James W Sulhoff

US Patent:

6381560, Apr 30, 2002

Filed:

Dec 9, 1999

Appl. No.:

09/457966

Inventors:

Virendra S Shah - Edison NJ
Atul Kumar Srivastava - Eatontown NJ
James William Sulhoff - Ocean NJ
Yan Sun - Middletown NJ
Liyan Zhang - Middletown NJ

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

G16F 1750

US Classification:

703 2, 359341, 385 37

Abstract:

A method of modeling erbium doped fiber (âEDFâ) for use in erbium doped fiber amplifiers (âEDFAâ). The EDF has a length and a fractional population density of erbium ions in an excited state. Since the EDF supports N channels, the power propagation along the EDF is characterized by N+1 differential equations as a function of the direction of propagation, z, of the channels along the length l of the EDF and the time t. By applying an average inversion model to a spatially averaged inversion level of the erbium ions in the fiber, the N+1 partial differential equations are reduced to a single ordinary differential equation. This allows an analytical solution at the boundary and initial conditions of the fiber so that an expression for the power of the signal propagating along the fiber can be obtained. With this expression, the single equation can be solved analytically for the inversion level at any point along the EDF.

US Patent:

6424457, Jul 23, 2002

Filed:

Dec 5, 2000

Appl. No.:

09/729085

Inventors:

James P. Koonmen - Santa Clara CA
James W. Sulhoff - Los Gatos CA
Chia-Chi Wang - Hillsborough NJ
Paul F. Wysocki - Flemington NJ

Assignee:

Onetta, Inc. - Sunnyvale CA

International Classification:

H04B 1013

US Classification:

3593371, 3593411, 3593374

Abstract:

Optical amplifiers and methods for manufacturing optical amplifiers are provided that allow amplifiers to be fabricated to match design expectations. Optical amplifiers may be manufactured by assembling passive optical components in the amplifier before assembling active optical components such as doped fiber coils. Passive losses may then be characterized and used to calculate the lengths of the fibers that should be used in the amplifier gain stages. Following corrections to the nominal doped-fiber lengths based on the measured passive losses, the passive and active components of the amplifier may be assembled and characterized. Final corrections may be made to the amplifier assembly based on these characterizations. For example, the lengths of one or more of the doped fibers may be adjusted. If desired, such length adjustments may be made to fiber coils in the mid-stage portion of the amplifier, so that the impact on the operating characteristics of the amplifier are minimized.

US Patent:

6473212, Oct 29, 2002

Filed:

Feb 19, 1999

Appl. No.:

09/253259

Inventors:

Andrew Roman Chraplyvy - Matawan NJ
Robert Meachem Jopson - Rumson NJ
Atul Kumar Srivastava - Eatontown NJ
James William Sulhoff - Ocean NJ
Yan Sun - Middletown NJ

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

H04J 1402

US Classification:

359124, 359161, 359179, 359189

Abstract:

Substantially error-free communications is achieved in an optical communication system that includes optical amplifiers by detecting bits transmitted in the amplified optical signal using a detection threshold that is derived as a function of a maximum power level associated with a first bit value, e. g. , bit â0â, and a minimum power level associated with a second bit value, e. g. , bit â1â. Importantly, this detection scheme can be used to accurately detect bit patterns in the amplified signal even in the presence of nonlinear distortions caused by gain variations, such as inter-modal distortion and saturation induced crosstalk. In a wavelength division multiplexed (WDM) system comprising semiconductor optical amplifiers, for example, the detection threshold can be set at a level corresponding to P /2N, where P represents the total power in the WDM signal and N represents the number of optical channels in the WDM signal. According to another aspect of the invention, the effect of gain fluctuations becomes smaller as the number of channels increase. In particular, a smoothing effect is realized for the total effective saturation power as gain variations decrease as a function of an increase in the number of channels.

