Ericsson Ab

Avanex Corporation

Alcatel Lucent

Aldo Perasso

Sergio Bosso

Emilio Casaccia

Davide Frassati

Giovanni Ghione

Massimo Speciale

Marco Pirola

Massimo Amati

Masimo Speciale

Antonio Ghio

Claudio Cassinelli

An optical demultiplexer () for wavelength division multiplex WDM optical radiation comprising a plurality of wavelength channels (Ch. . . Ch) spaced over a wavelength spectrum said demultiplexer being for separating the WDM radiation into individual wavelength channels is described. The demultiplexer comprises a first demultiplexer () for dividing the W-DM radiation into a plurality of sub-bands (Ch. . . Ch, Ch. . . Ch, Ch. . . Ch, Ch. . . Ch) each comprising a plurality of adjacent wavelength channels and each of which appears at a respective output () of the demultiplexer (), and one or more demultiplexer arrangement () for separating each sub-band into individual wavelength channels each of which appears at a respective output () and is characterised in that the or each demultiplexer arrangement () comprises an optical amplifier () for optically amplifying all channels of the sub-band; a demultiplexer () for separating the channels of the sub-band such that each to appears at a respective output (); power monitoring means () for measuring the power (P. . . P) of each wavelength channel (Ch. . . Ch) at the respective output; and control means () for controlling operation of the optical amplifier () in dependence on the measured power of each wavelength channel such as control the power of each wavelength channel to a predetermined power level.

Wavelength division multiplex (WDM) optical demultiplexer

A method of piloting an optical polarization controller including a cascade of variable polarization transformers that can be driven individually to realize overall a polarization transformation between an input optical signal and an output optical signal with each transformer having predetermined maximum and minimum end driving limits. For each transformer the method includes cyclically the steps of finding an error signal output to the controller and driving a first transformer polarization variation by a predetermined amount CS in one of the two directions to check whether with this variation the error signal is reduced and, if not, driving in the opposite direction. The decision of which of the two directions to drive first is made each time and is not fixed. Equipment in accordance with the method is also described.

Polarization-controller driving method for optical fiber transmission systems and apparatus in accordance with said method

A resonant optical modulator includes an electro-optical substrate, an optical waveguide formed in the substrate and having a variable index of refraction, and an active modulator electrode formed on the substrate in relation to the waveguide to effect electro-optical variation of the index of refraction upon application to the electrode of a modulating signal. An interface port formed on the substrate provides the modulating signal to the electrode from a signal source and has an impedance. An electrical structure, formed on the substrate and coupled to the interface port and the electrode, makes an impedance of the optical modulator substantially equal to the impedance of the signal source. The electrical structure includes a delay line and a stub formed on the substrate.

Electro-optic modulators with internal impedance matching

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Genoa, Italy

Aldo Perasso