Resumes
Resumes
Chunhui Xu Phones & Addresses
-
5 Estates Dr, Ithaca, NY 14850 (607) 257-9340
-
510 Sheffield Ct, Piscataway, NJ 08854 (732) 743-0855
-
12 Summit Ave, Summit, NJ 07901 (908) 608-0927
Work
Position:
Construction and Extraction Occupations
Education
Degree:
High school graduate or higher
Publications
Us Patents
Ultra-Fast Probe
View pageUS Patent:
6400165, Jun 4, 2002
Filed:
Feb 2, 2000
Appl. No.:
09/496985
Inventors:
Wayne Harvey Knox - Holmdel NJ
Chunhui Xu - Piscataway NJ
Chunhui Xu - Piscataway NJ
Assignee:
Lucent Technologies Inc. - Murray Hill NJ
International Classification:
G01R 31302
US Classification:
324752, 324766, 250214
Abstract:
An electrooptic probe for measuring the voltage at regions of an ultra fast device under test includes a standard gallium arsenide substrate that includes on a front surface a film of LT GaAs whose surface includes a conductive stripe that includes first and second portions separated by a gap, the first portion for contacting the region under test, and the second portion for connection to a measuring instrument. The probe is irradiated with a pulsed beam of light, advantageously from a mode-locked femtosecond laser focused at the gap in the stripe and of appropriate two photons, for making conducting by two-photon absorption the region of the film underlying the gap. Preferably the beam irradiates the back surface of the probe to pass through its substrate to reach the gap. Alternatively the beam can irradiate the back surface of the device under test to reach the gap.
Process For Fabricating Tapered Microstructured Fiber System And Resultant System
View pageUS Patent:
6658183, Dec 2, 2003
Filed:
Oct 20, 2000
Appl. No.:
09/692955
Inventors:
Juhi Chandalia - Newtown Square PA
David John DiGiovanni - Montclair NJ
Benjamin John Eggleton - Summit NJ
Sandra Greenberg Kosinski - Murray Hill NJ
Xiang Liu - Eatontown NJ
Robert Scott Windeler - Annandale NJ
Chunhui Xu - Piscataway NJ
David John DiGiovanni - Montclair NJ
Benjamin John Eggleton - Summit NJ
Sandra Greenberg Kosinski - Murray Hill NJ
Xiang Liu - Eatontown NJ
Robert Scott Windeler - Annandale NJ
Chunhui Xu - Piscataway NJ
Assignee:
Lucent Technologies Inc. - Murray Hill NJ
International Classification:
G02B 626
US Classification:
385 48, 385 43, 264 124
Abstract:
The invention involves providing a microstructured fiber having a core region, a cladding region, and one or more axially oriented elements (e. g. , capillary air holes) in the cladding region. A portion of the microstructured fiber is then treated, e. g. , by heating and stretching the fiber, such that at least one feature of the fiber microstructure is modified along the propagation direction, e. g. , the outer diameter of the fiber gets smaller, the axially oriented elements get smaller, or the axially oriented elements collapse. The treatment is selected to provide a resultant fiber length that exhibits particular properties, e. g. , mode contraction leading to soliton generation, or mode expansion. Advantageously, the overall fiber length is designed to readily couple to a standard transmission fiber, i. e. , the core sizes at the ends of the length are similar to a standard fiber, which allows efficient coupling of light into the microstructured fiber length.
Optical Device For Generating Pulsed Light
View pageUS Patent:
6795617, Sep 21, 2004
Filed:
Apr 30, 2003
Appl. No.:
10/426900
Inventors:
Mihaela Dinu - Freehold NJ
Charles Kerbage - Berkeley Heights NJ
Xiang Liu - Marlboro NJ
Francesco Quochi - Quartu SantElena, IT
Robert S. Windeler - Annandale NJ
Chunhui Xu - Ithaca NY
Charles Kerbage - Berkeley Heights NJ
Xiang Liu - Marlboro NJ
Francesco Quochi - Quartu SantElena, IT
Robert S. Windeler - Annandale NJ
Chunhui Xu - Ithaca NY
Assignee:
Lucent Technologies Inc. - Murray Hill NJ
International Classification:
G02B 626
US Classification:
385 42
Abstract:
An optical device including a microstructured fiber pumped by an external pulsed-light source. In one embodiment, the microstructured fiber includes two waist regions functioning as a tunable attenuator and a wavelength shifter, respectively. Output wavelength of the optical device is selected by attenuating the pump light in the first waist region and then passing the light through the second waist region to shift the pump energy to a new spectral band. An optical device of the invention configured with two or more microstructured fibers generates two or more synchronized pulsed beams, each at a different characteristic wavelength. Certain embodiments of the invention provide an inexpensive, compact, energy-efficient multi-wavelength synchronized pulsed-light source.
