Patents by Inventor Michel Têtu

Michel Têtu 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).

  • Patent number: 7471710
    Abstract: A narrow linewidth semiconductor laser device has a semiconductor laser and a low noise current source operatively connected to the laser with the current source being adapted to prevent degradation of the laser's frequency noise spectrum. An optical frequency discriminator provides an error signal representative of the laser's optical frequency and a control circuit has a feedback network that provides a frequency feedback signal that is adapted to the frequency noise spectrum of the frequency discriminator and to the laser's frequency noise spectrum and tuning response. The control circuit also has a sequencer to automatically enable frequency locking of the laser on the frequency reference of the optical frequency discriminator. An enclosure encloses the frequency discriminator to isolate the frequency discriminator from external perturbations.
    Type: Grant
    Filed: December 23, 2005
    Date of Patent: December 30, 2008
    Assignee: Teraxion Inc.
    Inventors: Jean-François Cliche, Michel Tetu, François Baribeau, Stéphane Blin, Martin Guy
  • Publication number: 20060159135
    Abstract: There is provided a narrow linewidth semiconductor laser device comprising a semiconductor laser and a low noise current source operatively connected to the laser for supplying current thereto, the current source being particularly adapted to prevent a significant degradation of the frequency noise spectrum of the laser. The laser device also has an optical frequency discriminator providing an error signal representative of the optical frequency of the laser. The laser device also has control means having a feedback network for providing a frequency feedback signal. The feedback network is particularly adapted to the frequency noise spectrum of the frequency discriminator, the frequency noise spectrum of the laser and the tuning response of the laser. The control means is also provided with sequencing means for allowing to automatically enable frequency locking of the laser on the frequency reference of the optical frequency discriminator.
    Type: Application
    Filed: December 23, 2005
    Publication date: July 20, 2006
    Applicant: Teraxion Inc.
    Inventors: Jean-Francois Cliche, Michel Tetu, Francois Baribeau, Stephane Blin, Martin Guy
  • Patent number: 6953487
    Abstract: A metallic gas cell including a metallic casing having an input open end and an output open end, and a opening located therebetween. The metallic gas cell also includes an input and an output optical modules, each being respectively hermetically attached to one of the corresponding open ends. The metallic gas cell includes sealing means for sealing each of the optical modules in one of the corresponding open ends, thereby defining an airtight cavity in the casing when the opening is sealed. The metallic gas cell also includes an optical energy absorbing gas being enclosed within the cavity. The metallic gas cell is advantageously modular for allowing the use of various input or output modules such as windows, lenses, lasers, photodetectors, and fiber collimators. The gas cell also allow multi-cavity gas cell that that use a minimum number of components and cells to be obtained. Moreover, by its specific construction, the present gas cell prevents alignment issues.
    Type: Grant
    Filed: March 18, 2003
    Date of Patent: October 11, 2005
    Assignee: Teraxion Inc.
    Inventors: Jean-François Cliche, Michel Têtu, Nicolas Côte, Sébastien Tranchart
  • Patent number: 6865007
    Abstract: There is provided a complex frequency response filter providing a frequency response having a desired shape. A first complex frequency response filter includes a first and a second reflecting surfaces defining a resonant cavity therebetween. Each of the reflecting surfaces respectively has a predetermined surface finish providing a given reflectivity, therefore providing resonances with a predetermined shaped frequency response of a predetermined amplitude and of a predetermined periodicity. Those frequency responses can then be summed to generate an arbitrarily complex spectral response. In another embodiment, the complex frequency response filter includes a transmission medium and a first and a second reflecting surfaces defining a resonant cavity therebetween.
    Type: Grant
    Filed: March 18, 2003
    Date of Patent: March 8, 2005
    Assignee: Dicos Technologies Inc.
    Inventors: Jean-François Cliche, Michel Têtu, Christine Latrasse, Alain Zarka
  • Patent number: 6717967
    Abstract: A method and a system for filtering a user light beam using a periodic filter having a frequency response stabilized at an absolutely calibrated value are provided. A primary light beam is generated by a tunable laser source and portions thereof are filtered by an absolute reference filter and the periodic filter. First the frequency of the laser source is automatically locked on the absolute reference filter, and then the frequency response of the periodic filter is locked relative to the frequency of the laser source. The frequency response of the periodic filter is therefore continuously maintained at the proper calibration. User input and output are provided to pass the user light beam through the stabilized periodic filter independently of the filter stabilization process. A broadband absolutely calibrated optical source and a method for absolutely calibrating an optical spectrum analysis device are also provided.
    Type: Grant
    Filed: November 13, 2002
    Date of Patent: April 6, 2004
    Assignee: Dicos Technologies Inc.
