Patents by Inventor Didier Herve

Didier Herve 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).

  • Device for controlling an optical signal modulation frequency, and in particular for controlling microwave or millimetric modulation frequency
    Patent number: 6720549
    Abstract: A device for monitoring a modulation frequency of an optical signal,—in particular a device for monitoring the modulation frequency of an optical signal modulated at a microwave or millimetric frequency—, the device being characterized in that it comprises a photorefractive crystal (7), a photodetector (6), and means (8a, 8b, 8c; 9a, 9b, 9c) for applying to said crystal (7) firstly at least a fraction of the modulated optical signal and secondly a write optical signal for photoinducing a Bragg grating on said crystal (7), the orientations of the modulated optical signal and of the write optical signal relative to said crystal (7) being such that at a given wavelength of the optical signal the photodetector (6) detects an intensity for the signal reflected by the crystal (7) that reaches a maximum when the optical signal is modulated at the modulation frequency to be detected.
    Type: Grant
    Filed: July 19, 2002
    Date of Patent: April 13, 2004
    Assignee: France Telecom
    Inventors: Didier Herve, René Coquille, Jean-François Cadiou