Abstract: The invention concerns a rectangular response optical filter for partitioning a limited spectral interval in a light flux with large spectrum comprising: a preferably monomode input optical fiber having one end; an array-reflector assembly in Litmann-Metcalf configuration; a converging optical system collimating at whose focus is set the input fiber end; a converging focusing optical system set between the array and the reflector; one or several output fibers of the same type as the input fiber. At least one reflector is placed in the focal plane of the focusing optical system and has a limited dimension in the dispersion plane, the position and the limited dimension of the dispersion plane determining the partitioned spectral interval.

Abstract: The present invention relates to a continuously tuneable free space laser. An amplifying medium in free space is placed inside a Fabry-Perot cavity consisting of two reflectors. One of these two mirrors being partially translucent and makes up the output mirror of the laser. According to the invention, the output mirror is inserted into the core of a monomode optic fiber that constitutes an output optic fiber and a lens placed in the Fabry-Perot cavity. This ensures coupling in this fiber of the luminous fluxes transmitted by the amplifying medium and the second reflector is self-aligned.

Abstract: Laser source comprising a first active arm extending from a first end reflector up to a dispersing system grid and containing an amplifier medium that produces a first luminous beam. A second passive arm extends from the grid to a second end reflector, the grid generating a second beam by diffraction of the first beam, wherein the second end reflector closes the second passive arm and is partially reflecting to enable extraction of a luminous flux. An optical component produces, from the second beam, a third beam translated and antiparallel, to return to the grid which, by diffraction, forms a fourth beam translated and antiparallel to the first beam.

Abstract: A partially reflecting optical component (11) generating, from an incident beam (12), two secondary beams, one of them being reflected (13), the other one being transmitted (14). According to the invention, it comprises a first wholly reflecting planar face (15) and a second partially reflecting planar face (16), the second face being perpendicular to the first one, a third wholly reflecting planar face (17), the first and third faces being in the same plane, this component providing the unidimensional auto-alignment of the reflected beam (13) with the incident beam (12), the respectively transmitted and reflected beams being each formed with two half-beams having matching wave fronts. The invention also relates to an external cavity laser source comprising such a component as a unidimensional auto-aligned reflector.

Abstract: A wavelength tuneable laser source with an external cavity and utilizing an interferometer having a reciprocal output and a non-reciprocal output. The laser source includes an amplifier medium, a cavity comprising two reflectors and a source beam extraction system, a diffraction grating located in the cavity. At least one of the two reflectors are rotatable so as to tune a wavelength. The source beam extraction mechanism includes a beam splitter for splitting an input beam into first and second secondary beams. The first and second secondary beams are parallel to one another. The source beam extraction mechanism also includes a retro-reflecting mechanism for redirecting the first and second secondary beams toward the beam splitter. A non-reciprocal output beam is obtained from a reciprocal source beam using the interferometer.

Abstract: Multiwavelength laser source transmitting a luminous flux including as many amplifier wave-guides as potential transmission wavelengths, a collimation optic system for collimating the beams transmitted by the wave-guides, a network and a retroreflector making up the network, a dispersive retroreflecting device that defines with each wave-guide, an external resonating cavity, whereas each wave-guide has an inner face and an outer face with respect to its associated cavity. A Fabry-Perot interferometer with reduced fine adjustment is placed in the cavity between the collimation optic system and the network, whereby the interferometer is tilted with respect to the axis of the cavity and forms a little selective filter, whose variation law of the wavelength transmitted in relation to the angle of incidence is identical with that of the dispersive retroreflecting device.

Abstract: Optical reflector for receiving an input beam and transmitting a retro-reflected reciprocal output beam. The optical reflector includes a beam splitter for splitting the input beam into first and second secondary beams. The first and second secondary beams being parallel to one another. A reflecting system is also included for redirecting the first and second secondary beams toward the beam splitter. The reflecting system including a total reflector. The beam splitter and the reflecting system are self-aligned.

