Alcatel

Alcatel Lucent

Alcatel-lucent USA Inc.

Nokia of America Corporation

Nokia Solutions and Networks Oy

Alcatel Submarine Networks

Gabriel Charlet

Jeremie Renaudier

Po Dong

Thomas Pfeiffer

Christian Simonneau

Erwan Corbel

Loïc Becouarn

Denis Penninckx

Ludovic Noirie

Patrick Brindel

Romain Brenot

Yann Frignac

Francesco Vacondio

Pierre Peloso

Massimiliano Salsi

Sébastien Bigo

Laurent Schmalen

Oriol Bertran-Pardo

Jean-Christophe Antona

Christian Dorize

Patrice Tran

Thibaut Fauconnier

Eric Barnasson

Haik Mardoyan

Rafael Rios Muller

Jérémie Renaudier

Olivier Courtois

Rafael Rios Müller

Oriol Bertran Pardo

Clemens Koebele

An amplification device includes an element for splitting an input optical signal into first and second optical signals having first and second polarization modes, first and second amplification stages each including polarized SOAs for amplifying the first and second optical signals depending on driving currents, an intermediate processing stage for compensating optical characteristics of the optical gain bandwidth of the first amplification stage depending on driving currents, an element for combining the first and second optical signals outputted by the second amplification stage to produce an output optical signal, and a control means producing the driving currents depending on information representative of powers of the first and second optical signals before the polarized SOAs of each amplification stage and on a targeted power of the output optical signal.

Amplification device with amplification stages with polarized SOAs and processing stage, for amplifying optical signals in a WDM transmission system

A method and device for optical data transmission are disclosed. Data bits are transmitted in the form of data symbols, by modulating an optical signal in dependence on the data bits and in accordance with two or more constellation schemes. The data bits are transmitted, by generating first data symbols, which represent respective sets of data bits containing an even number of data bits. The first data symbols are generated, by modulating the optical signal in accordance with a first constellation scheme. Furthermore, the data bits are transmitted, by generating second data symbols, which represent respective sets of data bits having an odd number of data bits. The second data symbols are generated, by modulating the optical signal in accordance with a second constellation scheme. The first and the second data symbols are generated at a predefined symbol rate, such that the first and the second data symbols are interleaved in time.

Method and device for optical data transmission

A modular optical device having a set of optoelectronic modules that enables the device to operate, e.g., as a WDM or multichannel transceiver. In an example embodiment, the set of optoelectronic modules includes a laser module, a modulator module, and an optical-to-electrical converter module, all mounted on the same circuit board and optically and electrically connected for the intended application. Each of the optoelectronic modules comprises a respective stack of integrated circuits, at least one of which is a photonic integrated circuit (PIC). Some of the PICs may be configurable for different applications, with the configuration setup being carried out using electrical control signals and/or optical connections of the PICs. The modular structure of the device enables the manufacturer to provide customized solutions to different customers according to their respective specifications while using the same device architecture and/or to interchangeably use parts obtained from different suppliers to engineer those solutions.

Modular optical device and modules therefor

A technique is provided for a receiver of an optical signal. The technique includes an apparatus that is configured to input digitized samples of the optical signal at a first sampling rate. The apparatus is further configured to filter the digitized samples based on a plurality of filter coefficients to obtain filtered samples of the optical signal at a second sampling rate. The second sampling rate is different from the first sampling rate. The apparatus is further configured to output the filtered samples of the optical signal at the second sampling rate.

Apparatus, method and computer program for a receiver of an optical signal

An optical transmitter for transmitting a multilevel amplitude-shift-keying modulated signal includes an optical modulator for modulating an optical signal with a multilevel amplitude-shift-keying modulation, and a spectral filter adapted to increase a high-frequency component of the modulated optical signal relatively to a central frequency component. The multilevel ASK modulation is quaternary ASK and the symbol rate of the optical modulator is above 40 Gbaud. An optical link connects the optical transmitter to a quadratic direct detection optical receiver.

Optical transmitter for transmitting a multilevel amplitude-shift-keying modulated signal

An exemplary method and apparatus are provided for high efficiency wavelength division multiplexing (WDM) optical communication systems. An optical transmitter adapted to transmit an optical signal on an optical WDM transmission channel to a corresponding optical receiver is described. The optical transmitter comprises a symbol generation unit adapted to convert input data into a sequence of data symbols at a symbol rate B; with B being a real number greater zero; an amplitude modulation unit adapted to modulate an amplitude of every Ndata symbol in a sequence derived from the sequence of data symbols, thereby creating a modulated sequence of data symbols; wherein N is an integer; wherein N&#x3e;2; and a digital-to-optical converter adapted to convert a sequence derived from the modulated sequence of data symbols into an optical signal to be transmitted to the optical receiver.

Clock recovery method for ultra dense WDM systems

To that end, it is an object of the invention to provide a method for converting a high-speed digital signal in the form of optical pulses intended to be transmitted within optical guides, within which the signal is converted into a series of optical pulses in three possible phase states (&#x3c0;/6, 5&#x3c0;/6, &#x2212;&#x3c0;/2) separated from one another two-by-two by an angle greater than &#x3c0;/2.

