Abstract: This invention relates to an optical equalisation device (312) of at least one incident optical beam (40) separated in wavelength into several channels or spectral bands called demultiplexed optical beam, the device including at least two independently controllable cells (420, 430, 440) each comprising spatial phase modulation means and means of scattering the incident optical beam(s). The device is adapted such that at least one of the demultiplexed beams (312) simultaneously and approximately illuminates at least two of the cells (420, 430, 440). The invention also relates to a corresponding system.

Abstract: The invention relates to an interferometric system (2) for selection of spectral components of an incident optical beam as a function of their wavelength, comprising: means (42) of transforming the said incident optical beam into two spatially demultiplexed beams; means (43) of shifting the phase of at least one of the said spatially demultiplexed beams, the phase shift being applied spatially so as to produce two so-called phase shifted beams, the phase of at least one of their components being shifted as a function of its wavelength; means (44, 42) of recombining the said phase shifted beams adapted to produce a first and a second output beam, each of the said output beams being multiplexed in wavelength and comprising components of the said phase shifted beams, selected as a function of a first and a second phase shift respectively.

Abstract: The invention relates to a dynamic spectral equaliser comprising: means of demultiplexing an incident beam with at least two multiplexed wavelengths, comprising at least one first dispersive optical element, so as to form a spatial multiplex of the said at least two wavelengths; means of attenuating the spectral power associated with at least one wavelength of the said spatial multiplex, comprising at least one programmable semi-transparent holographic mirror, so as to form an equalised spatial multiplex; means of multiplexing the said equalised spatial multiplex, comprising at least one second dispersive optical element, so as to form an equalised beam with at least two multiplexed wavelengths.

Abstract: The invention concerns a device for controlling the polarization of a signal transported, by optical fiber, in the form of a luminous beam. According to the invention, this device comprises: a cell formed by two substrate plates essentially parallel to one another and between which is confined a contents comprising a polymer in which droplets of liquid crystal are dispersed; first application means, on at least part of the cell contents, of an electrical field more or less perpendicular to the direction of the spread of the luminous beam. so that, depending on whether the first electrical field is applied or not, at least part of the contents of the cell forms a birefringent or isotropic medium respectively.

Abstract: This invention relates to a device for spatial modulation of a light beam, comprising a Polymer Dispersed Liquid Crystal (PDLC) element, the said element comprising at least two areas that can be addressed independently of each other using a system with at least two electrodes.

Abstract: A spatial light modulator (SLM) is made up of a cell filled with a liquid crystal (LC) based substance. Latter has a variable scattering property with respect to an electric field present in the cell. By using a plurality of electrodes in the direct vicinity of said cell, it is then possible to build an electric field inside it which will permit advantageously to modulate a continuous spectrum from optical signals transmitted through said cell. The different pass bands present in said continuous spectrum while at least few of them comprise at least a respective different wavelength will have to be transmitted through said cell at different regions. Latter will correspond to different values of the amplitude of scattering such to be adapted to modulate the respective different pass bands. Such SLM is used to build a dynamic spectral equalizer. Latter contains a spectral dispersive element placed on an optical path of an incident light beam.

Abstract: A spatial light modulator (SLM) is made up of a cell filled with a liquid crystal (LC) based substance. Latter has a variable scattering property with respect to an electric field present in the cell. By using a plurality of electrodes in the direct vicinity of said cell, it is then possible to build an electric field inside it which will permit advantageously to modulate a continuous spectrum from optical signals transmitted through said cell. The different pass bands present in said continuous spectrum while at least few of them comprise at least a respective different wavelength will have to be transmitted through said cell at different regions. Latter will correspond to different values of the amplitude of scattering such to be adapted to modulate the respective different pass bands. Such SLM is used to build a dynamic spectral equalizer. Latter contains a spectral dispersive element placed on an optical path of an incident light beam.

Abstract: The modulator is formed by a smectic chiral ferroelectric C* liquid crystal cell (CL), crossed by the light signal which is transmitted by the said fibre. The cell (CL) is provided with transparent walls and transparent command electrodes (5 to 7). The liquid crystal (CL), used in half-wave mode, is of the SSFLC (surface stabilized ferroelectric liquid crystal) type, having a wide tile angle .theta., which is as close as possible to 45.degree., in such a way that the said modulator is insensitive to polarisation. The modulator may be connected to two parallel fibres (A2, A3; B2, B3), pertaining to the intermediary part of a Mach-Zehnder coupler between the two 3 dB couplers, and when it is provided in order to modulate the light signal transmitted by either one of the two fibres.

Abstract: Light diffraction device using reconfigurable spatial light modulators and the fractional Talbot effect. This device comprises two liquid crystal, electrically addressable spatial light modulators (M1, M2) on a semiconductor substrate and at least one polarizing beam splitter (2), the optical path between the modulators being equal to (2k+1) Z.sub.T /4.sup.n in which k and n are natural integers, n differing from zero, and Z.sub.T is the Talbot distance relative to a biperiodic hologram obtained by means of one of the modulators and at one of the periods equal to double the other, which makes it possible to obtain a reconfigurable hologram having four phase levels. Application to optical telecommunications.