Telefonaktiebolaget Lm Ericsson (Publ)

Ericsson Ab

Marconi Communications Gmbh

Rodolfo Di Muro

Paolo Fella

Antonella Bogoni

Luca Poti

Gianluca Berrettini

Mirco Scaffardi

Bimal Nayar

An optical signal amplifier for use in optical networks operating in a ring configuration comprising a first doped optical fiber loop pumped by a first laser and a second optical fiber loop pumped by a second laser.

Optical signal amplifier, method of optical amplification and optical network

An optical transmitter apparatus comprises at least three input transmitters that each provide at an output an NRZ optical signal, at least two of the NRZ optical signals having substantially the same bit rate, each of the signals having a bit rate which is less than 100 Gbit/s and the sum of the bit rates of all of the at least three transmitters being equal to or greater than 100 Gbit/s, an NRZ to RZ converter associated with each transmitter which converts each NRZ signal into an optical RZ signal, an optical time division multiplexer which converts the RZ signals into at least two further signals, and a polarization multiplexer which processes the two further signals to provide two output signals of differing polarization.

Ethernet transmitter apparatus

A method of producing green light signals, comprising coupling pump signals from at least one pump source into at least one erbium doped fiber (EDF) which cause ground state absorption (GSA), and excited state absorption (ESA) in erbium ions of the EDF, which produces green light signals, wherein the majority of the pump signals have a wavelength at which the probability of occurrence of ESA in the EDF is greater than the probability of occurrence of GSA in the EDF. The majority of the pump signals may have a wavelength in the range approximately 920 nm to approximately 980 nm, or in the region of 960 nm. An erbium doped fiber amplifier (EDFA) () for amplifying traffic-carrying signals may be pumped by green light signals produced by this method. A laser which produces green light signals may be constructed, which comprises at least one EDF, coupled to at least one pump source to receive pump signals therefrom, which cause GSA, and ESA in erbium ions of the EDF, which produces green light signals, the majority of the pump signals having a wavelength at which the probability of occurrence of ESA in the EDF is greater than the probability of occurrence of GSA in the EDF.

Erbium doped fibres

A system and method for controlling the gain of an optical amplifier receiving one or more optical input signal channels at a first end include a source for generating a gain control signal, which is input to the optical amplifier at the opposite end to the input signal channels. The gain control signal is generated at a power level that produces stimulated Brillouin scattering (SBS) in the optical amplifier.

Optical system

A Raman amplifier for amplifying WDM radiation propagating along an optical fiber, the WDM radiation comprising a plurality of radiation components each having a selected waveband, comprises a plurality of optical radiation generators operable to generate pump radiation of a selected wavelength and power, the radiation being coupled into the fiber to optically amplify the WDM radiation. The generators are wavelength tuneable, and the power of the radiation components of the WDM radiation is measured after it has propagated along the fiber and has been amplified. The wavelength and power of operation of the generators are controlled in dependence upon the measured powers such as to make the measured powers substantially equal in magnitude and of a selected magnitude. To reduce polarization dependent gain where the pump radiation propagates in a direction along the optical fiber that is counter to the direction of propagation of the WDM radiation, each generator preferably comprises a plurality of radiation sources, preferably three, each one being operable to generate radiation having the same wavelength but with a different state of polarization. Advantageously, the three radiation sources are operable to generate radiation whose state of polarization is shifted by 60&#xb0; to each other and which are combined using a polarization maintaining multiplexer.

Growing community of inventors

Coventry, United Kingdom

Rodolfo Di Muro