Reconfigurable non-reciprocal integrated-optics-based devices are disclosed. The non-reciprocal devices include: a phase-sensitive device, such as a microring waveguide; a magneto-optic layer; and an electromagnet. These elements are operatively coupled such that a magnetic field generated by current flow through the electromagnet gives rise to a non-reciprocal phase shift in the phase-sensitive device. The non-reciprocal phase shift leads to a difference in the way that a light signal travels in the forward and backward directions through one or more bus waveguides that are operatively coupled with the phase-sensitive element. The non-reciprocity is reversible by reversing the direction of drive current flow in the electromagnet, which enables the inter-port connectivity of the ports of these bus waveguides to be reconfigured based on the direction of the drive current flow. Examples of reconfigurable isolator and circulator embodiments are described.

A multi-channel light detection and ranging system includes a plurality of active channels, each comprising a photosensitive element arranged to be exposed to light and an analog front end circuit arranged for receiving a signal from the photosensitive element. A compensation channel comprises a compensation element and an analog front end circuit arranged for receiving signals from the compensation capacitor. A processing unit arranged for receiving signals from the active channels and the compensation channel, deriving at a compensation signal from the signal received from the compensation channel, and compensating for the crosstalk interference and/or the interference common to the analog front end circuits of the active channels, using the compensation signal.

The present invention relates to a radiofrequency oscillator comprising an optical resonator being a ring waveguide allowing the propagation of a first wave in a first direction and of a second wave in a second direction, the second direction being opposite to the first direction, and the resonator comprising an active optical medium generating a first optical line from the first wave and a second optical line from the second wave, the resonator being in contact with a part made of a material featuring a magneto-optic effect, an applier of external magnetic field of adjustable intensity on the resonator generating a frequency offset between the first wave and the second wave, and a processing circuit converting the beat between the two optical lines in a radiofrequency signal.

A radiation source for emitting terahertz radiation (6) is specified, comprising at least two laser light sources emitting laser radiation (11, 12) of different frequencies, and a photomixer (5) comprising a photoconductive semiconductor material (51) and an antenna structure (52), the photomixer (5) being configured to emit the laser radiation (11, 12) of the laser light sources (1, 2) and emitting terahertz radiation (6) with at least one beat frequency of the laser light sources, and wherein the at least two laser light sources are surface-emitting semiconductor lasers (1, 2) which are arranged in a one-dimensional or two-dimensional array on a common carrier (10).

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 present invention relates to a radiofrequency oscillator comprising an optical resonator being a ring waveguide allowing the propagation of a first wave in a first direction and of a second wave in a second direction, the second direction being opposite to the first direction, and the resonator comprising an active optical medium generating a first optical line from the first wave and a second optical line from the second wave, the resonator being in contact with a part made of a material featuring a magneto-optic effect, an applier of external magnetic field of adjustable intensity on the resonator generating a frequency offset between the first wave and the second wave, and a processing circuit converting the beat between the two optical lines in a radiofrequency signal.

A terahertz-wave generation method of generating a terahertz wave in a direction satisfying a non-collinear phase-matching condition by making pump light incident on a nonlinear optical crystal capable of generating a terahertz wave by optical parametric effect, makes the pump light incident on the nonlinear optical crystal so that a peak excited power density is equal to or greater than a predetermined terahertz-wave lasing threshold and equal to or less than a predetermined laser damage threshold, and an average excited power density is equal to or less than a predetermined photorefractive effect occurrence threshold, the pump light having a pulse width of 10 ps or more, the pulse width of 1 ns or less, and a repetition frequency of 1 kHz or more.

This invention disclosed a system and method for characteristics measurement of electromagnetic signals. The measurement system comprises a multi-repetition-rate pulsed light source, a frequency mixer for electrical signal and optical signal, and a data acquisition and processing device. The measurement system accurately determines the characteristic information of the signal to be measured, such as frequency, phase, intensity, and their variations, by measuring the low frequency mixed signal generated by the multi-repetition-rate pulsed light source and the signal to be measured in the frequency mixer. This system has the advantages of simple structure, high measurement accuracy, low cost and large measurable frequency range. The system can be applied to the measurement of various electromagnetic signals, covering the spectral range from microwave, millimeter wave, to terahertz and even light wave.

An opto-electronic oscillator (10) comprising: an optical source (12) to generate an optical carrier signal having a carrier wavelength; an optical phase modulator (14) to apply a sinusoidal phase modulation to the optical carrier signal to generate two first order sidebands having a phase difference between them; an optical phase shifter (16) comprising an optical resonator configured to apply a substantially phase-shift to one of the first order sidebands at a preselected wavelength within an optical spectrum of said first order sideband; and a photodetector (18) configured to perform optical heterodyne detection of the optical carrier signal with both: said one of the first order sidebands substantially it phase shifted by the optical resonator; and the other of the first order sidebands, to generate an electrical carrier signal (20), and wherein a first part of the electrical carrier signal (20a) is delivered to an electrical output (22) and a second part of the electrical carrier signal (20b) is delivered to the optical phase modulator as a drive signal.

An apparatus embedded with one or more terahertz transceivers is described. The one or more terahertz transceivers based on at least one optical source is provided to facilitate wireless communication in the apparatus, where the apparatus is embedded with one or more planar antennas. The transceiver operates in terahertz and may be coupled to two different antennas, one for transmission and the other for reception.