Method, Apparatus And System For Reducing Gain Ripple In A Raman-Amplified Wdm System
View pageUS Patent:
6859306, Feb 22, 2005
Filed:
Feb 4, 2003
Appl. No.:
10/357646
Inventors:
Daniel A. Fishman - Lakewood NJ, US
Stefan Hunsche - Sunnyvale CA, US
Xiang Liu - Marlboro NJ, US
Mahan Movassaghi - Middletown NJ, US
Chunhui Xu - Ithaca NY, US
Stefan Hunsche - Sunnyvale CA, US
Xiang Liu - Marlboro NJ, US
Mahan Movassaghi - Middletown NJ, US
Chunhui Xu - Ithaca NY, US
Assignee:
Lucent Technologies Inc. - Murray Hill NJ
International Classification:
H01S003/00
US Classification:
359334, 35934141, 3593374
Abstract:
A method, apparatus and system for reducing gain ripple in a Raman-amplified WDM system includes determining a gain profile of an optical signal transported via a first Raman amplification span in a Raman-amplified WDM system, comparing the determined gain profile to a gain profile of an optical signal transported via a second Raman amplification span, determining, from the comparison, an amount of wavelength adjustment required for a plurality of Raman pumps comprising at least one Raman pump block of the second Raman amplification span to alter the gain profile of an optical signal transported via the second Raman amplification span, such that a cumulative gain profile of an optical signal transported via the first and the second Raman amplification spans approaches a desired gain profile, and generating a control signal suitable for adjusting the wavelengths of the plurality of Raman pumps of the at least one Raman pump block an amount consistent with the determined amount.
Dynamic Measurement Of And Compensation For Impairments To Optical Data Communication Pulses Using Photon-Counting Silicon Avalanche Photodiode
View pageUS Patent:
7024111, Apr 4, 2006
Filed:
Mar 16, 2002
Appl. No.:
10/099180
Inventors:
Wayne Harvey Knox - Pittsford NY, US
Jeffrey M. Roth - Hudson MA, US
Chunhui Xu - Piscataway NJ, US
Jeffrey M. Roth - Hudson MA, US
Chunhui Xu - Piscataway NJ, US
Assignee:
Lucent Technologies Inc. - Murray Hill NJ
International Classification:
H04B 10/08
US Classification:
398 25, 398 26, 398 27, 398 28, 398 29, 398202, 398212, 398208
Abstract:
Apparatus and method is described for using a silicon photon-counting avalanche photodiode (APD) to detect at least two-photon absorption (TPA) of an optical signal, the optical signal having a wavelength range extending from 1. 2 μm to an upper wavelength region that increases as the number of photons simultaneously absorbed by the APD increases beyond two. In one embodiment, the TPA count is used by a signal compensation apparatus to reduce dispersion of a received optical pulse communication signal subjected to group velocity dispersion, polarization mode dispersion, or other signal impairment phenomena which effect the TPA count. Another embodiment, the TPA count is used to determine the optical signal-to-noise ratio of a received optical pulse communication signal. Another embodiment uses the TPA count to determine the autocorrelation between a first and second optical pulse signals as a function of the relative delay between the first and second optical pulse signals. Another embodiment uses the TPA count to achieve synchronization of a second optical pulse signal to a first optical pulse signal.
Nonlinear Phase-Shift Compensation Method And Apparatus
View pageUS 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
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
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.
Dynamic Measurement Of And Compensation For Impairments To Optical Data Communication Pulses
View pageUS Patent:
7206522, Apr 17, 2007
Filed:
Apr 24, 2002
Appl. No.:
10/128939
Inventors:
Hernando Garcia - Freehold NJ, US
Daniel Charles Kilper - Fair Haven NJ, US
Jeffrey Matthew Roth - Lexington MA, US
Chunhui Xu - Piscataway NJ, US
Daniel Charles Kilper - Fair Haven NJ, US
Jeffrey Matthew Roth - Lexington MA, US
Chunhui Xu - Piscataway NJ, US
Assignee:
Lucent Technologies Inc. - Murray Hill NJ
International Classification:
H04B 10/06
US Classification:
398206, 398207, 398213
Abstract:
A photomultiplier module (PMT), preferably a PMT with a gallium arsenide (GaAs) photocathode, is used as a N-photon detector (N is an integer ≧2). The PMT detects the N-photon absorption rate of an optical signal having a wavelength range extending from 1. 0 μm to an upper wavelength region that increases as the number of photons simultaneously absorbed by the PMT increases beyond two. The N-photon absorption rate is used by a signal compensation apparatus to reduce impairments which affect the rate, such as group velocity dispersion and/or polarization mode dispersion, in a received optical pulse communication signal. The N-photon absorption rate can also be used to determine the optical signal-to-noise ratio of a received optical pulse communication signal, and/or to synchronize a second optical pulse signal with the first optical signal.
Modulation Phase Shift To Compensate For Optical Passband Shift
View pageUS Patent:
7403718, Jul 22, 2008
Filed:
Apr 24, 2002
Appl. No.:
10/128823
Inventors:
Manyalibo Joseph Matthews - Jersey City NJ, US
Chunhui Xu - Piscataway NJ, US
Chunhui Xu - Piscataway NJ, US
Assignee:
Lucent Technologies Inc. - Murray Hill NJ
International Classification:
H04B 10/04
US Classification:
398196, 398188, 398195
Abstract:
Disclosed is a technique for compensating for optical passband shift of an optical component (for example an optical demultiplexer). A broadband source coupled to a dispersive element generates a chirped pulsed optical signal. Data is modulated onto particular wavelengths of the chirped pulsed optical signal by appropriately synchronizing a data modulator. The modulated signal is transmitted to the downstream optical demultiplexer, which may be subject to passband shift due to, for example, changes in environmental conditions. A feedback signal from an output port of the demultiplexer is provided to the transmitter and is used to phase shift the modulator. The phase shift results in effectively adjusting the wavelength onto which the data is modulated to substantially correspond to the passband centers of the demultiplexer.