Patents by Inventor Ton V. Nguyen

Ton V. Nguyen 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).

  • Amplitude detection scheme for optical transmitter control
    Patent number: 5448629
    Abstract: An amplitude control scheme for a high bit rate digital optical transmitter is disclosed. The data to be transmitted by the laser is pulse-width modulated by a low frequency signal. The pulse-width modulated signal is applied to the laser via a laser driver and to a mark density reference generator. The magnitude of the low frequency components from the mark density reference generator is a signal indicative of the desired amplitude of the laser light pulses. A back-face photodiode converts a portion of the laser light into an electrical signal, the magnitude of the low frequency portion thereof being a signal indicative of the actual amplitude of the laser light pulses. The actual amplitude of the laser light pulses is compared to the desired amplitude and the laser driver output amplitude may then adjusted to compensate for variations in the laser performance.
    Type: Grant
    Filed: October 14, 1993
    Date of Patent: September 5, 1995
    Assignee: AT&T Corp.
    Inventors: Fridolin L. Bosch, Ton V. Nguyen
  • Method for controlling the amplitude of an optical signal
    Patent number: 5373387
    Abstract: An amplitude control scheme for a high bit rate digital optical transmitter is disclosed. The data to be transmitted by the laser is pulse-width modulated by a low frequency signal. The pulse-width modulated signal is applied to the laser via a laser driver and to a mark density reference generator. The magnitude of the low frequency components from the mark density reference generator is a signal indicative of the desired amplitude of the laser light pulses. A back-face photodiode converts a portion of the laser light into an electrical signal, the magnitude of the low frequency portion thereof being a signal indicative of the actual amplitude of the laser light pulses. The actual amplitude of the laser light pulses is computed to the desired amplitude and the laser driver output amplitude may then adjusted to compensate for variations in the laser performance.
    Type: Grant
    Filed: October 14, 1993
    Date of Patent: December 13, 1994
    Assignee: AT&T Corp.
    Inventors: Fridolin L. Bosch, Ton V. Nguyen