include an array of elements in contact with the medium and may be configured to receive the electromagnetic wave. Each element of the array of elements may include a phase change material configured to switch from, at least, a first state to a second state in response to an external input, thereby changing an optical property of the respective element to control the electromagnetic wave.

Aspects relate to a photonic processing system, a photonic processor, and a method of performing matrix-vector multiplication. An optical encoder may encode an input vector into a first plurality of optical signals. A photonic processor may receive the first plurality of optical signals; perform a plurality of operations on the first plurality of optical signals, the plurality of operations implementing a matrix multiplication of the input vector by a matrix; and output a second plurality of optical signals representing an output vector. An optical receiver may detect the second plurality of optical signals and output an electrical digital representation of the output vector.

Devices, methods for analog-to-digital converters (ADCs) that perform high-dynamic range measurements based on optical techniques are disclosed. In one example aspect, an optical encoder includes a polarization rotator configured to receive a train of optical pulses, and an electro-optic (EO) modulator coupled to an output of the polarization rotator. The EO modulator is configured to receive a radio frequency (RF) signal and to produce a phase modulated signal in accordance with the RF signal. The optical encoder also includes a polarizing beam splitter coupled to the output of the EO modulator; and an optical hybrid configured to receive two optical signals from the polarizing beam splitter and to produce four optical outputs that are each phase shifted with respect to one another.

The invention is notably directed to a transflective display device. The device comprises a set of pixels, wherein each of the pixels comprises a portion of bi-stable, phase change material, hereafter a PCM portion, having at least two reversibly switchable states, in which it has two different values of refractive index and/or optical absorption. The device further comprises one or more spacers, optically transmissive, and extending under PCM portions of the set of pixels. One or more reflectors extend under the one or more spacers. An energization structure is in thermal or electrical communication with the PCM portions, via the one or more spacers. Moreover, a display controller is configured to selectively energize, via the energization structure, PCM portions of the pixels, so as to reversibly switch a state of a PCM portion of any of the pixels from one of its reversibly switchable states to the other. A backlight unit is furthermore configured, in the device, to allow illumination of the PCM portions through the one or more spacers. The backlight unit is controlled by a backlight unit controller, which is configured for modulating one or more physical properties of light emitted from the backlight unit. The invention is further directed to related devices and methods of operation.