Abstract: A semiconductor laser source wherein a waveguide in which a filter is produced is made of a material that is less sensitive to temperature. The laser source also includes a tuning device able to shift the possible resonant wavelengths ??Rj of a Fabry-Pérot optical cavity in response to an electrical controlling signal, a sensor able to measure a physical quantity representative of the difference between a central wavelength ?Cf of the filter and one of the possible wavelengths ?Rj, and an electronic circuit able to generate, depending on the physical quantity measured by the sensor, the electrical signal controlling the tuning device in order to keep one wavelength ?Rj at the centre of each passband of the filter that selects an emission wavelength ?Li of the laser source.

Abstract: A wavelength tunable laser emission device (1) comprises: a first waveguide (31) comprising an optical amplification means for producing a stimulated light emission, the first waveguide extending in a longitudinal direction of the emission device, a second waveguide (5) made of silicon on silicon dioxide and disposed parallel to the first waveguide spaced from the first waveguide in a vertical direction of the emission device so as to allow the existence of a hybrid optical mode coupled at one and the same time to the second waveguide and to the first waveguide, the second waveguide comprising a distributed reflector (9) along the second waveguide, the second waveguide comprising transverse zones (11, 12, 13, 14) doped differently so as to form a polar junction oriented in a transverse direction of the emission device. Electrodes (15, 16) coupled to the doped transverse zones modify an effective index seen by the hybrid optical mode.

Abstract: The invention relates to environmental characterization on the basis of an Ultra Wide Band (UWB) radiofrequency communication network. Pulses are emitted and the waveform received is compared with predicted waveforms corresponding to well determined interactions between the wave and its environment. The comparison is done by searching for maximum temporal correlation. The interactions can be notably reflections of the wave on walls or obstacles. The deformations are very dependent on the nature of the materials and directions in which the pulses are emitted and received. If predicted waveforms are stored for various pairs of direction of emission and of reception, it is possible through these correlation operations to find where a wall which gave rise to a reflection is situated.

Abstract: A receiver for transmission and parallel interference has multiple access interference suppression stages having K channels, each comprising a correlation device corresponding to a particular pseudorandom sequence and interference generation and suppression device. Each stage delivers to the following stage signals at least partly freed from multiple access interferences. A decision stage receives the signals from the channels of the preceding suppression stage. Each decision stage has a correlation device corresponding to one of the pseudorandom sequences and decision device to deliver data. Devices for producing synchronization signals can control the interference suppression and the decision device. The devices producing the synchronization signals have components placed in the channels of the final stage.