Abstract: A single dimension self-aligned retroreflecting optical system for wavelength filtering, comprising at least one wave-guide with one internal face in a focal plane of collimation optics generating a main collimated beam. A diffraction grating has parallel lines, the lines disperse, in collimated beams, the different wavelengths of the main beam in directions parallel to a dispersing plane, the dispersing plane being perpendicular to the lines of the grating. A reflector system generates self-alignment in a longitudinal plane perpendicular to the dispersing plane. The reflector system comprises a spherical lens and a single dimension self-aligned reflector arrangement, the dimension being parallel to the dispersing plane of the grating.

Abstract: The present invention relates to an optical fiber wavelength multiplexing or demultiplexing device comprising: An optical fiber wavelength multiplexing device comprising: an array of input single-mode fibers (101 to 105) designed for carrying light beams at different wavelengths (&lgr;1, &lgr;2, &lgr;2, . . .

Abstract: The invention relates to an external cavity, continuously tunable monomode laser source, comprising, in a resonant cavity, resonating at the emission wavelength &lgr;e, a retroreflecting wavelength dispersing device, arranged to produce a selectivity curve with a peak 80 s. According to the invention, additional fine-control means, enable, from the approximate continuous tunability position, to monitor the deviation &lgr;e-&lgr;s during the variation of the emission wavelength ke while preventing this deviation from reaching one of the limits causing mode hopping. Such a configuration enables to avoid imperfections usually associated with mechanical adjustment and to guarantee continuity of the wavelength variation and to compensate for the latter as long as its fluctuations remain smaller than approx. &Dgr;&lgr;e/2 where &Dgr;&lgr;e is the distance between two successive resonance modes of the cavity.

Abstract: This invention relates to an optical reflector receiving an input beam (22) and transmitting a retroreflected reciprocal output beam (28), comprising a beam splitter (20) giving a first secondary beam (27) and a second secondary beam (28), parallel to one another as well as retroreflecting means (21) each redirecting secondary beams toward the beam splitter and forming a Sagnac interferometer,.

Abstract: Optical reflector for receiving an input beam and transmitting a retro-reflected reciprocal output beam. The optical reflector includes a beam splitter for splitting the input beam into first and second secondary beams. The first and second secondary beams being parallel to one another. A reflecting system is also included for redirecting the first and second secondary beams toward the beam splitter. The reflecting system including a total reflector. The beam splitter and the reflecting system are self-aligned.

Abstract: An optical wave-guide wavelength multiplexing device comprising: an array of input single-mode wave-guides designed for carrying light beams at different wavelengths (&lgr;1, &lgr;2, . . . , &lgr;n), an output single-mode wave-guide designed for carrying the whole set of such light beams, a dispersing system receiving light beams from the input wave-guides in an end plane and generating superimposed light beams designed for the output wave-guide in an output plane, a collimating lens which produces collimated beams from the input wave-guides whose respective central axes are converging to be superposed on the rear reflector of the dispersing system, a refracting prism located between the dispersing system and the collimating lens. A polarization splitter can also be placed between the output single-mode wave-guides array and the grating. The demultiplexer comprises the same elements, whereas the roles of the input/output wave-guides and planes are reversed.

Abstract: The present invention relates to an optical fiber wavelength multiplexing or demultiplexing device comprising.The multiplexer comprises input fibers (101 to 105) designed for carrying luminous beams at different wavelengths (.lambda.1, .lambda.2, . . . , .lambda.n), an output fiber (161) designed for carrying the whole set of such luminous beams, a dispersing system (107) receiving luminous beams from the input fibers (101 to 105) in an input plane and generating superimposed luminous beams designed for the output fiber (161) in an output plane.A converging lens array (171 to 175) is located in the input plane, whereas a lens corresponds to each input fiber and whereby the said input fiber is placed in the focal point of the said lens.The demultiplexer comprises the same elements, whereas the roles of the fibers and input/ouput planes are reversed.

