Photonetics

Photonetics S.a.

U.S. Philips Corporation

Cabinet Harle & Phelip

Nettest Photonics S.a.s.

Phononetics, S.a.

Photonectics

Philippe Martin

Herve Lefevre

Bernard Laloux

Philippe Graindorge

Bertrand Merigot

Herv&eacute; Lefevre

Yves Mathieu

Thierry Bonnet

Pascal Simonpietri

Gilles Le Boudec

Denis Mangeot

Laurent Disdier

Thierry Gaiffe

Herv&euml; Lefevre

Joel Morisse

Herve Lefervre

Edouard Taufflieb

Olivier Duthuit

Sophie Bourzeix

Herve J Arditty

Francois X Desforge

Daniel Gatti

Phillipe Graindorge

An optical device for wavelength interleaving or dissociation includes a device for coupling a luminous flux generated by a source in an input fiber, a circulator linked to the input fiber and to an output fiber forming a first output gate of the optical device, and a polarisation beam splitter receiving the luminous flux coming out of the circulator and separating it into two components. A device is provided for transferring the luminous flux from one output to the other, a birefringent medium is interposed on the optical path and a fiber forms a second output of the optical device.

Optical device for wavelength interleaving or dissociation and optical switch

This invention relates to an optic multiplexer or demultiplexer comprising an inlet optic fibre, a wavelength dispersive optic system, outlet optic fibres and a two-wave interferometer. The two-wave interferometer has a spectral response exhibiting minima at twice the frequency of the response of the multiplexer or demultiplexer.

Optic fibre multiplexer-demultiplexer with flattened response

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.

Multiwavelength source

Optical fiber wavelength, multiplexer and demultiplexer

Continuously wavelength-tunable monomode laser source

Optical wave-guide wavelength multiplexer and demultiplexer

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.

Optical fiber wavelength multiplexer and demutiplexer

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. rotation to the polarization state of the second secondary beam (110) and the separator recombines the secondary beams (109, 111) into a single main beam (112) returned to reception means.

Optical spectrum analyzer and process for analyzing the corresponding

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).

Singlemode laser source tunable in wavelength with a self-aligned

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.

Process for measuring rotation speeds about several axes, and a

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..

Appliance for measuring polarization mode dispersion and corresponding

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).

The invention concerns an optical fiber measuring device, for example a gyrometer. The working of this device is independent of possible variations in the spectrum of the source. It includes a narrow, stable spectral filter which separates the incident flux. The modulation chain is slaved by a first detector (3). A second detector (23) receives the filtered flux. Its response is processed by a device (219) which supplies a signal that is a function of the spectrum of the light source (1).

Optical fiber measuring device using phase difference

The invention relates to a fiber optic measuring device in which the variation in a measured parameter engenders a phase difference between two waves. It comprises a SAGNAC ring interferometer (2) in which two counter-propagating waves propagate; a polarization splitter (6) spatially splits the two polarizations which will propagate in the interferometer (2), interferometer (2) comprises a polarization conserving birefringent fiber (7) having two ends having neutral birefringence axes, each of the ends of the polarization conserving fiber (7) being connected to one of the gates (6b) and (6c) of the polarization splitter (6). It comprises a birefringent component, placed ahead of the polarization splitter (6) and introducing a path difference greater than the coherence length of the source (1) between the two polarized waves.

Fibre optic measuring device, rate gyro, stabilization system and

A fiber optic measuring device can be used, for example, as a rate gyro. Variation in a measured parameters engenders a phase difference between two waves. The measuring device includes a light source 1, a SAGNAC ring interferometer 2, a detector 3, a phase modulator 4, and a electronic unit 7. The electronic unit 7 includes a processing system 9 which furnishes a signal that is a function of the measured parameter and an electronic sub-unit 12 for controlling the phase modulator 4. The control signal for the modulator is a superposition of a first, periodic gating, bias signal .PHI..sub.b (t) with period 2.tau. and amplitude .PHI..sub.bm, and of a second, staircase, negative-feedback signal .PHI..sub.m (t) synchronized with .PHI..sub.b (t), each step of which has a duration equal to .tau. or to one of its sub-multiples, and an amplitude .PHI..sub.s, which is a function of the value of the measured parameter and which falls back to zero when its amplitude exceeds a predetermined value .PHI..sub.mm . .PHI..sub.bm and .PHI..sub.mm are slaved to 2.PHI..sub.bm +.PHI..sub.mm =2n.pi. (where n is an integer). The response to the singular phase shift introduced during the fall-back of the negative-feedback signal is for this slaving and hence is used to keep the gain of the modulation chain constant.

Growing community of inventors

Pontchartrain, France

Philippe Martin