Abstract: Disclosed is an injected laser including an optical amplifying medium arranged inside a triggered laser cavity, the optical amplifying medium having a spectral amplifying band. The injected laser includes an optical phase-modulation device, arranged between the injection source and the laser cavity, the optical phase-modulation device being configured to periodically modulate as a function of time a phase of the monochromatic continuous laser radiation at a modulation frequency equal to a natural integer multiple of the free spectral range of the laser cavity, so that the phase-modulated injection source generates a polychromatic injection radiation.

Abstract: Disclosed is an injected laser including an optical amplifying medium arranged inside a triggered laser cavity, the optical amplifying medium having a spectral amplifying band. The injected laser includes an optical phase-modulation device, arranged between the injection source and the laser cavity, the optical phase-modulation device being configured to periodically modulate as a function of time a phase of the monochromatic continuous laser radiation at a modulation frequency equal to a natural integer multiple of the free spectral range of the laser cavity, so that the phase-modulated injection source generates a polychromatic injection radiation.

Abstract: A device for reducing time distortion generated in light pulses by an optical frequency converter including at least one nonlinear optical component (4) having a nonlinear optical susceptibility ? of about 2 or 3, the converter being capable of receiving at least one incident pulse light beam (2), the incident light pulses having a duration ?t0, an optical frequency ?0±??0 and an intensity I0(t), and of generating, by frequency conversion, at least one output pulse beam (3), the output light pulses having a duration ?t1, an optical frequency ?1±??1 different from ?0±??0, and an intensity I1(t). The time distortion-reducing device includes a pre-compensation linear time filter (5) provided on the path of the incident beam (2), and capable of reducing the intensity time distortions generated in the frequency-converted output light pulses to at least one pre-compensation intensity Icomp.

Abstract: A method for spreading a spectrum of a narrowband signal, e.g. a monochromatic optical signal or a radiofrequency carrier. The method uses a phase modulation using a modulation signal that includes a plurality of sinusoidal components, the plurality including a component at a fundamental frequency and at least one component at a frequency that is a harmonic of the fundamental frequency, the sinusoidal components being synchronous and affected with phases respectively equal to consecutive multiples of ?/2.

Abstract: Signal processing digital glasses, for protecting an operator's eyes against an annoying or hazardous light ray forming a light spot comprising at least one camera provided with a focusing optics, a power battery, at least one image reproduction screen capable of being provided in front of the operator's eyes, a unit for processing images received from the at least one camera and driving at least one image reproduction screen, a module for detecting and reproducing the light spot by a distinguishing mark on at least one viewing screen.

Abstract: A device for reducing time distortion generated in light pulses by an optical frequency converter including at least one nonlinear optical component (4) having a nonlinear optical susceptibility ? of about 2 or 3, the converter being capable of receiving at least one incident pulse light beam (2), the incident light pulses having a duration ?t0, an optical frequency ?0±??0 and an intensity I0(t), and of generating, by frequency conversion, at least one output pulse beam (3), the output light pulses having a duration ?t1, an optical frequency ?1±??1 different from ?0±??0, and an intensity I1(t). The time distortion-reducing device includes a pre-compensation linear time filter (5) provided on the path of the incident beam (2), and capable of reducing the intensity time distortions generated in the frequency-converted output light pulses to at least one pre-compensation intensity Icomp.

Abstract: A method for spreading a spectrum of a narrowband signal, e.g. a monochromatic optical signal or a radiofrequency carrier. The method uses a phase modulation using a modulation signal that includes a plurality of sinusoidal components, the plurality including a component at a fundamental frequency and at least one component at a frequency that is a harmonic of the fundamental frequency, the sinusoidal components being synchronous and affected with phases respectively equal to consecutive multiples of ?/2.

Abstract: The invention concerns a polarization-maintaining fiber-optic transmission system. The invention concerns a fiber-optic transmission system comprising at least one polarization maintaining fiber coupling an input device to an output device. The fiber comprises at least a first (F1) and a second (F2) polarization maintaining fiber section having each a slow propagation axis and a fast propagation axis. One end of the first fiber section is coupled to one end of the second fiber section such that the slow propagation axis of the first fiber section coincides with the fast propagation axis of the second fiber section and inversely. The invention is applicable in particular to lasers.

Abstract: To optimize the resources of an optical transmission network using wavelength division multiplexing, assigning carrier frequencies to signals to be transmitted consists in associating N sets of optical frequencies of the comb with N respective ranges of consecutive error rate values, each of the sets comprising frequencies generating a mean error rate in the associated range, defining a measured signal transmission constraint level that is a function of the transmission constraint parameter(s) and may take N distinct values referred to as constraint values, associating the N constraint values in increasing order respectively with the N sets of frequencies in decreasing order of the error rate values of the associated N ranges, assigning any signal to be transmitted a constraint value obtained by applying the measurement, and assigning the signal to be transmitted a carrier frequency belonging to one of the sets of frequencies that is associated with a constraint value at least equal to the constraint value as

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: The invention relates to a reconfigurable optical switching system for selectively coupling one or more frequencies of first and second input wavelength division multiplex signals (WDM1, WDM2) consisting of N channels to first and second output ports (O1, O2). The invention also relates to a variable and reconfigurable optical delay circuit comprising said optical switching system associated with an optical delay loop. The input frequency division multiplex optical spectra (WDM1, WDM2) are therefore divided by a first demultiplexer (Demux) to a plurality of interleaved stages of optical switches (D, C, A and B) which selectively feed a plurality of input ports (Mi) of a multiplexer (Mux), which then uses its routing properties to implement in particular the complex reconfigurable multiple 2×2 frequency switching function.

