Patents by Inventor Richard L. Lachance
Richard L. Lachance has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7123795Abstract: A method for aligning the spectral responses of two comb-like optical filters is provided. This method does not necessitate the use of spectrally-resolved equipment, as it uses the optical power correlation profile of a broadband light signal representative of the combined spectral responses of the two filters. In one embodiment, the power correlation profile is compared to a pre-stored profile. A tuning method for tuning two filters using this alignment method is also provided. The two filters are first relaxed to an unstretched position, and the second filter is stretched and aligned with the first. The first filter is also stretched and aligned with the other. Both filters are then stretched at a calibrated value.Type: GrantFiled: October 25, 2005Date of Patent: October 17, 2006Assignee: Teraxion Inc.Inventors: Simon Savard, Richard L. Lachance, Alain Mailloux
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Patent number: 6937793Abstract: A tunable dispersion compensator for the compensation of the chromatic dispersion experienced by a single-channel or multi-channel light signal. The compensator includes a plurality of optical structures such as chirped Bragg gratings or combinations thereof, each having a characteristic dispersion profile. An optical coupling arrangement successively propagates the light signal in each of these structures, so that it accumulates the dispersion compensation effect of each. A tuning device jointly tunes the dispersion profile of each optical structure by applying a same tuning force thereto, preferably a temperature gradient.Type: GrantFiled: March 17, 2003Date of Patent: August 30, 2005Assignee: Teraxion Inc.Inventors: Sylviane Lelievre, Richard L. Lachance, Yves Painchaud
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Patent number: 6907164Abstract: An athermally packaged optical fiber device, such as a Bragg grating, is provided. The device includes a hollow structure, and a free and a threaded member projecting in the hollow structure from both ends. The optical fiber is mounted in tension inside the hollow structure through longitudinal fiber-receiving bores in both members, and has an anchor point affixed to each member with the grating therebetween. The anchor point of the threaded member is provided outside of the hollow structure, making the device more compact. The free and threaded members are rotatable together to adjust the resonant wavelength of the grating, and a nut may be provided to allow a fine-tuning. The hollow structure, free member and threaded member have a coefficient of thermal expansion selected so that they together compensate for the temperature dependency of the Bragg wavelength.Type: GrantFiled: September 12, 2001Date of Patent: June 14, 2005Assignee: Teraxion, Inc.Inventors: Richard L. Lachance, André Vo Van, Michel Morin, Martin Guy, Martin Pelletier
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Patent number: 6859583Abstract: A fine-tuning assembly for an optical grating in an optical fiber is provided. The fiber is mounted under tension in a hollow structure which has a sliding member longitudinally slideable therein. The fiber is attached to both the sliding member and hollow structure. A slanted passage is provided in the sliding member, forming a small angle with the transversal, and a wedge member is slideably inserted in this passage. To fine-tune the spectral response of the grating, the wedge member is transversally displaced without any longitudinal displacement, preferably by the action of screws, thereby pushing on its walls to longitudinally slide the sliding member and adjust the tension in the fiber.Type: GrantFiled: February 22, 2002Date of Patent: February 22, 2005Assignee: Teraxion Inc.Inventors: Richard L. Lachance, Andre Vovan
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Patent number: 6842567Abstract: The present invention discloses practical and power efficient assemblies for applying a temperature gradient to a fiber Bragg grating. An application of such assemblies is, for example, the active tuning of the chromatic dispersion of the grating. The temperature gradient is produced in a heat conductive element, with which the FBG is in continuous thermal contact, by elements controlling the temperature of the ends of the heat conductive element, thereby applying the temperature gradient to the FBG. A first preferred embodiment includes a heat recirculation member allowing the recirculation of heat between the two ends of the heat conductive elongated element, thereby providing a rapid and dynamical tuning of the temperature gradient with a minimal heat loss. A second embodiment provides isolation from the surrounding environment in order to decouple the desired temperature gradient from ambient temperature fluctuations, thereby improving the control of the optical response of a fiber grating.Type: GrantFiled: February 6, 2003Date of Patent: January 11, 2005Assignee: Teraxion Inc.Inventors: Richard L. Lachance, Philippe Pépin, Tristan Rüthers, François Pelletier
