Massachusetts Institute of Technology

Alcatel Communications, Inc.

United States of America As Represented by the Secretary of the Air Force

Daniel T Moriarty

Farhad Hakimi

Hosain Hakimi

Kristin A Rauschenbach

Jerry D Hutchinson

The present invention includes a design for a 20-gigabit per second two to one multiplexor, that uses: first and second input amplifiers that respectively provide output signals by respectively receiving and amplifying first and second ten-gigabit per second input signals; first and second power dividers that each produce two output data streams by respectively splitting the output signals of the first and second input amplifiers; first and second mixers that produce output signals by respectively mixing output signals of the first and second power dividers with a 10 GHz local oscillator signal; a second means for combining signals that produces an output signal by combining the output signal of the second mixer with an output data stream of the second power divider; a T/2 delay line that produces an output signal by delaying the output signal of the second combining means; and an output combiner means that outputs a 20-gigabit per second data stream by combining the output signal of the T/2 delay line with the output signal of the first combining means.

Twenty gigabit per second two to one multiplexor

A control circuit for a laser diode includes a power controller and a wavelength controller. The power controller adjusts a bias current to the laser diode to change the power output of the laser diode. The power change can have a corresponding wavelength shift effect on the nominal operating wavelength of the laser diode. The wavelength controller compensates for the wavelength shift such that the laser diode maintains operation at the nominal wavelength. The circuit provides for electrical control of the laser output power without the need for a costly and bulky optical attenuator. The circuit also provides wavelength control to compensate for the relationship between laser diode operating temperature and wavelength.

Power control circuit for laser diode having wavelength compensation

A control circuit includes a power controller for adjusting a bias current to a laser diode to change the power output of the laser diode, the change in power having a corresponding wavelength shift effect on the nominal operating wavelength of the laser diode and a monitoring circuit for sensing the bias current to the laser diode and for generating an output signal in response to the sensed bias current. The control circuit further includes a wavelength controller which receives the output signal from the monitoring circuit and in response to the output signal compensates for the wavelength shift such that the laser diode maintains operation at the nominal wavelength.

A method introduces variable time offsets into a stream of optical pulses. The method includes receiving a plurality of coherent optical pulses, receiving a plurality of control signals, and forming a coherent pulse array (CPA) from each pulse in response to one of the received control signals. Temporal spacings between pulses of each CPA are responsive to the associated one of the received control signals. For optical control signals, response times can be very short. The method further includes transmitting each pulse through a dispersive optical medium. The act of transmitting makes pulses of each CPA overlap to form an interference pattern.

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Hudson, MA, United States of America

Daniel T Moriarty