Telefonaktiebolaget Lm Ericsson (publ)

Ericsson Ab

Antonio Malacarne

Luca Poti

Fabio Cavaliere

Antonella Bogoni

Marco Secondini

Gianluca Berrettini

Luca Giorgi

Antonio D'Errico

Enrico Forestieri

Nicola Andriolli

Gianluca Meloni

Claudio Porzi

Tommaso Foggi

Francesco Fresi

Alessandra Bigongiari

A photonic radio frequency, RF, signal generation apparatus has a source to output a coherent optical signal at a carrier frequency; an optical splitter to split the signal into a first and a second optical carrier signal; an RF signal generation apparatus generating an RF signal at an initial frequency; an optical modulation apparatus modulating the first and second signals at the initial frequency to generate optical harmonic signals around each signal; a first optical filter to select an nth order optical harmonic signal of a first sign, +n, of the optical harmonics around the first signal; a second optical filter to select the nth order optical harmonic signal of an opposite sign, −n, of the optical harmonics around the second signal; and a combiner to combine the selected +n and −n signals to generate an optical beat signal forming an output photonic RF signal.

Photonic RF signal generation apparatus, network units and method

An optical transmission method () comprising steps of receiving () a communication signal comprising symbols for transmission. The method comprises performing () linear amplitude modulation of an optical carrier with the communication signal to generate an amplitude modulated optical carrier. The method comprises performing low-pass filtering () to reduce a bandwidth of the symbols to less than a Nyquist bandwidth of the symbols. The method comprises transmitting () the amplitude modulated optical carrier. The method further comprises receiving () the amplitude modulated optical carrier following transmission and performing direct detection of the received amplitude modulated optical carrier to generate a received electrical signal; and determining () received symbols from the received electrical signal using an indication of a nonlinear impulse response of the direct detection.

Optical transmission method and optical receiver apparatus for determining received symbols from a received electrical signal using an indication of a nonlinear impulse response of the direct detection and without performing equalization following the direct detection

A method of transmitting communications traffic, the method comprising steps of receiving a sequence of communications traffic bits; and mapping the sequence of communications traffic bits onto a respective one of a plurality of transmission symbols for transmission during a symbol time. Each transmission symbol is identified by a respective first symbol identifier indicative of a respective one or more of a plurality, M, of wavelengths for a transmission signal and a respective second symbol identifier indicative of a respective one or more of a plurality, N, of optical fibers on which to transmit the transmission signal.

Method of transmitting communications traffic, transmitter and communications transmission system

A transceiver () comprising a receive part () configured to receive and detect a first signal carried on an optical carrier, wherein the signal is in a first part of a RF spectrum. The transceiver () further comprises a modulator () configured to modulate the same optical carrier with a second signal in a second part of the RF spectrum. The transceiver comprises a transmit part () configured to transmit the optical carrier modulated with the second signal. The first part of the RF spectrum is separate to the second part of the RF spectrum. The first signal and/or second signal are spectrally compressed signals.

Optical transceiver

An optical flip-flop comprises first () and second () flip-flop elements arranged to respectively provide first (output) and second (output) optical outputs. Each output is in one of a plurality of states, wherein switching the output from a relatively high power state to a relatively low power state has an associated falling edge transition time, and switching the output from a relatively low power state to a relatively high power state has an associated rising edge transition time. The rising edge transition time is greater than the falling edge transition time. The optical flip-flop also comprises a processor () arranged to process the first and second outputs to provide an optical flip-flop output, being one of a plurality of state outputs, wherein switching the flip-flop output from a relatively high power state to a relatively low power state has an associated falling edge transition time, and switching the flip-flop output from a relatively low power state to a relatively high power state has an associated rising edge transition time. The processor is arranged to process the first and second outputs such that both the falling edge transition time and the rising edge transition time of the flip-flop output are independent of the rising edge transition times of both the first and second flip-flop elements. The invention also provides a method of operating the flip-flop, an optical switching arrangement and an optical switching method.

Optical flip-flop

An optical logic gate () comprising inputs () for optical signals on which to perform a chosen logical operation. An SOA () element receives such input signals to be piloted thereby in saturation and its output is connected to at least one optical filter () that filters components of signals output from the SOA and which represent a desired logical result of the signals input at the gate so that at the output () of the filter there is an optical signal as the result of the desired logical operation. A probe signal () can also be provided. An appropriate combination of power of the input, power and probe signal wavelength and central wavelength of the filter allows obtaining a plurality of logic functions such as NOR, NOT, inverted XOR, AND, OR.

Method of operating a reconfigurable and integrable optical logic gate based on a single SOA

An optical circuit comprises a bistable optical waveguide having first and second transmission states, and is more transmissive to light of a given wavelength in the second state than in the first state. First and second light sources emit light of first and second wavelengths, respectively, and are coupled to the waveguide at one end. Selectively transmitting a sufficient amount of light of the first wavelength through the waveguide switches the waveguide into the second state. Selectively transmitting a sufficient amount of light of the second wavelength through the waveguide switches it back to the first state. A sensing light source at the other end of the waveguide transmits a sensing light signal through the waveguide in the opposite propagation direction to that of light of the first and second wavelengths. A sensor detects the amount of the sensing light signal transmitted through the waveguide.

Growing community of inventors

Pisa, Italy

Antonio Malacarne