Jeffrey P Nicholson

US Patent:

6504973, Jan 7, 2003

Filed:

Mar 16, 2002

Appl. No.:

10/099820

Inventors:

David J. DiGiovanni - Montclair NJ
William Alfred Reed - Summit NJ
Jeffrey W. Nicholson - Chatham NJ
Man Fei Yan - Berkeley Heights NJ
Bera Palsdottir - Copenhagen, DK

Assignee:

Fitel USA Corp. - Norcross GA

International Classification:

G02B 626

US Classification:

385 27, 385123, 359160, 359334, 372 6

Abstract:

A Raman amplified dispersion compensation module has a first dispersion compensating fiber (DCF) with an input end and an output end. The first DCF has a known Raman gain coefficient (g ()), Raman effective fiber area (A ), and dispersion characteristic. An input end of a second DCF is arranged to receive light signals from the output end of the first DCF. The second DCF has a known gain coefficient and effective area, and a dispersion characteristic selected to cooperate with that of the first DCF to produce a desired total module dispersion. The lengths of the DCFs are selected in a manner that optimizes the overall module gain.

US Patent:

7228029, Jun 5, 2007

Filed:

Sep 20, 2005

Appl. No.:

11/230905

Inventors:

Siddharth Ramachandran - Hoboken NJ, US
Jeffrey Nicholson - Chatham NJ, US

Assignee:

Furukawa Electric North America Inc. - Norcross GA

International Classification:

G02B 6/26
G02B 6/02
H01S 3/30

US Classification:

385 28, 385 27, 385123, 385127, 372 6

Abstract:

The specification describes an optical fiber device for propagating and recompressing high energy, ultrashort pulses with minimal distortions due to nonlinearity. The device is based on propagation in a higher order mode (HOM) of a few-moded fiber. Coupling into the HOM may be accomplished using long-period gratings. Features of the HOM fiber mode that are useful for high quality pulse compression include large effective area, high dispersion and low dispersion slope. In a preferred case the long period gratings go through a turn-around point (TAP) at the wavelength of operation.