General Instrument Corporation

Ciena Corporation

Other

Corning Incorporated

Corvis Corporation

General Instrument Corporation Jerrold Communications

David R Huber

Stephen B Alexander

Steve W Chaddick

Douglas W Hall

Edward F Murphy

Joseph B Glaab

Cecil D Smith

Alistair J Price

Jane M Simmons

Optical systems and devices for processing spectral groups, and optical methods for forming spectral groups, the optical system including at least one sub-network including at least one spectral group router configurable to route a plurality of optical signal channels within a spectral group, when contained within said sub-network and terminate optical channels within a spectral group, when bounding said sub-network, each optical signal channel being transmitted from one node within said sub-network to another node in said sub-network.

Optical transmission systems, devices, and methods

An optical transmission system of the present invention includes at least one transmitter configured to receive information from a plurality of optical receivers and transmit the information in a plurality of information carrying optical signal wavelengths. At least one optical receiver is configured to receive a plurality of information carrying optical signal wavelengths and a local oscillator signal. The optical receiver converts a plurality of optical signal wavelengths into a corresponding number of electrical signal frequencies. The optical systems reduce the number of transmitters and receivers required interconnecting various optical systems, as well as providing multiple wavelength regenerators and converters and add/drop devices with increased capacity and system flexibility.

Optical transmission systems, apparatuses, and methods

Apparatuses and methods are disclosed for use in optical communication systems. An optical system of the present invention includes an optical transmitter, an optical receiver, and an optical processing node optically connecting the transmitter and the receiver. The optical processing node includes at least one waveband selector configured to selectively pass at least one optical waveband of information including a plurality of information carrying wavelengths from the transmitter to the receiver. In an embodiment, the optical processing node includes a switch configured to separate an optical signal into optical wavebands of information and selectively pass the optical wavebands to the receiver without separating the plurality of information carrying wavelengths into individual wavelengths. In an embodiment of the optical transmission system, a plurality of nodes containing optical transmitters, receivers, and/or switching equipment are interconnected using optical processing nodes to form the network. The assignment of wavelengths to information and to destination can be performed at the client system interface with the optical network to provide for wavelength and waveband management without wavelength conversion.

Optical communication system

Optical systems including an optical amplifier and a narrow bandwidth optical filter for removing undesired spontaneous emission. An in-fiber Bragg grating reflector reflects substantially only the input amplified signal back to a circulator port of an optical circulator where the desired amplified signal is coupled from the next circulator port. The undesired emission exits from the grating reflector and is removed from the system. Cascaded grating reflectors are used in a wavelength division multiplexing (WDM) system. A two section narrow band transmission filter with cascaded gratings.

Optical systems with grating reflector

The present invention provides an optical demultiplexer for demultiplexing an input signal containing a group of optical signals each at a different wavelength into at least two optical signals. The demultiplexer comprises a first optical transfer system comprising an optical circulator having at least three circulator ports for circulating optical signals from one port to the next port in a circulating direction. An input signal containing a group of optical signals is coupled to each at a different wavelength to a first of the circulator ports. A second circulator port optical path is coupled to the second circulator port, the second circulator port being the next circulator port in the circulating direction from the first circulator port. The second circulator port optical path includes a grating reflector for reflecting one of the group of optical signals back to the second circulator port. The reflected optical signal is circulated from the second circulator port to the third circulator port which is the next port in the circulating direction from the second circulator port while the unreflected optical signals from the group of optical signals passes through the grating reflector and continuing on the second circulator port optical path. A second optical transfer system comprising an optical circulator having at least three ports for the input and output of optical signals is optically coupled to the second circulator port optical path of the first optical transfer system at a position downstream of the grating reflector. An output line is coupled to the third circulator port of the first optical transfer system for receiving the reflected optical signal from the second circulator port, i.e., the demultiplexed optical signal.