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Publication number: 20040017972Abstract: A tunable dispersion compensator for the compensation of the chromatic dispersion experienced by a single-channel or multi-channel light signal. The compensator includes a plurality of optical structures such as chirped Bragg gratings or combinations thereof, each having a characteristic dispersion profile. An optical coupling arrangement successively propagates the light signal in each of these structures, so that it accumulates the dispersion compensation effect of each. A tuning device jointly tunes the dispersion profile of each optical structure by applying a same tuning force thereto, preferably a temperature gradient.Type: ApplicationFiled: March 17, 2003Publication date: January 29, 2004Applicant: Teraxion Inc.Inventors: Sylviane Lelievre, Richard L. Lachance, Yves Painchaud
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Publication number: 20030198434Abstract: The present invention discloses practical and power efficient assemblies for applying a temperature gradient to a fiber Bragg grating. An application of such assemblies is, for example, the active tuning of the chromatic dispersion of the grating. The temperature gradient is produced in a heat conductive element, with which the FBG is in continuous thermal contact, by elements controlling the temperature of the ends of the heat conductive element, thereby applying the temperature gradient to the FBG. A first preferred embodiment includes a heat recirculation member allowing the recirculation of heat between the two ends of the heat conductive elongated element, thereby providing a rapid and dynamical tuning of the temperature gradient with a minimal heat loss. A second embodiment provides isolation from the surrounding environment in order to decouple the desired temperature gradient from ambient temperature fluctuations, thereby improving the control of the optical response of a fiber grating.Type: ApplicationFiled: February 6, 2003Publication date: October 23, 2003Applicant: TERAXION INC.Inventors: Richard L. Lachance, Philippe Pepin, Tristan Ruthers, Francois Pelletier
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Publication number: 20020150335Abstract: A fine-tuning assembly for an optical grating in an optical fiber is provided. The fiber is mounted under tension in a hollow structure which has a sliding member longitudinally slideable therein. The fiber is attached to both the sliding member and hollow structure. A slanted passage is provided in the sliding member, forming a small angle with the transversal, and a wedge member is slideably inserted in this passage. To fine-tune the spectral response of the grating, the wedge member is transversally displaced without any longitudinal displacement, preferably by the action of screws, thereby pushing on its walls to longitudinally slide the sliding member and adjust the tension in the fiber.Type: ApplicationFiled: February 22, 2002Publication date: October 17, 2002Applicant: Teraxion Inc.Inventors: Richard L. Lachance, Andre Vovan
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Publication number: 20020141700Abstract: An athermally packaged optical fiber device, such as a Bragg grating, is provided. The device includes a hollow structure, and a free and a threaded member projecting in the hollow structure from both ends. The optical fiber is mounted in tension inside the hollow structure through longitudinal fiber-receiving bores in both members, and has an anchor point affixed to each member with the grating therebetween. The anchor point of the threaded member is provided outside of the hollow structure, making the device more compact. The free and threaded members are rotatable together to adjust the resonant wavelength of the grating, and a nut may be provided to allow a fine-tuning. The hollow structure, free member and threaded member have a coefficient of thermal expansion selected so that they together compensate for the temperature dependency of the Bragg wavelength.Type: ApplicationFiled: September 12, 2001Publication date: October 3, 2002Applicant: Teraxion Inc.Inventors: Richard L. Lachance, Andre Vo Van, Michel Morin, Martin Guy, Martin Pelletier
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Patent number: 5255283Abstract: A process for making a custom phase-conjugated circular mirror to be used in a laser resonator that will suit specifications of a user is provided. The mirror reverses wavefront of one particular input beam .PSI..sub.o (x) determined by the user, the input beam .PSI..sub.o (x) having a given wavelength, the laser resonator including the mirror and an output coupler cooperating with the mirror and separated therefrom by a laser gain medium, the mirror being at a distance L from the output coupler. The process comprises steps of (a) determining the input beam .PSI..sub.o (x) that will suit need of the user; (b) calculating equation of .PSI..sub.L (x) which is a value of the input beam .PSI..sub.o (x) that is propagated through said laser gain medium at distance L; (c) calculating phase .PHI..sub.o (x) of the input beam, which is a phase of the input beam .PSI..sub.o (x) at distance L, the phase .PHI..sub.Type: GrantFiled: June 30, 1992Date of Patent: October 19, 1993Assignee: Universite LavalInventors: Pierre-Andre Belanger, Claude Pare, Richard L. Lachance, Richard Van Neste