Abstract: According to an example aspect of the present invention, there is provided an apparatus comprising a first part (110) which comprises a first light-based communication port (114) and a network interface (112), a second part (120) which comprises a non-volatile memory (122) and a second light-based communication port (124), and wherein the apparatus is configured to deactivate at least one of the first light-based communication port (114) and the second light-based communication port (124) responsive to determining that a read or write operation in the non-volatile memory (122) is complete.

Abstract: A node is configured for deployment in an optical network. The node includes an analog switch for routing an optical packet between input ports and output ports. The node also includes digital processing circuitry configured to generate first configuration information based on the optical packet prior to providing the optical packet to the analog switch. The analog switch is configured to route the optical packet between the input ports and the output ports based on the first configuration information in response to the optical packet arriving at the node in a first time interval. The optical packet is not processed by the digital processing circuit or results of processing are not used to configure the analog switch during a second time interval. The analog switch routes the optical packet between the input and output ports based on second configuration information during the second time interval.

Abstract: An exemplary technique is provided for a scalable architecture for a network node that allows a very high switching capacity. The network node has a number of packet optical add drop multiplexers (POADMs), a number of dual line cards, respectively associated with the POADMs, and an optical switch matrix. Each POADM has an input and an output line interface and serves to selectively add and drop optical packets into and from packet timeslots of output and input wavelength-multiplexed optical signals transmitted and received at said output and input line interfaces, respectively. The dual line cards serve to electrically process and buffer packets to be added and dropped. The optical switch matrix configurably interconnects internal optical interfaces contained within the dual line cards on a packet by packet basis.

Abstract: An exemplary technique is provided for a scalable architecture for a network node that allows a very high switching capacity. The network node has a number of packet optical add drop multiplexers (POADMs), a number of dual line cards, respectively associated with the POADMs, and an optical switch matrix. Each POADM has an input and an output line interface and serves to selectively add and drop optical packets into and from packet timeslots of output and input wavelength-multiplexed optical signals transmitted and received at said output and input line interfaces, respectively. The dual line cards serve to electrically process and buffer packets to be added and dropped. The optical switch matrix configurably interconnects internal optical interfaces contained within the dual line cards on a packet by packet basis.

Abstract: A bidirectional optical amplifier (1) is arranged to be passed through in one direction by a downstream optical signal (SDS) and in an opposite direction by an upstream optical signal (SUS), and comprises: a first optical circulator (2) having three ports, a first port of the first optical circulator defining a first connector (8) at one end of the bidirectional optical amplifier, a second optical circulator (3) having three ports, a first port of the second optical circulator defining a second connector (9) at an opposite end of the bidirectional optical amplifier, a downstream unidirectional optical amplifier (4) connected between a second port of the first optical circulator and a second port of the second optical circulator so as to define a downstream amplification path (5) for the downstream optical signal, and an upstream unidirectional optical amplifier (6) connected between a third port of the first optical circulator and a third port of the second optical circulator so as to define an upstream ampli

Abstract: A bidirectional optical amplifier (1) is arranged to be passed through in one direction by a downstream optical signal (SDS) and in an opposite direction by an upstream optical signal (SUS), and comprises: a first optical circulator (2) having three ports, a first port of the first optical circulator defining a first connector (8) at one end of the bidirectional optical amplifier, a second optical circulator (3) having three ports, a first port of the second optical circulator defining a second connector (9) at an opposite end of the bidirectional optical amplifier, a downstream unidirectional optical amplifier (4) connected between a second port of the first optical circulator and a second port of the second optical circulator so as to define a downstream amplification path (5) for the downstream optical signal, and an upstream unidirectional optical amplifier (6) connected between a third port of the first optical circulator and a third port of the second optical circulator so as to define an upstream ampli

Abstract: The field of the invention is that of switching optical signals with carrier wavelength conversion capacity, comprising a set of input ports (PE1-PEn), a set of output ports (PS1-PSn) functionally connected to the input ports so that an input signal presented to one of the input ports may be selectively routed to at least one of the output ports, and wavelength conversion means (34) providing a capacity for converting an input signal carrier wavelength to at least one other output port output wavelength.

Abstract: A passive optical network comprises at least one communication facility, termed network head, coupled to at least two communication facilities, termed remote, by transmission and routing means. The network head is charged with transmitting to the remote facilities an alternation of a first portion of an optical carrier, modulated by data to be transmitted according to a chosen bit rate and lasting a first time interval, and of a second portion of this optical carrier, modulated by a clock signal at a base frequency corresponding to the bit rate and lasting a second time interval.

Abstract: A device (D) is dedicated to optical switching in a switching node (NC) of a transparent optical network. This device (D) comprises i) at least one input port adapted to be coupled to an upstream optical line (FE1-FE4) dedicated to the transport of multiplexed channels, ii) at least one exit point, iii) switching means (MC) coupling each input port at least to each exit point, and iv) processing means (MT1-MT4) adapted to add to the channels that reach each input port a signature including first information representative of that switching node (NC), and where applicable the input port that received them.

