Patents by Inventor Frank Y. Li

Frank Y. Li 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).

  • High sensitivity acousto-optic tunable filter spectrometer
    Patent number: 5120961
    Abstract: An acousto-optical filter (AOTF) is used in a spectrometer for analysis of samples. The spectrometer provides continuous wave RF excitation through the crystal, and the spectrometer provides control and modulation for said RF source. The signal to noise ratio is improved by use of a lock-in amplifier which demodulates the modulation frequency. Fiber optics are used to connect the crystal to the source, and the source to the detection system. A digital lock-in amplifier is designed which increases the efficiency, accuracy, sensitivity and decreases the cost of conventional analog lock-in amplifier.
    Type: Grant
    Filed: March 16, 1990
    Date of Patent: June 9, 1992
    Assignee: Infrared Fiber Systems, Inc.
    Inventors: Kenneth H. Levin, Frank Y. Li