John Z Zyskind

US Patent:

6396051, May 28, 2002

Filed:

Jun 7, 2000

Appl. No.:

09/589942

Inventors:

Jinghui Li - North Billerica MA
Eric Swanson - Acton MA
John Zyskind - Concord MA

Assignee:

Sycamore Networks, Inc. - Chelmsford MA

International Classification:

G01J 400

US Classification:

25022718, 359110

Abstract:

An apparatus for measuring the optical-signal-to-noise ratio (OSNR) of an optical system is adapted to function in single channel or in multi-channel wavelength division multiplexed optical communication systems. An optical signal spectrum and a center frequency characterize the optical signals. A narrow-band notch filter, realized by an in-fiber Bragg grating, is utilized to remove a component of the signal so the remaining signal can be measured. When multiple channels are present, a bandpass filter is used to select the part of the multiplexed signal to be measured. Both the narrow-band notch filter and the bandpass filter can be tunable to further extend the capabilities of the system. Two detectors are utilized with the power in the channel being measured by a low-gain detector and the power in the noise being measured by a high-gain detector. A processor receives the detector outputs, calculates OSNR, and controls the tunable components.

US Patent:

6456427, Sep 24, 2002

Filed:

Jan 3, 2001

Appl. No.:

09/754832

Inventors:

Yijiang Chen - Chelmsford MA
John L. Zyskind - Concord MA
Graeme J. Pendock - Merrimack NH

Assignee:

Sycamore Networks, Inc. - Chelmsford MA

International Classification:

H04B 1012

US Classification:

3593371, 359110

Abstract:

Methods and systems for reducing a first tilt of a spectrum of light transmitted via an optical fiber are provided. To reduce the first tilt, an amplifier, such as an erbium doped fiber amplifier, is configured to yield a gain spectrum with an opposite tilt to that of the first tilt. When light traverses the fiber by passing the amplifier, the first tilt of the spectrum and the opposite tilt of the gain spectrum cancel partially or totally, thereby reducing the first tilt.

US Patent:

6529315, Mar 4, 2003

Filed:

Apr 27, 2001

Appl. No.:

09/844875

Inventors:

Glenn Bartolini - Waltham MA
Graeme Pendock - Merrimack NH
John Zyskind - Concord MA

Assignee:

Sycamore Networks, Inc - Chelmsford MA

International Classification:

H01S 300

US Classification:

359334, 3593375

Abstract:

A dispersion-compensating fiber amplifier having a Raman pumped dispersion-compensating fiber and a distributed optical amplifier. The dispersion-compensating fiber is pumped such that the noise contribution of the dispersion-compensating fiber is reduced.

US Patent:

6602002, Aug 5, 2003

Filed:

Feb 19, 1999

Appl. No.:

09/253279

Inventors:

Atul Kumar Srivastava - Eatontown NJ
James William Sulhoff - Ocean NJ
Yan Sun - Middletown NJ
John Lehrer Zyskind - Hummelstown PA

Assignee:

Lucent Technologies Inc. - Murray Hill NJ

International Classification:

H04B 1000

US Classification:

398113, 398160, 398 87, 398 97, 398180, 35933721, 359349

Abstract:

A high-capacity optical transmission arrangement utilizing a plurality of laser sources and a plurality of wide-band optical amplifiers permit the reliable transmission of 1 Tb/sec rates over significant distances of optical fiber.

US Patent:

7173756, Feb 6, 2007

Filed:

Feb 17, 2005

Appl. No.:

10/906382

Inventors:

John Zyskind - Concord MA, US
Andrew Niall Robinson - Lincoln MA, US
Seo Yeon Park - Westford MA, US
Clement Dowd Burton - Westwood MA, US
John Jacob - Hollis NH, US
Erik Robert Thoen - Cambridge MA, US

Assignee:

JDS Uniphase Corporation - Milpitas CA

International Classification:

H01S 3/00

US Classification:

359337, 3593374

Abstract:

An optical communications system includes a plurality of optical fiber spans. An optical loss of one of the plurality of optical fiber spans is different from an optical loss of another one of the plurality of optical fiber spans. At least one of the plurality of optical fiber spans includes an optical loss that is greater than or equal to 35 dB and at least one of the plurality of optical fiber spans includes an optical loss that is less than 30 dB. An optical amplification system includes at least one discrete optical amplifier, at least one distributed optical amplifier, and an optical loss element. The optical amplification system has spectral gain that compensates for substantially all losses experienced by the optical signals propagating in the plurality of optical fiber spans.

US Patent:

7218442, May 15, 2007

Filed:

Mar 4, 2005

Appl. No.:

10/906759

Inventors:

Enis Akbaba - Westford MA, US
John Jacob - Hollis NH, US
Andrew Niall Robinson - Lincoln MA, US
John Zyskind - Concord MA, US
Erik Robert Thoen - Cambridge MA, US

Assignee:

JDS Uniphase Corporation - Milpitas CA

International Classification:

H01S 3/00
H04B 10/08
H04B 17/00

US Classification:

359334, 398 15, 398 25

Abstract:

An optical communications system initiates automatic power reduction by selecting a portion of a Raman optical pumping signal from optical signals propagating on an optical fiber span. A signal related to a magnitude of the selected portion of the Raman optical pumping signal is generated. Power of at least one of the optical data signals and the optical pumping signals propagating in the optical fiber span is reduced in response to the generated signal.

US Patent:

20060140626, Jun 29, 2006

Filed:

Dec 24, 2004

Appl. No.:

10/905294

Inventors:

Andrew Robinson - Lincoln MA, US
John Jacob - Hollis NH, US
Erik Thoen - Cambridge MA, US
Seo Park - Westford MA, US
John Zyskind - Concord MA, US
Enis Akbaba - Westford MA, US

Assignee:

OPTOVIA CORPORATION - Acton MA

International Classification:

H04B 10/08

US Classification:

398030000

Abstract:

An optical supervisory channel includes a transmit path that propagates optical supervisory signals to a high span loss optical fiber span having an optical loss that is greater than 35 dB. A wavelength division multiplexer adds the optical supervisory signals to the high span loss optical fiber span. A second wavelength division multiplexer extracts the optical supervisory signals from the high span loss optical fiber span. A receive path propagates the optical supervisory signals away from the high span loss optical fiber span. The optical supervisory channel also includes a means for reducing a bit error rate of the optical supervisory channel.

US Patent:

20130163986, Jun 27, 2013

Filed:

Apr 15, 2011

Appl. No.:

13/641078

Inventors:

Pavel Mamyshev - Morganville NJ, US
John Leonard Zyskind - Concord MA, US
Seo Yeon Park - Westford MA, US
Fenghai Liu - Acton MA, US

International Classification:

H04B 10/2507

US Classification:

398 25, 398135

Abstract:

The present application describes methods and systems that improve the optical signal to noise ratio performance of an optical network without the need to vary the free spectral range associated with a differential interferometer. This is achieved by varying an electrical bandwidth of an electronic device associated with the receiver. For example, the electrical bandwidth may vary in inverse proportion to the combined effective optical bandwidth of the transmission line carrying the optical signal. The techniques described herein a applicable to a wide variety of modulation formats, including mPSK, DPSK, DmPSK, PDmPSK, mQAM, ODB, and other direct-detection formats. Using the techniques described herein, the optical signal to noise ratio and bit error ratio performance of the optical network is improved without the need to provide costly and complex differential interferometers whose free spectral range is variable.