Abstract: An all-optical clock recovery system for recovering the clock from a received optical signal with a short response time and without patterning effects includes a first optical clock recovery device adapted to supply a first optical clock signal in response to the received optical signal and a second optical clock recovery device adapted to supply a second optical clock signal in response to the first optical clock signal. Applications include regenerating optical packets in asynchronous optical packet-switched telecommunication networks.

Abstract: An optical packet node for receiving and transmitting optical packets is disclosed. A multiwavelength band splitting device splits received optical packets transmitted via multiwavelength bands into at least three groups, each group including one multiwavelength band. A multiwavelength band combining device combine the three groups of multiwavelength bands. At least two optical packet add drop multiplexers are placed between the multiwavelength band splitting device and the multiwavelength band combining device. Each optical packet add drop multiplexer adds and drops at least one individual wavelength to a respective multiwavelength band group. A load balancing stage is connected to the optical packet add drop multiplexers to provide an interconnection between at least two wavelength bands.

Abstract: Packets conveying data are received by a router via input ports which impose on them optical carrier waves whose wavelengths correspond to the ports. Respective time-delays are applied to the packets and they are broadcast to spatial selectors that transmit them to spectral selectors. Amplifiers are distributed over the paths of the packets and the paths are organized in such a manner as to limit the number of semiconductor optical switches in the selectors and to minimize noise and optical crosstalk affecting the packets.

Abstract: The field of the invention is that of switching optical signals with carrier wavelength conversion capacity, comprising a set of input ports (PE1-PEn), a set of output ports (PS1-PSn) functionally connected to the input ports so that an input signal presented to one of the input ports may be selectively routed to at least one of the output ports, and wavelength conversion means (34) providing a capacity for converting an input signal carrier wavelength to at least one other output port output wavelength.

Abstract: A method for synchronizing optical signals conducted via different optical waveguides to an optical network node, wherein the variations in propagation time of the optical signals are compensated by adjustable optical delay circuits of a synchronizing device. To set a new delay for one of the optical waveguides, one of the adjustable delay circuits, already switched into the passive state, is set at the desired delay. This delay circuit is then switched into the active state by means of a high-speed optical switch, and the previously active delay circuit is switched into a passive state.

Abstract: The invention relates to a switch (112) for optical signals and which has a number of outputs at least equal to the number of inputs and include means whereby an input signal is routed to at least one of those outputs. Each input receives information modulating optical carriers at different wavelengths. The switch (112) includes means (12611, 12612, . . . , 126NB) for grouping all the carriers received into non-contiguous subsets of carriers (G11, . . . , G1B, . . . , GN1, . . . , GNB) and means (1291, 1292, . . . , 129NB) for selecting blocks of carriers from the same subset of carriers. The information corresponding to each subset of optical carriers is thus routed in blocks to the same subset output. Switching the carriers at the subset level improves the quality of the output signal and limits the number of components for the same total quantity of information switched.

Abstract: To increase the bit rate of wavelength division multiplexed optical data switched in a photonic switching matrix, whilst maintaining a high bandwidth, a wavelength selector and converter includes a demultiplexer with n outputs respectively connected to n inputs of a coupler via n wavelength converters. Each wavelength converter has an optical gate function and selectively supplies converted signals conveyed by the same wavelength. Applications include optical packet switching.

Abstract: A hybrid spatial and wavelength selector for optical switching matrices includes a guide system defining paths between input ports receiving light waves having diverse wavelengths and at least one output port. Gates on the paths are each opened or closed so that the light waves reaching the output port via the gates which are open are selected according to the input ports which received them and according to their wavelength. The guide system is situated only between the optical gates and the output port and includes a wavelength separation system assigning some of the paths to the light waves according to their wavelength. The selector has applications in fiber optic telecommunication networks.

Abstract: An all-optical clock recovery system for recovering the clock from a received optical signal with a short response time and without patterning effects includes a first optical clock recovery device adapted to supply a first optical clock signal in response to the received optical signal and a second optical clock recovery device adapted to supply a second optical clock signal in response to the first optical clock signal. Applications include regenerating optical packets in asynchronous optical packet-switched telecommunication networks.

Abstract: A device for determining level values in data flows comprising different level values, is characterized by means for performing the following steps: 1.) detecting the change between different part-data flows or packets, 2.) starting an integration of the next part-data flow, 3.) holding the output value of the integration device, 4.) deriving a level value from the output value of the integration device. Advantages of the invention are short building-up time and thus a better use of the individual channels, especially optical channels.

Abstract: In order to be able to use a semiconductor light amplifier of conventional type and operating under gain saturation conditions while nevertheless providing constant gain for an optical signal to be amplified, the device comprises means for producing a compensation light wave and coupling means for injecting the optical signal to be amplified and the compensation light wave into the amplifier. The compensation light wave presents amplitude modulation such that when combined with the optical signal to be amplified the overall amplitude modulation is eliminated or at least attenuated. The device is applicable to optical transmission systems operating at a single wavelength or with wavelength division multiplexing.