Xiang Liu

US Patent:

6674568, Jan 6, 2004

Filed:

Mar 11, 2002

Appl. No.:

10/095021

Inventors:

Xiang Liu - Eatontown NJ

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

H01S 300

US Classification:

359334, 3593371

Abstract:

A method and apparatus for receiving a gain profile from optical channel monitors (OMONs) and using that gain profile along with additional system parameters received from the OMONs for calculating the needed Raman pump parameters (power and/or wavelength) and adjusting the Raman pumps to those calculated parameters for achieving any pre-determined broadband signal gain or power profile. The calculated Raman pump parameters are scaled to be within a range of predetermined acceptable values.

US Patent:

7010180, Mar 7, 2006

Filed:

Aug 13, 2003

Appl. No.:

10/639824

Inventors:

Adriaan J. de Lind van Wijngaarden - New Providence NJ, US
Xiang Liu - Marlboro NJ, US
Chongjin Xie - Morganville NJ, US

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

G02B 6/00

US Classification:

385 11, 385 3, 385 24, 359483, 398152

Abstract:

A system and method for multi-channel PMD/PDL/PDG mitigation, the system including polarization scramblers adapted to vary the state of polarization of an optical signal propagated through the system to effectively vary the polarization mode dispersion experienced by the signal during each burst-error-correcting-period of the forward error correction used in the system.

US Patent:

7027669, Apr 11, 2006

Filed:

Aug 15, 2003

Appl. No.:

10/641414

Inventors:

Juerg Leuthold - Eatontown NJ, US
Xiang Liu - Marlboro NJ, US
Xing Wei - New Providence NJ, US

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

G02F 1/035

US Classification:

385 3, 385 1, 385 4, 359279, 398189

Abstract:

Systems and techniques for generating optical pulses exhibiting a progressive phase shift, and the use of those pulses to transmit data, are described. One embodiment of the invention employs a Mach-Zehnder modulator using electrical signals chosen to introduce a predetermined frequency shift at the center of each pulse generated by the pulse generator. This frequency shift is achieved by introducing a timing difference between the electrical input signals. Another embodiment of the invention employs a chirp free pulse generator and a separate phase modulator to induce the desired frequency or phase shift. These progressively phase shifted pulses may be further modulated to transmit data by introducing phase or amplitude modulation on the optical pulses, depending on the data to be transmitted.

US Patent:

7062176, Jun 13, 2006

Filed:

Dec 30, 2002

Appl. No.:

10/331217

Inventors:

Xiang Liu - Marlboro NJ, US
Colin J McKinstrie - Manalapan NJ, US
Linn Frederick Mollenauer - Colts Neck NJ, US
Richart Elliott Slusher - Lebanon NJ, US
Xing Wei - New Providence NJ, US
Chunhui Xu - Ithaca NY, US

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

H04B 10/02
H04B 10/18
G02B 5/00
G02F 1/03
G02F 1/355
H04B 10/06
G02F 1/35
G02F 1/377

US Classification:

398159, 398208, 385 1, 385122

Abstract:

A nonlinear phase-shift compensation method and apparatus is provided for improving system performance in optical transmission systems. The apparatus includes a phase-shift compensating device that provides a partial compensating phase shift to reduce the nonlinear phase noise resulting from self-phase modulation and amplified spontaneous emissions in an optical transmission system.

US Patent:

7133191, Nov 7, 2006

Filed:

Dec 29, 2004

Appl. No.:

11/025436

Inventors:

Douglas M. Gill - South Orange NJ, US
Xiang Liu - Marlboro NJ, US

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

G02F 1/365
G02B 6/26

US Classification:

359326, 385 15, 385 27, 385122, 398158

Abstract:

A device and method for processing a signal e. g. equalizing a signal, is disclosed. Such processing involves dividing a signal into two portions that each traverses a wavepath and then are combined. The respective wavepaths impose a non-linear frequency-versus-phase dependency on a signal portion. The frequency-versus-phase dependencies that characterize the respective wavepaths are similar in shape but inverted from each other. A processed signal has significantly improved signal-to-noise ratio.

US Patent:

7277645, Oct 2, 2007

Filed:

Mar 14, 2002

Appl. No.:

10/099077

Inventors:

Douglas M Gill - South Orange NJ, US
Xiang Liu - Marlboro NJ, US
Xing Wei - New Providence NJ, US

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

H04B 10/04

US Classification:

398185, 398187

Abstract:

A 90 degree Alternate-Phase (AP) on-off keying (OOK) transmission format for high bit rate, long-haul optical transmission systems employing a chirped or a chirp-free pulse stream generated by a pulse generator (e. g. , Mach Zehnder modulator) driven by mixing two electrical signals—one for intensity modulation and another for pulse modulation. These electrical signals may be two properly skewed sinusoidal electrical signals at half the desired data rate thereby generating a pulse stream in which the maximum optical phase modulation occurs at the intensity peak of each pulse and is 90 degrees out of phase with its nearest neighbors.

US Patent:

7277647, Oct 2, 2007

Filed:

Mar 14, 2002

Appl. No.:

10/099105

Inventors:

Douglas M Gill - South Orange NJ, US
Xiang Liu - Marlboro NJ, US
Xing Wei - New Providence NJ, US

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

H04B 10/04

US Classification:

398188, 398182, 398189

Abstract:

Minimum shift keying (MSK) is used as the coding scheme in a high bit rate optical transmission system, and the signal format is either RZ (return-to-zero) or NRZ (non-return-to-zero). The system can combine multiple individual channels with different wavelengths in a WDM or dense wavelength division multiplexed (DWDM) arrangement. Dispersion management can be provided using several techniques, such as quasi-linear transmissions or conventional RZ transmissions. At the transmitter, an optical MSK transmitter is used to modulate the phase of a stream of high bit rate (e. g. , 40 Gbit/s) optical signals. Many such data streams can be combined in a wavelength division multiplexer and transmitted to a remote receiver, where the signal is wavelength division demultiplexed. The encoded data in each wavelength channel is then recovered by an MSK receiver, which may consist of a delay demodulator and a balanced detector.

US Patent:

7283752, Oct 16, 2007

Filed:

Mar 31, 2004

Appl. No.:

10/813960

Inventors:

Xiang Liu - Marlboro NJ, US

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

H04B 10/00

US Classification:

398152, 398147, 398158

Abstract:

An optical communication method and apparatus are provided, the apparatus including polarization controllers, and drive circuitry for driving the polarization controllers at a plurality of frequencies such that the penalties from PMD, PDL and PDG are mitigated.