Method and system for ultra-high bit rate fiber-optic communications
AssigneeAlcatel-Lucent USA Inc.
InventorsXiang Liu, Lothar Benedict Erhard Josef Moeller, Yikai Su, Chongjin Xie
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Abstract
A method and system for ultra-high bit rate fiber-optic communications (e.g., 160 Gb/s) utilize a phase-correlated modulation format where phases of bits in adjacent four-bit groups in transmitted optical pulse trains are altered by π (or 180°).
Claims18
A method of synchronizing a receiver in an ultra-high bit rate fiber-optic communications network, comprising:
- modulating a coherent continuous-wave (CW) laser to form a phase-correlated optical data stream comprising a sequence of four-bit groups, wherein adjacent four-bit groups have respective phase relationships offset by π;
- and
- transmitting the phase-correlated optical data stream, wherein the phase-correlated optical data stream is adapted to be filtered at the receiver using an optical band-pass filter to recover thereby a clock signal wherein the optical band-pass filter has a bandwidth of about ¼ of a bandwidth of the modulated optical signal of the CW laser.
An apparatus for synchronizing a receiver in an ultra-high bit rate fiber-optic communications network, comprising:
- means for modulating a coherent continuous-wave (CW) laser to form a phase-correlated optical data stream comprising a sequence of four-bit groups, wherein adjacent four-bit groups have respective phase relationships offset by π;
- and
- means for transmitting the phase-correlated optical data stream, wherein the phase-correlated optical data stream is adapted to be filtered at the receiver using an optical band-pass filter to recover thereby a clock signal wherein the coherent CW laser is modulated using a fiber-based Kerr-effect shutter controlled by a modulated output signal of the pump laser.
A wavelength division multiplexing (WDM) system for ultra-high bit rate fiber-optic communications, comprising:
- a wavelength-matched transmitter at a first terminal comprises:
- a pump laser;
- an electro-optical converter for converting of data to be transmitted from the first terminal to a second terminal, the electro-optical converter including a modulator of a pump laser beam;
- a coherent continuous-wave (CW) laser;
- and
- a Kerr-effect shutter for producing, from the coherent beam of the CW laser, a phase-correlated optical data stream comprising a sequence of four-bit groups, whereby adjacent four-bit groups have respective phase relationships offset by π, wherein the shutter is controlled by a modulated signal of the pump laser;
- a fiber-optic span propagating the phase-correlated data stream between the wavelength-matched transmitter of the first terminal with a wavelength-matched receiver of a second terminal;
- and
- the wavelength-matched receiver for receiving the phase-correlated data stream comprises:
- an opto-electronic demodulator for demodulating the phase correlated data stream;
- and
- a synchronization circuit for recovering a clock signal.
Dependencies are inferred from the claim text.