Abstract: The invention relates to a broadband light source including an amplifying guide structure (1). The light source includes a device (45) of exciting the guide structure (1). The stimulated guide structure (1) emits light (7, 8) that accepts strong spatial coherence and weak time coherence. The light (7) is transmitted forwards (2) having a spontaneous emission spectrum. The light source also includes a rear mirror (5), reflecting only for a narrower range of wavelengths than the spontaneous emission spectrum and produces emission (E) forwards (2) with an emission spectrum controlled around an average wavelength. The rear mirror is inserted between the excitation means and the guide structure.

Abstract: The invention relates to an optical spectrum analyzer of an incident light beam (101) and a process for analyzing the corresponding spectrum. The spectrum analyzer comprises addressing means (1), a diffraction grating (2), a reflecting dihedron (3), a device (4) for adjusting the rotation of the reflecting dihedron and reception means (5). A polarization separator (11) divides the incident beam (101) into a first and second parallel secondary beam (102, 104), of linearly polarized light along the directions parallel to and perpendicular to the grooves in the grating respectively, and a .lambda./2 plate (12) placed on the path of the first secondary beam (102) applies a perpendicular polarization direction to this beam. The grating diffracts the secondary beams (103, 104) a first time, the reflecting dihedron exchanges their directions, the grating diffracts them a second time, the .lambda./2 plate applies a 90.degree.

Abstract: This invention relates to a singlemode laser source tunable in wavelength with a self-aligned external cavity, comprising: a resonant cavity having an output face that is partially reflecting (331) and a retroreflecting dispersive device (31, 39), defining a main collimating axis (351) and a secondary collimating axis (381), an amplifier wave guide (33) placed in position inside the resonant cavity. The retroreflecting dispersive device comprises a plane diffraction grating (31) having dispersion planes and an orthogonal reflecting dihedral (39) whose line of intersection (391) is parallel to the dispersion plane of the diffraction grating containing the collimating axes (351, 352).

Abstract: A process and an optical gyroscope are provided for measuring rotation speeds (S) about N axes. The light source and the photodetector are common. Controlled modulation phase differences .delta..PHI..sub.c,i COMPRISE biasing components .delta..PHI..sub.m,i (42, 45, 46) with a common modulation period T.sub.m and common amplitude. Since each half-period T.sub.m /2 is divided into N time intervals .delta.t.sub.i, a change in the sign of the biasing component .delta..PHI..sub.m,i associated with each interferometer I.sub.i is produced at the beginning of one and only one .delta.t.sub.i time interval. Sagnac phase shifts .delta..PHI..sub.s,i are obtained by sampling a signal on the N time intervals.

Abstract: An appliance for measuring polarization mode dispersion (PMD) of a waveguide (2) comprises a source (1, 6) of wide-band polarized light, an interferometer (5) capable of receiving a light beam (21) sent by the source (1, 6), a detector (3) capable of detecting the light beam (25) from the interferometer (5), and an electronic processing unit (4) connected to the detector (3), capable of extracting a value .tau. representative of the polarization mode dispersion of the waveguide (2). The interferometer (5) divides a measuring light beam (22) sent by the source (1) into two interference light beams (23, 24). The measuring appliance comprises at least one birefringent element (17) positioned on the interferometer (5), capable of producing an algebraic difference of relative phase shifts in each of the two interference light beams (23, 24) equal to .pi..

Abstract: This invention relates to a singlemode laser source tunable in wavelength with a self-aligned external cavity, comprising: a resonant cavity having an output face that is partially reflecting (331) and a retroreflecting dispersive device (31, 39), defining a main collimating axis (351) and a secondary collimating axis (381), an amplifier wave guide (33) placed in position inside the resonant cavity. The retroreflecting dispersive device comprises a plane diffraction grating (31) having dispersion planes and an orthogonal reflecting dihedral (39) whose line of intersection (391)is parallel to the dispersion plane of the diffraction grating containing the collimating axes (351, 352).