    Inventors: Jean-François Cliche, Michel Têtu, Christine Latrasse, Alain Zarka
  • Publication number: 20040047041
    Abstract: There is provided a complex frequency response filter providing a frequency response having a desired shape. A first complex frequency response filter includes a first and a second reflecting surfaces defining a resonant cavity therebetween. Each of the reflecting surfaces respectively has a predetermined surface finish providing a given reflectivity, therefore providing resonances with a predetermined shaped frequency response of a predetermined amplitude and of a predetermined periodicity. Those frequency responses can then be summed to generate an arbitrarily complex spectral response.
    Type: Application
    Filed: March 18, 2003
    Publication date: March 11, 2004
    Inventors: Jean-Francois Cliche, Michel Tetu, Christine Latrasse, Alain Zarka
  • Publication number: 20040004720
    Abstract: A metallic gas cell including a metallic casing having an input open end and an output open end, and a opening located therebetween. The metallic gas cell also includes an input and an output optical modules, each being respectively hermetically attached to one of the corresponding open ends. The metallic gas cell includes sealing means for sealing each of the optical modules in one of the corresponding open ends, thereby defining an airtight cavity in the casing when the opening is sealed. The metallic gas cell also includes an optical energy absorbing gas being enclosed within the cavity. The metallic gas cell is advantageously modular for allowing the use of various input or output modules such as windows, lenses, lasers, photodetectors, and fiber collimators. The gas cell also allow multi-cavity gas cell that that use a minimum number of components and cells to be obtained. Moreover, by its specific construction, the present gas cell prevents alignment issues.
    Type: Application
    Filed: March 18, 2003
    Publication date: January 8, 2004
    Inventors: Jean-Francois Cliche, Michel Tetu, Nicolas Cote, Sebastien Tranchart
  • Publication number: 20030174743
    Abstract: A method and a system for filtering a user light beam using a periodic filter having a frequency response stabilized at an absolutely calibrated value are provided. A primary light beam having a tunable frequency is generated by a tunable laser source, and then split into first and second beams respectively sent to an absolute reference filter and the periodic filter. The signal from the absolute reference filter is first used for automatically locking the frequency of the tunable laser source relative to a selected absorption features of the absolute reference filter. Once the laser source is locked, the frequency response of the periodic filter is stabilized using the filtered second beam, with a selected spectral feature of the periodic filter frequency response being locked relative to the frequency of the tunable laser source. The frequency response of periodic filter is therefore continuously maintained at the proper calibration.
    Type: Application
    Filed: November 13, 2002
    Publication date: September 18, 2003
    Applicant: DICOS TECHNOLOGIES INC.
    Inventors: Jean-Francois Cliche, Michel Tetu, Christine Latrasse, Alain Zarka
  • Patent number: 5780843
    Abstract: Calibration of a variable frequency light source is performed by a control unit which has a knowledge of the known transmission pattern of an optical filter, such as gas cell or a calibrated interferometer, having a number of known frequency dependent transmission characteristics in the tuning range of the optical source. This unit scans the frequency of the optical source via a frequency control signal over a frequency range and measures the optical intensity of the optical source output light after it has passed through the optical filter The measured transmission and frequency control signal values are processed and stored in memory and constitute a measured absorption pattern. Once acquired for a frequency range, this pattern is compared to the theoretical transmission pattern of the optical filter. Correspondences are made to identify the transmission features against their known counterparts. A relationship between the frequency control signal and actual frequency of the optical source is established.
    Type: Grant
    Filed: July 16, 1996
    Date of Patent: July 14, 1998
    Assignee: Universite Laval
    Inventors: Jean-Fran.cedilla.ois Cliche, Michel Tetu, Christine Latrasse
  • Patent number: 4899345
    Abstract: A method and apparatus for deriving information on a light beam. The light beam is processed by an optical system to produce two quasi-collinear beams propagating in opposite directions, namely pump and probe beams with orthogonal linear polarizations. The beams interact with the medium contained in a cell, which medium is capable to manifest absorption resonance. As a result of the beams interaction with the medium, the intensity of the probe beam transmitted through the medium, considered along a predetermined polarization axis, becomes representative of a particular state of absorption resonance of the medium, which resonance occurs when the frequencies of the pump and probe beams are located within a narrow absorption resonance frequency bandwidth characterizing the medium. The invention finds applications in the laser spectroscopy technology as well as in the construction of frequency stabilized laser sources, optical filters and optical communication systems, among others.
    Type: Grant
    Filed: April 21, 1989
    Date of Patent: February 6, 1990
    Assignee: Universite Laval
    Inventors: Normand Cyr, Michel Tetu, Vincent Giordano