Method and device for converting a digital signal into optical pulses

A data transmitter (A, B, C, D) wherein, in a first operating mode, the first and second carrier signals are mutually phase-shifted, and the data module generates said first and second data signals based on different data, so as to produce, at the transmitter's output, a modulated signal exhibiting a first constellation of states (A, B, C, D) in a complex plane, and, in a second operating mode of the transmitter, the data module generates said first and second data signals correlated with one another based on common data, so as to produce, at the transmitter's output, a modulated signal exhibiting a second constellation of states (A, D; E, F) in the complex plane that is more reduced and more dispersed then said first constellation of states.

Transmitter for multi-format data

The embodiments of the present invention describe a method for optimizing the capacity of an optical communication network that uses wavelength division multiplexing, wherein the spectral distribution of the signals intended to be transmitted over a plurality of channels is done dynamically through the use of a variable spectrum grid whose spectral spacings between two successive channels are determined based on the spectral width of said signals and in which dynamic filtering of said signals is carried out before their transmission in order to adjust their spectral width based on the available spectral space, and thereby reduce crosstalk between adjacent channels when the signals are transmitted.

Method for optimizing the capacity of optical communication networks

The invention relates to a modulation scheme for optical communication, in particular for fiber optics communication. According to invention, an optical signal is generated, both phase and polarization of which modulated in dependency of the data to be transmitted. Preferably, the generated optical signal comprises a sequence of symbols (-) and each symbol (-) has one of two different phase states and one of two different orthogonal polarization states. Bits of the data stream to be transmitted are encoded both in the phase state of a symbol (or in the phase state difference between subsequent symbols) and in the polarization state of the symbol (or in the polarization state difference between the subsequent symbols).

Combined phase and polarization modulation for optical communication

A transmitter () for generating a DQPSK-modulated optical signal, including: a splitter () for dividing an optical carrier signal into a first and second branch (), a first and second Mach-Zehnder interferometer () in the first and second branch (), respectively, a phase shifter () in one of the branches () generating a nominal phase shift of .pi./2, and a combiner (') for combining the optical output signals of the two branches (). The transmitter () has a feedback circuit () generating at least a first and second bias signal (to) for adjusting a bias of at least the first and second Mach-Zehnder interferometers (), the feedback circuit () includes a detector for generating at least a first and second feedback signal from a sample signal extracted from the optical signal after the combiner (&#x2032;), and for each bias signal: a local oscillator generating an auxiliary signal modulating the bias signal (to) at a pre-defined frequency (f, f, f), a lock-in detector determining a phase difference between the feedback signal and the auxiliary signal, and a bias circuit for generating the bias signal (to) from an output signal of the lock-in detector, wherein the pre-defined frequencies of the auxiliary signals (f, f, f) are different from one another (f.noteq.f.noteq.f) and preferably no integer multiples of each other.

Fiber optical transmission system, transmitter and receiver for DQPSK modulated signals and method for stabilizing the same

A method of operating an optical transmission system is described. The transmission system is provided with a bit-to-bit polarization interleaved bitstream having a given bitrate. The transmission system comprises a birefringent element and/or a decision circuit. The birefringent element and/or the decision circuit are triggered by a trigger signal having a frequency of half of the bitrate.

Method of operating an optical transmission system with a bit-to-bit polarization interleaved bitstream

A method for modulating an optical signal includes the following steps: modulating the intensity of the optical signal with a nonreturn-to-zero bit signal, and modulating the phase of the optical signal with a periodic phase-shift signal creating an alternating &#x3c0;-phase shift every second, third or more consecutive bit. An optical transmitter for performing the above method comprises a first modulator () modulating the intensity of the optical signal with a nonreturn-to-zero bit signal, and a second modulator () modulating the phase of the optical signal with a periodic phase-shift signal creating an alternating &#x3c0;-phase shift every second, third or more consecutive bit.

Method for modulating an optical signal and optical transmitter

A device for processing a digital signal of an optical transmission system is described. The device comprises: a polarization beam splitter for receiving the signal, a phase shifter for shifting the phase of the signal at the orthogonal output of the polarization beam splitter, and means for combining the signal at the parallel output of the polarization beam splitter and the shifted signal.

Device and a method for processing a digital signal in a bit-to-bit polarization-interleaved format of an optical transmission system

An optical amplification unit comprises at least one optical amplifier for amplifying an optical signal and a filter preceding or following the optical amplifier. The optical amplifier comprises a first measuring device for measuring a property of an input signal of the optical amplifier, a second measuring device for measuring a property of an output signal of the optical amplifier, and a control circuit for controlling a gain characteristic of the optical amplifier in dependence of said input and output signal properties. The filter exhibits a wavelength-dependent attenuation of the optical signal. The optical amplification unit is connectable to an optical fiber span and the filter is adapted to compensate for a span loss tilt caused by said optical fiber span. An optical transmission system with at least one such optical amplification unit and corresponding methods.

Growing community of inventors

Villiers-le-Bacle, France

Gabriel Charlet