Massachusetts Institute of Technology

Neal W Spellmeyer

David O Caplan

Don M Boroson

Bryan Shawn Robinson

Scott A Hamilton

Marc Norvig

Hemonth G Rao

A burst-mode phase shift keying (PSK) communications apparatus according to an embodiment of the present invention enables practical, power-efficient, multi-rate communications between an optical transmitter and receiver. Embodiments may operate on differential PSK (DPSK) signals. An embodiment of the apparatus includes an average power limited optical transmitter that transmits at a selectable data rate with data transmitted in bursts, the data rate being a function of a burst-on duty cycle. DPSK symbols are transmitted in bursts, and the data rate may be varied by changing the ratio of the burst-on time to the burst-off time. This approach offers a number of advantages over conventional DPSK implementations, including near-optimum photon efficiency over a wide range of data rates, simplified multi-rate transceiver implementation, and relaxed transmit laser line-width requirements at low data rates.

Method and apparatus for transmitting phase shift keyed optical signals

A burst-mode phase shift keying (PSK) communications system according to an embodiment of the present invention enables practical, power-efficient, multi-rate communications between an optical transmitter and receiver. Embodiments may operate on differential PSK (DPSK) signals. An embodiment of the system utilizes a single interferometer in the receiver with a relative path delay that is matched to the DPSK symbol rate of the link. DPSK symbols are transmitted in bursts, and the data rate may be varied by changing the ratio of the burst-on time to the burst-off time. This approach offers a number of advantages over conventional DPSK implementations, including near-optimum photon efficiency over a wide range of data rates, simplified multi-rate transceiver implementation, and relaxed transmit laser line-width requirements at low data rates.

Method and apparatus for phase shift keyed optical communications

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Arlington, MA, United States of America

Neal W Spellmeyer