Centre National De La Recherche Scientifique

Université Grenoble Alpes

Institut National De La Recherche Scientifique

Hugues Guillet De Chatellus

José Azaña

Reza Maram

José Azana

Guillaume Bourdarot

Konatham Saikrishna Reddy

Jean-Philippe Berger

A wideband device for the spectral analysis of a signal of interest includes a source designed to generate the signal of interest; an optical splitter element designed to spatially split the signal of interest into a first signal and a second signal; a first frequency-shifting optical cavity comprising a first frequency shifter designed to shift the optical frequency of the first signal by a first frequency fper round trip in the first cavity, the first cavity having a first trip time τ; a second frequency-shifting optical cavity comprising a second frequency shifter designed to shift the optical frequency of the second signal by a second frequency fper round trip in the second cavity, the second cavity having a second trip time τ; the first and the second optical cavity being designed such that a maximum number of round trips of the signal in the first and the second cavity is equal to predetermined N; a detector designed to coherently detect the first signal transmitted by the first cavity and the second signal transmitted by the second cavity and generate a photocurrent proportional to a luminous intensity detected by the detector, an analog low-pass filter designed to filter frequencies of the photocurrent that are lower than min (f/2, f/2) a processor configured to compute a square modulus of the photocurrent filtered by the low-pass filter, from which a temporal representation of frequency information of the signal of interest is determined.

Device for wide-band spectral analysis of a signal of interest

A wideband device for measuring the cross-correlation of a first signal and a second signal, includes a first frequency-shifting optical cavity comprising a first frequency shifter designed to shift the optical frequency of the first signal by a first frequency fper round trip in the first cavity, the first cavity having a first trip time τ; a second frequency-shifting optical cavity comprising a second frequency shifter designed to shift the optical frequency of the second signal by a second frequency fper round trip in the second cavity, the second cavity having a second trip time τ; the first and the second optical cavity being designed such that a maximum number of round trips of the first and the second signal in the first and the second cavity is equal to predetermined N, a detector designed to coherently detect the first signal transmitted by the first cavity and the second signal transmitted by the second cavity and generate a photocurrent (Tr) proportional to a luminous intensity detected by the detector, a low-pass filter designed to filter frequencies of the photocurrent that are lower than min (I), a processor configured to compute a Fourier transform of the photocurrent, so as to generate an output signal that is representative (II).

Wide-band device for measuring the cross-correlation of signals

A method and a system for generating a time-frequency representation of an aperiodic continuous input signal comprising generating a periodic train of short pulses having a repetition frequency, and sampling the signal temporally using the periodic train of short pulses to obtain a temporally sampled signal, the temporally sampled signal comprising a plurality of sampled copies of the input signal, each sampled copy being spaced in function of the repetition frequency of the periodic train of short pulses. The temporally sampled signal is delayed based on the repetition frequency to obtain a delayed temporally sampled signal comprising a plurality of delayed sampled copies, a spectral representation of a given delayed sampled copy being delayed in function of the repetition frequency. The delayed temporally sampled signal is evaluated over consecutive time slots to obtain, for each consecutive time slot, a respective output signal in the time-frequency domain.

Method and system for generating time-frequency representation of a continuous signal

Photonic devices for generating linearly frequency modulated arbitrary microwave signals comprise a laser, and assembly for forming the emitted signal and a photoreceiver the passband of which is in the domain of the microwave frequencies. The forming assembly comprises: a first beam splitter; a first optical channel including a frequency-shifting loop comprising a beam splitter, a first optical amplifier, an optical isolator, a first spectral optical filter and an acousto-optical frequency shifter; a second optical channel including an electro-optical frequency shifter; a second beam splitter; a second optical amplifier; and a second optical filter; the acousto-optical frequency shift, the electro-optical frequency shift and the amplification gain of the first optical amplifier being adjustable.

Growing community of inventors

Corenc, France

Hugues Guillet De Chatellus