Abstract: The present invention relates to an optical communication network and to a network element for use in such a network. The network element comprises a plurality of receivers (70-76) for receiving optical communication signals, a plurality of transmitters (54-62, 82-86) for transmitting optical communication signals, and a plurality of network connections, each network connection having an individual signal impairment characteristic. The pluralities of receivers (70-76) and transmitters (54-62, 82-86) are adapted to employ a plurality of different modulation schemes (64, 66). Furthermore, the pluralities of receivers (70-76) and transmitters (54-62, 82-86) are assigned to the network connections as a function of the individual signal impairment characteristics.

Abstract: The invention relates to a time division and wavelength division multiplex optical switching node for use in an optical communications network (2), which node combines a set of time division multiplex packets (8-1, 8-2, . . . , 8-i) into a wavelength division multiplex packet (18) to form a composite wavelength division multiplex packet, in particular by conferring on each time division multiplex packet (8-1, 8-2, . . . , 8-I) a respective appropriate multiplexing wavelength (?1, ?2, . . . , ?i), for example a wavelength specific to each time division multiplex packet. The invention has applications in high bit rate optical networks in particular, in which it offers versatility and transparent use of the different multiplexing modes.

Abstract: A decision system for a modulated electrical signal delivered by a converter in response to a received modulated optical signal compares the amplitude of the electrical signal to a reference level, measures an average amplitude of the electrical signal, and generates the reference level as a function of the result of such measurements so that the “reference level/average amplitude” ratio can be adjusted to a predetermined constant value different from 1. Applications include receivers for optical packet transmission systems.

Abstract: A selective frequency extractor is disclosed which forwards one or more selected frequencies of a wavelength division multiplex input signal consisting of N channels to one output port and all the other frequencies to another output port. A reconfigurable frequency add and drop multiplexer is also disclosed. The input signal is divided up by a first demultiplexer and routed to a plurality of interleaved stages of optical switches for selectively feeding a plurality of input ports of a multiplexer, whose routing properties are then used for extracting one or more frequencies from the input signal or for reconfigurable frequency add and drop multiplexing.

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: The present invention relates to an optical cross-connector (1000) of multi-granular architecture comprising a first switching stage (100) for switching composite digital optical signals, the switching stage comprising a first optical switching matrix (1 to 4), wavelength band demultiplexing and multiplexer means (10, 20; 10?, 20?), a second switching stage (200) for switching digital optical signals and comprising a second switching matrix (5), wavelength demultiplexing and multiplexer means (61 to 64; 61? to 64?), redirection outlet ports (11? to 42?) of the first matrix being coupled to direction inlet ports of the second matrix. The optical first matrix comprises a series of independent optical switching sub-matrices (1 to 4) disposed in parallel.

Abstract: The routes for transmitting optical signals between the nodes (N1-N6) of a transparent network are selected according to the estimated error rate (ERe) values presented by the signals received after being transmitted along these routes. To limit the number of measurements to be made before the network is commissioned, a function (G) relating to the parameters characteristic of the network's optical links is used. This function is an interpolation function providing, for each set (QoT) of parameters associated with a given route, a corresponding estimated error rate (ERe) value. To evaluate the accuracy of the interpolation, during the network's operation, error rate measurements are performed, relating to signals effectively transmitted along given routes, and these measurements serve either to readjust the margin of uncertainty to be applied to exploit the estimated error rates (ERe), or to modify the function (G) to improve its interpolation accuracy.

Abstract: The present invention relates to a space cross-connect unit (Z) with N input ports (Ei) and P output ports (Si) more particularly suitable for packet-switched optical communications networks. The cross-connect unit comprises a broadcast stage comprising at most N signal dividers (Ai) each having an input and C outputs where C is an integer factor of P less than P, each input being connected to one of the N input ports (Ei) so that each of the N dividers (Ai) divides a signal received at one of the N input ports (Ei) into C signals at the C outputs, and a space switching stage comprising at most C space switching modules (Bi); each of the C modules (Bi) has N inputs and P/C outputs, the N inputs are connected to N outputs of the broadcast stage, each of the N outputs comes from a different divider (Ai), and each of the P/C outputs of the C modules (Bi) is connected to a respective one of said P output ports (Si).

Abstract: The optical switching device (100) includes: an optical switching matrix (1) including: input ports (A, B), output ports (a, b), switching means (3, 3′) between the input ports (A, B) and the output ports (a, b), and control means (2) for the switching matrix (1),  and optical paths are defined between the input ports (A, B) and the output ports (a, b) so that data entering via one of the input ports (A, B) is switched by the matrix (1) to exit at one of the output ports (a, b). The device is characterized in that the control means (2) include at least one configuration table (14) in which are written authorized optical paths producing a transmission error rate lower than a predetermined value.