Ciena Corporation

Cecil D Smith

Stephen B Alexander

Steve W Chaddick

Roy C Litz

David R Huber

Michael Y Frankel

Robert Corwin

Donald T Newman

John L Shanton, Iii

Steve S Cho

Mark Lucas

William J Ulrich, Iii

Bradley Kanack

The present disclosure provides high-speed wavelength division multiplexing (WDM) transponders (e.g., 10 Gb/s, 40 Gb/s, 100 Gb/s, and beyond) that receive one or more optical signals and convert and/or remodulate the received optical signals onto a newly generated optical channel along with overhead processing/addition, forward error correction, and the like. In general, the transponders of the present invention include a client-side and a line-side, each with bi-directional optical transmission. The transponders provide an effective mechanism to support WDM networks that are transparent to the client-side.

High-speed optical transponder systems

The present invention provides a remodulating channel selector for a wavelength division multiplexed optical communication system. The remodulating selector receives a WDM input signal, selects a particular optical channel from the WDM signal and places the information from the selected signal onto a newly-generated optical output signal. The wavelength of the output optical signal can be the same as or different from one of the optical channels which comprises the WDM input signal. When used in a WDM optical communication system with remodulators at the transmission input, the remodulating selectors provide complete control over the interfaces with optical transmitters and receivers, permitting use with a broad range of optical equipment.

Remodulating channel selectors for WDM optical communication systems

The present invention provides a software-based electro-optic modulator bias control system resident in an optical transceiver including an electro-optic modulator that includes an optical-to-electrical converter including a transimpedance amplifier, an analog-to-digital converter, and a software algorithm, wherein the software algorithm is operable for determining an optimum bias voltage applied to the electro-optic modulator by discovering a maximum average optical power transmitted by the electro-optic modulator, or quadrature point, wherein the quadrature point is discovered by determining at what bias voltage the slope of an average optical power transmitted by the electro-optic modulator, defined as an optical power change given an incremental bias voltage change, is equal to zero. The software-based electro-optic modulator bias control system also includes a control loop operable for determining if a radio frequency port of the electro-optic modulator is driven to a peak-to-peak voltage that is greater than (over-driven) or less than (under-driven) the peak-to-trough voltage of a response curve of the electro-optic modulator.

Software-based electro-optic modulator bias control systems and methods

In accordance with an aspect of the present invention, a circuit is provided which is configured to recover clock and data streams from an incoming signal. The circuit comprises a multiplexer having first and second inputs, and an output. The first input is configured to receive the incoming signal, and the second input is configured to receive a reference clock signal, while the output selectively supplies one of the incoming and reference clock signals. A toggling circuit, such as a flip-flop, and a frequency multiplier circuit are further provided which are coupled to the multiplexer output. A filter circuit is coupled to the frequency multiplier circuit, and the output of the filter circuit is coupled to a second input of the toggling circuit. Moreover, the output of the filtering circuit corresponds to the recovered clock stream, and an output of the toggling circuit corresponds to the recovered data stream.

Surface acoustic wave-based clock and data recovery circuit

The present invention provides a system and method for intelligently shutting down an optical energy source in a communication system having optical amplifiers upon detection of a system failure.

System and method for shutting off an optical energy source in a communication system having optical amplifiers

The present invention provides a WDM optical communication system with remodulators at the transmission input and remodulating channel selectors adjacent the optical receivers, providing complete control over the interfaces with optical transmission equipment. In an exemplary embodiment, the WDM system includes optical transmitters which input transmitted optical signals into optical remodulators. The optical remodulators place the information from each of the transmitted signals onto separate optical channels in the WDM system channel plan. The optical channels are multiplexed onto an optical waveguide. At the receive end, remodulating channel selectors each receive a portion of the WDM optical signal, select a particular optical channel, and place the information from the selected channel onto a newly-generated optical signal. This newly-generated optical signal is output to a receiver or to a further WDM optical system.

WDM Optical communication systems with remodulators and remodulating

A WDM optical communication system is described which is capable of placing information from incoming information-bearing optical signals onto N optical signal channels for conveyance over an optical waveguide. The optical system includes a first set of one or more optical transmitters, each of which emits an information-bearing optical signal at one or more transmission wavelengths, .lambda..sub.Ti. At least M optical receiving systems are provided, each receiving system configured to receive an information-bearing optical signal at a particular reception wavelength .lambda..sub.j, where M is a whole number greater than or equal to N and j is from 1 to M. Each receiving system includes at least one Bragg grating member for selecting the particular reception wavelength .lambda..sub.j. An optical waveguide optically communicates with each of the M receiving systems for transmitting a plurality of optical signals. A plurality of optical remodulators is further included for communicating with the first set of optical transmitters and the optical waveguide. Each optical remodulator is configured to receive an information-bearing optical signal at a transmission wavelength .lambda..sub.Ti and output an information-bearing optical signal at a reception wavelength .lambda..sub.j. A second set of one or more optical transmitters is also provided, each of which emitting a

WDM optical communication system with remodulators and diverse optical

The present invention provides an optical communication system capable of placing incoming information-bearing optical signals onto plural optical signal channels for transmission over an optical waveguide. The optical system includes plural optical transmission elements, each transmission element emitting an information-bearing optical signal at a first transmission wavelength. Plural optical receiving systems are provided, each receiving system configured to receive an information-bearing optical signal at a particular reception wavelength. Each receiving system includes an optical filtering member comprising at least one Bragg grating member for selecting the particular reception wavelength. An optical waveguide optically communicates with each of the receiving systems for transmitting a plurality of optical signals. A plurality of optical amplifiers are positioned along the optical waveguide for amplifying plural optical signals simultaneously. A plurality of optical remodulators optically communicates with the optical transmission elements and the optical waveguide. Each optical remodulator is configured to receive an information-bearing optical signal at a transmission wavelength and output an information-bearing optical signal at a reception wavelength corresponding to a channel wavelength of the optical communication system. Each optical remodulator includes an optoelectronic element for receiving an information-bearing optical signal at a transmission wavelength and outputting a corresponding electrical signal which includes the information from the transmission information-bearing optical signal. The remodulator further includes an optical carrier emitting element comprising a light source for transmitting a non-information-bearing carrier optical signal at a reception wavelength. The remodulator additionally comprises an external modulator for imparting information directly onto the carrier optical signal from the electrical Signal. In this manner, incoming transmission signals are placed on the particular optical signal channels employed in the WDM system.

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Severna Park, MD, United States of America

Cecil D Smith