US Patent:

6687049, Feb 3, 2004

Filed:

Aug 15, 2001

Appl. No.:

09/929141

Inventors:

James W. Sulhoff - Los Gatos CA
Yongan Wu - San Jose CA
Chia-Chi Wang - Hillsborough NJ

Assignee:

Onetta, Inc. - Sunnyvale CA

International Classification:

H04B 1012

US Classification:

3593414, 35934141, 35934142, 35934132

Abstract:

Optical amplifiers and optical network equipment are provided that have optical gain stages for amplifying optical signals on a fiber-optic communications link. The optical gain stages may be based on optically pumped fiber such as rare-earth-doped fiber. The fiber may be optically pumped using laser diode pumps. A control unit may be provided in the amplifiers or other equipment to control the laser diode pumps. Optical monitors may be used to measure the optical signals in the amplifiers or other equipment. The pump powers of the laser diode pumps may be adjusted in real time by the control unit based on the measured optical signals to suppress gain transients due to input power fluctuations on the link. To minimize the impact of pump-induced noise, the control unit may avoid operating the laser diodes at powers at which the laser diodes are most susceptible to mode partition noise.

US Patent:

7903980, Mar 8, 2011

Filed:

Jun 19, 2007

Appl. No.:

11/765152

Inventors:

Fernando X. Villarruel - Romeoville IL, US
Steven C. Condra - Plainfield IL, US
Yihong Chen - Naperville IL, US
Kevin L. Sweeney - Naperville IL, US
James W. Sulhoff - Naperville IL, US

International Classification:

H04B 10/04
H04B 10/12
H04J 14/02

US Classification:

398193, 398 90, 398201

Abstract:

Provided herein are embodiments of a device, method of use and system for a low-cost analog multi-wavelength video distribution transamplifier for CATV and FTTH networks having a broadband overlay. The transamplifier embodiments described herein allow the use of multiple wavelengths to segment logical service groups in a CATV distribution system and a FTTH system having a broadband overlay. Improved optical signal power performance can be achieved by using direct modulating transmitters and modulating the optical signal for with an external waveguide, thereby decreasing SBS and reducing non-linearities.

US Patent:

8111992, Feb 7, 2012

Filed:

Jun 19, 2007

Appl. No.:

11/765078

Inventors:

Fernando X. Villarruel - Romeoville IL, US
Steven C. Condra - Plainfield IL, US
Yihong Chen - Naperville IL, US
Kevin L. Sweeney - Naperville IL, US
James W. Sulhoff - Naperville IL, US

International Classification:

H04J 14/02

US Classification:

398 79, 398192

Abstract:

Provided herein are embodiments of a device, method of use and system for a low-cost analog multi-wavelength video distribution transamplifier for CATV and FTTH networks having a broadband overlay. The transamplifier embodiments described herein allow the use of multiple wavelengths to segment logical service groups in a CATV distribution system and a FTTH system having a broadband overlay.

US Patent:

8265490, Sep 11, 2012

Filed:

May 28, 2009

Appl. No.:

12/473736

Inventors:

Fernando X. Villarruel - Romeoville IL, US
Steven C. Condra - Plainfield IL, US
Yihong Chen - Naperville IL, US
Kevin L. Sweeney - Naperville IL, US
James W. Sulhoff - Naperville IL, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04B 10/04
H04B 10/12

US Classification:

398193, 398201

Abstract:

Disclosed herein are embodiments of a device, method of use and system for an analog multi-wavelength transamplifier. The transamplifier embodiments described herein allow the use of multiple wavelengths to segment logical service groups, such as for use in a CATV distribution system and a FTTH system having a broadband overlay. Improved optical signal power performance can be achieved by using direct modulating transmitters and maintaining polarization of the optical signals that are modulated by a phase modulator, such as an external waveguide.

US Patent:

60942983, Jul 25, 2000

Filed:

Jul 6, 1999

Appl. No.:

9/348112

Inventors:

Gengxian Luo - Aberdeen NJ
Atul K. Srivastava - Eatontown NJ
James W. Sulhoff - Ocean NJ
Yan Sun - Aberdeen NJ
John L. Zyskind - Shrewsbury NJ

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

H01S 330

US Classification:

359346

Abstract:

An Erbium doped fiber amplifier (EDFA) is placed in a laser cavity to clamp the gain of the amplifier. The laser cavity is preferably formed to minimize the effects of relaxation oscillations and of spectral hole burning. In a preferred embodiment, the laser cavity supports a lasing wavelength which makes the saturation energy at the laser wavelength less than that at the signal wavelengths. In an erbium doped fiber implementation, the laser wavelength is shorter than that of the signal wavelengths and is separated from them by no more than approximately 75% of the width of the spectral hole. The compounding of relaxation oscillations may be substantially eliminated by varying the length of the fiber within each laser cavity within a system to change the photon round-trip time within each cavity.