Abstract: A method for running, on a processor in non-privileged mode, different computer programs P while, in a nominal mode, using privileged instructions including running a hypervisor program in privileged mode of the processor, the hypervisor program providing the computer programs P with services substantially equivalent to those available for running in privileged mode, source codes of the computer programs P being modified beforehand for replacing the privileged instructions with calls for services supplied by the hypervisor program, and the hypervisor program creates at least two privileged submodes organized into a hierarchy within the non-privileged mode and the processor includes only two operating modes.

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: The invention is also related to devices for a synchronization of data in an optical WDM transmission system, consisting of the following parts: A wavelength demultiplexer (1) for demultiplexing the incoming data stream in the synchronizer, delay lines (2) for the individual wavelength channels, a multiplexer (10), a modulator (3) modulated by a high frequency clock signal (5) and at least one photodetector (4) tapped to output line (B) where the photodetector (4) is connected to an electronic control circuit (6) which is connected to the findividual delay lines (2) for an automatic delay control.

Abstract: A monolithic integrated optical component includes a control transistor connected to an electro-optical component including an active waveguide and at least one input waveguide and one output waveguide. The transistor is a heterojunction bipolar transistor including at least one sub-collector layer that is common to a confinement layer of the electro-optical component. The active waveguide of the electro-optical component includes a widened structure under a contact area of the heterojunction bipolar transistor and having substantially the same surface area as the transistor.

Abstract: 1. Multi-mode Interferometric coupler comprising: a first amplifying part (2), a second transparent part (4) to guide radiation previously amplified in the first part.

Abstract: The invention concerns a method for read-addressing a site among a plurality of storage units using a coded address derived from an instruction. The method comprises the following steps: a) predicting (104) the storage unit corresponding to the site to be addressed; b) decoding (108) the address of the site to be addressed and determining (109) the storage unit to be addressed; c) managing (105) a potential read and rewrite conflict assuming that the predicted storage unit is the storage unit to be addressed; d) controlling (111) the addressing of the predicted storage unit at the end of the managing step (105); e) at the end of step b), determining (110) whether the storage unit to be addressed corresponds to the predicted storage unit; and f) if the storage unit to be addressed does not correspond to the predicted storage unit, managing (115) a possible read and rewrite conflict in the storage unit to be addressed and addressing the site of the storage unit to be addressed.

Abstract: 1.

Abstract: A Multi-mode Interferometric coupler comprising: a first amplifying part (2), a second transparent part (4) to guide radiation previously amplified in the first part.

Abstract: Optical device (1) for the differentiation of a first optical signal and an optical signal lagging behind the first, in which the differentiation is represented by a signal carried by a continuous wave passing through the two arms (5, 6) of an interferometer comprising media with an index that depends on the optical power passing through them. The delayed signal is the first signal fed back to one of the arms through a delay (7).

Abstract: The present invention is a device for converting an RZ signal into a NRZ signal which contains an optical bistable device (5), where an output level of this device passing from a low level to a high level when an input power level crosses in an upward direction a first threshold, and returning to a low level when an input level crosses in a downward direction a second threshold below the first, the output (7) of the bistable (5) carrying the NRZ signal, and a device (2) for converting the RZ signal into a control signal of an output logic level of the optical bistable device (5) receiving the RZ signal, and delivering the control signal of the optical bistable device (5), this signal having a level above the first threshold when the RZ signal passes to 1 and which becomes lower at the second threshold only if the RZ signal passes to 0 and stays there for more than one bit time.

Abstract: An optical device for the differentiation of a first optical signal and an optical signal lagging behind the first, in which the differentiation is represented by a signal carried by a continuous wave passing through the two arms of an interferometer including media with an index that depends on the optical power passing through them. The delayed signal is the first signal fed back to one of the arms through a delay.

Abstract: Converter of an NRZ signal with a bit duration T comprising an interferometric structure (10) with two arms (9, 11) equipped with a medium (13, 15) with an index that varies depending on the optical power passing through the said medium. The NRZ signal to be converted is input into each of the arms (9, 11). The output signal (7) from the structure is reinput through a means (16) introducing a delay of T/2 in one of the arms (11). The signal at the output (7) is then the NRZ signal converted to the RZ format.

Abstract: In a device for regenerating a wavelength-division multiplex optical signal, the optical signal to be regenerated comes from an optical fiber and is injected back into the same optical fiber or into another fiber. The device comprises at least one dispersive medium for receiving the wavelength-division multiplex signal and emitting a corresponding dispersed wave into a free space and a saturable absorber which receives the dispersed wave and transmits a corresponding regenerated wave.

Abstract: The present invention relates to a data processing system comprising a processor provided with two memory access units operating in parallel; two separate memories respectively associated with the two access units; and circuitry for, when the address of a datum to be written into a memory is in a predetermined address range, writing the datum into both memories at the same time at the same address.

Abstract: An optical signal regenerator includes a mechanism for reconstituting an optical signal carrier wave. The optical signal is thus regenerated on the same wavelength as the incoming carrier wave.

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 monolithic integrated optical component includes a control transistor connected to an electro-optical component including an active waveguide and at least one input waveguide and one output waveguide. The transistor is a heterojunction bipolar transistor including at least one sub-collector layer that is common to a confinement layer of the electro-optical component. The active waveguide of the electro-optical component includes a widened structure under a contact area of the heterojunction bipolar transistor and having substantially the same surface area as the transistor.

Abstract: The invention is also related to a devices for a synchronization of data in an optical WDM transmission system, consisting of the following parts: A wavelength demultiplexer (1) for demultiplexing the incoming data stream in the synchronizer, delay lines (2) for the individual wavelength channels, a multiplexer (10), a modulator (3) modulated by a high frequency clock signal (5) and at least one photodetector (4) tapped to output line (B) where the photodetector (4) is connected to an electronic control circuit (6) which is connected to the individual delay lines (2) for an automatically adaptation.

Abstract: A device (1) for converting an RZ signal into a NRZ signal comprising:

Abstract: Converter of an NRZ signal with a bit duration T comprising an interferometric structure (10) with two arms (9, 11) equipped with a medium (13, 15) with an index that varies depending on the optical power passing through the said medium. The NRZ signal to be converted is input into each of the arms (9, 11). The output signal (7) from the structure is reinput through a means (16) introducing a delay of T/2 in one of the arms (11).