Abstract: A method for optical signal amplification in an optical communication system is presented. The optical communication system comprises an optical line terminal, a plurality of optical network units, an optical splitter and a plurality of circulators. The optical network units comprise each an optical amplifier. A first optical signal is sent in a downstream direction from the optical line terminal to a first circulator from the plurality of circulators. The first optical signal is further sent from the first circulator to a first optical network unit from the plurality of optical network units and it bypasses the optical splitter. The first optical signal is amplified in the optical amplifier of the first optical network unit to generate an amplified optical signal. The amplified optical signal is sent from the first optical network unit to the first circulator through the optical splitter and is further sent from the first circulator to a further of the plurality of optical network units.

Abstract: Proposed is a method of receiving a WDM optical upstream signal in an optical access network. The WDM signal is filtered using a first optical filter yielding a first filtered signal. The first optical filter has a flat-top shaped pass-band transfer function. Furthermore the WDM signal is filtered using second optical filter yielding a second filtered signal. The second optical filter has a pass-band transfer function that is strictly monotonically increasing for wavelength values below a center wavelength of the transfer function and that is strictly monotonically decreasing for wavelength values above the center wavelength of the transfer function. Received upstream data is derived from the first filtered signal. An optical signal power level is derived from the second filtered signal an optical signal power level. Finally, it is indicated to an optical network unit a desired direction of wavelength shift in dependence on the derives signal power level.

Abstract: A method for optical signal amplification in an optical communication system is presented. The optical communication system comprises an optical line terminal, a plurality of optical network units, an optical splitter and a plurality of circulators. The optical network units comprise each an optical amplifier. A first optical signal is sent in a downstream direction from the optical line terminal to a first circulator from the plurality of circulators. The first optical signal is further sent from the first circulator to a first optical network unit from the plurality of optical network units and it bypasses the optical splitter. The first optical signal is amplified in the optical amplifier of the first optical network unit to generate an amplified optical signal. The amplified optical signal is sent from the first optical network unit to the first circulator through the optical splitter and is further sent from the first circulator to a further of the plurality of optical network units.

Abstract: Proposed is an OLT for a passive optical wavelength division multiplex network. The network contains optical transmitters for generating downstream signals of an L-Band, as well as optical receivers for receiving upstream signals of a C-Band. Furthermore, the OLT contains a bi-directional SOA and an optical interface. The optical interface, the SOA, the transmitters and the receivers are optically coupled such that an upstream signal received at the optical interface is firstly provided to the bi-directional SOA and subsequently from the SOA to one of the receivers, and such that a downstream signal generated by one of the transmitters is firstly provided to the bi-directional SOA and then subsequently to the optical interface. The bi-directional SOA has a gain function that is not constant with respect to a wavelength of an optical signal to be amplified. Furthermore, the gain function is maximal for a wavelength located within the C-band.

Abstract: Proposed is a method of receiving a WDM optical upstream signal in an optical access network. The WDM signal is filtered using a first optical filter yielding a first filtered signal. The first optical filter has a flat-top shaped pass-band transfer function. Furthermore the WDM signal is filtered using second optical filter yielding a second filtered signal. The second optical filter has a pass-band transfer function that is strictly monotonically increasing for wavelength values below a center wavelength of the transfer function and that is strictly monotonically decreasing for wavelength values above the center wavelength of the transfer function. Received upstream data is derived from the first filtered signal. An optical signal power level is derived from the second filtered signal an optical signal power level. Finally, it is indicated to an optical network unit a desired direction of wavelength shift in dependence on the derives signal power level.

Abstract: Apparatus for amplifying signal such as a burst mode signal in an optical network. A doped fiber, for example an erbium-doped fiber is placed in a preferably passive module along an optical data transmission path. A pump port is optically connected to at least one combiner such as a WDM (wavelength division multiplexor) that is placed along the optical transmission path to add in a pump wavelength in the vicinity of the doped fiber. The apparatus, which is preferably completely passive, may be advantageously placed in communication with a remote pump light source such as a pump laser resident on a management node of the network. A second pump port may be added, as well as one or more detector ports to facilitate operation of a remote control processor, which may also be resident in a management node such as an OLT (optical line terminal) in a PON (passive optical network).

Abstract: Proposed is an OLT for a passive optical wavelength division multiplex network. The network contains optical transmitters for generating downstream signals of an L-Band, as well as optical receivers for receiving upstream signals of a C-Band. Furthermore, the OLT contains a bi-directional SOA and an optical interface. The optical interface, the SOA, the transmitters and the receivers are optically coupled such that an upstream signal received at the optical interface is firstly provided to the bi-directional SOA and subsequently from the SOA to one of the receivers, and such that a downstream signal generated by one of the transmitters is firstly provided to the bi-directional SOA and then subsequently to the optical interface. The bi-directional SOA has a gain function that is not constant with respect to a wavelength of an optical signal to be amplified. Furthermore, the gain function is maximal for a wavelength located within the C-band.

Abstract: In one embodiment, a media access controller includes first and second optical line terminals with a receiver for adjacent first and second wavelength ranges, respectively, and an optical network unit with a transmitter having a transmitter wavelength which drifts between the first and the second wavelength range. The media access controller is configured to assign the optical network unit to the first and the second optical line terminals, such that an optical burst transmitted by the optical network unit is received by the first optical line terminal and the second optical line terminal. The media access controller is configured to determine first and second qualities of the optical burst received by the first and second optical line terminals, respectively, and to determine an estimate of the transmitter wavelength based on the first quality and the second quality.

Abstract: Apparatus for amplifying signal such as a burst mode signal in an optical network. A doped fiber, for example an erbium-doped fiber is placed in a preferably passive module along an optical data transmission path. A pump port is optically connected to at least one combiner such as a WDM (wavelength division multiplexor) that is placed along the optical transmission path to add in a pump wavelength in the vicinity of the doped fiber. The apparatus, which is preferably completely passive, may be advantageously placed in communication with a remote pump light source such as a pump laser resident on a management node of the network. A second pump port may be added, as well as one or more detector ports to facilitate operation of a remote control processor, which may also be resident in a management node such as an OLT (optical line terminal) in a PON (passive optical network).

Abstract: A manner of mitigating the self heating effect of a laser or other light source such as a laser in a network node of a communication network. A self-heating mitigation module is provided, the self-heating mitigation module includes one or both of a self-heating adjustment module to accelerate self heating at the beginning of a transmission and a sub-threshold lasing module that applies a sub-threshold current between transmissions. The self-heating adjustment module and the sub-threshold lasing module are preferable both used together and driven by a common signal, for example the burst_enable signal that facilitates transmission from the light source.

Abstract: In one embodiment, a media access controller includes first and second optical line terminals with a receiver for adjacent first and second wavelength ranges, respectively, and an optical network unit with a transmitter having a transmitter wavelength which drifts between the first and the second wavelength range. The media access controller is configured to assign the optical network unit to the first and the second optical line terminals, such that an optical burst transmitted by the optical network unit is received by the first optical line terminal and the second optical line terminal. The media access controller is configured to determine first and second qualities of the optical burst received by the first and second optical line terminals, respectively, and to determine an estimate of the transmitter wavelength based on the first quality and the second quality.