Optical demultiplexers with grating reflectors

The present invention provides a wavelength division multiplexed optical communication system which includes an optical monitoring channel which is capable of surviving the failure of an optical amplifier. The optical communication system comprises a plurality of optical transmitters which optically communicate with an optical waveguide which carries the multiplexed optical transmission signal. At least one multiple-stage optical amplifier having at least first and second stages is positioned along said optical waveguide. The optical amplifier includes a first and second stages comprising doped fibers having a first gain wavelength band. An optical connecting element having a plurality of ports is positioned between the first and second stages. At least one of an optical monitoring signal transmitter and an optical monitoring signal receiver optical communicates with at least one port of the optical connecting element such that the optical monitoring signal passes through at least one of the first and second stages of the optical amplifier. The optical monitoring signal wavelength is selected to be greater than the longest wavelength of the first gain wavelength band such that the optical monitoring signal is not substantially attenuated by an unpumped optical amplifier. Therefore, in the event of a pump failure to at least a portion of an optical amplifier, the optical monitoring signal will still be transmitted through the that portion of the amplifier without substantial attenuation. In this manner, a wavelength division multiplexed optical communication system is provided with optical monitoring channels which do not occupy a portion of the amplifier gain spectrum and which can survive the failure of an optical amplifier.

Optical monitoring channel for wavelength division multiplexed optical

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

An optical cable television system provides a large channel capacity and uses shared resources, whereby the more expensive hardware is shared over a large number of customers so as to minimize the cost per customer. A video switch network is provided which minimizes the temptation of subscribers to pirate signals since pay per view or on demand signals are provided only upon request of someone within a node corresponding to a neighborhood. An on demand program center continuously plays programs, such as movies, at time-staggered starts such that any subscriber will have only very minimal delays before seeing a particular program which is requested. A tuneable optical filter is provided in order to switch video signals onto an optical fiber going to the node in a particular neighborhood. An arrangement uses in-fiber grating in order to remove and insert different optical frequencies. Local insertion of various program sources, such as local commercials, is accomplished effectively by making such insertion at a relatively high point in the video distribution chain. An interface arrangement to provide on demand video signals to telephone company twisted pair wires is utilized.

Optical cable TV system

Switch and insertion networks in optical cable TV system

The present invention relates to optical amplifier systems which include optical add/drop multiplexing capabilities. The optical amplifier system includes a first optical circulator with at least three circulator ports. An optical transmission fiber optically communicates with the first circulator port for transporting a wavelength division multiplexed (WDM) optical transmission signal. A section of optically amplifying rare-earth doped fiber amplifies the WDM optical transmission signal input to the first circulator port. A wavelength-selecting optical fiber including at least one in-fiber Bragg grating for selectively reflecting an optical signal of a particular wavelength from the WDM optical signal optically communicates with the second circulator port. The optical amplifier system further includes a second optical circulator with at least three optical circulator ports, one of which communicates with the wavelength-selecting optical fiber. Another of the optical ports optically communicates with an optical fiber transmitting optical signals to be added to the WDM optical transmission signal.

Optical amplifier systems with add/drop multiplexing

An optical cable television system provides a large channel capacity and uses shared resources, whereby the more expensive hardware is shared over a large number of customers so as to minimize the cost per customer. A video switch network is provided which minimizes the temptation of subscribers to pirate signals since pay per view or on demand signals are provided only upon request of someone within a node corresponding to a neighborhood. An on demand program center continuously plays programs, such as movies, at time-staggered starts such that any subscriber will have only Very minimal delays before seeing a particular program which is requested. A tuneable optical filter is provided in order to switch video signals onto an optical fiber going to the node in a particular neighborhood. An arrangement uses in-fiber grating in order to remove and insert different optical frequencies. Local insertion of various program sources, such as local commercials, is accomplished effectively by making such insertion at a relatively high point in the video distribution chain. An interface arrangement to provide on demand video signals to telephone company twisted pair wires is utilized.

Optical system with tunable in-fiber gratings

The present invention relates to optical systems having optical amplifiers with flattened gain curves. In one embodiment, the invention comprises an optical amplifier system having an optical input fiber and an optical amplifier device connected to receive optical input signals from the optical input fiber. A directional optical transfer device has a first port connected to receive an initial amplified output from said optical amplifier device. An optical attenuation fiber is connected to a second port of said optical transfer device, and receives the initial amplified output applied to the, first port. The optical attenuation fiber supplies an adjusted amplified output to the second port and includes plural in-fiber gratings and plural attenuators. The in-fiber gratings and attenuators are configured such that an attenuator is disposed between two in-fiber gratings. Each in-fiber gratings reflects a different wavelength of optical energy. An optical output fiber connected to a third port of the directional optical transfer device receives the adjusted amplified output.

Optical amplifiers with flattened gain curves

Method for removing and inserting optical carriers in a WDM 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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Warrington, PA, United States of America

David R Huber