Christopher Z Richardson

US Patent:

6701049, Mar 2, 2004

Filed:

Mar 21, 2003

Appl. No.:

10/249201

Inventors:

Ehab Awad - Hyattsville MD
Julius Goldhar - Silver Spring MD
Pak Shing Cho - Gaithersburg MD
Christopher Richardson - Columbia MD
Norman Moulton - Ellicott City MD

Assignee:

The United States of America as represented by The National Security Agency - Washington DC

International Classification:

G02F 135

US Classification:

385122, 398141, 398155

Abstract:

All-optical timing extraction and optical clock recovery for high-speed return-to-zero binary optical data streams using the timing difference between clock and data counter-propagating optical pulses in a non-linear optical waveguide where the first pulse to arrive at the non-linear optical waveguide partially saturates the transmission properties of the waveguide resulting in a change of the transmission properties seen by the lagging pulse. A balanced photo-detector makes delay-dependent comparisons of the clock and data pulses peak power and generates an error signal used in a phase-locked loop configuration to synchronize the clock to the data stream.