Gte Laboratories Incorporated

Raytheon Company

Other

William J Miniscalco

Gary D Coleman

Leonard J Andrews

Irl W Smith

Elliot G Eichen

John F Silny

Thomas E Peters

Romano G Pappalardo

Alexander Lempicki

Norman A Sanford

Jagannath Chirravuri

C Thomas Hastings, Jr

Maciej D Makowski

James McSpadden

Robert D O'Shea

Ta-sheng Wei

Karen Lee

Howard L Waldman

Stephen D Nordel

Evan J Matthews

Barbara A Thompson

A system includes a network having multiple network nodes each configured for free-space optical communication. Each network node includes one or more apertures through which optical beams are transmitted and received over optical links. The optical links include (i) a traffic link that transports higher-rate traffic between nodes and (ii) an acquisition/tracking link that transports lower-rate signals used to establish and maintain location knowledge of other nodes. Each network node also includes a network processor configured to determine one or more backup paths through the network. Each network node further includes a beam steering unit configured to redirect an optical beam from the traffic link onto the acquisition/tracking link to create a backup traffic link.

Free-space optical network with agile beam-based protection switching

An electro-optical payload for free space optical communication includes: a plurality of optical beam expanders, each for receiving a respective optical signal; an optical cross-connect switch for directing respective optical signals to respective optical output signals; an electrical-to-optical conversion circuit coupled to an input of the optical cross-connect switch for converting an electrical signal to an optical signal for inputting to the optical cross-connect switch; an optical-to-electrical conversion circuit for converting an optical signal output from the optical cross-connect switch to an electrical signal; and an electrical regeneration circuit including a second optical-to-electrical conversion circuit coupled to an output of the optical cross-connect switch and a second electrical-to-optical conversion circuit coupled to an input of the optical cross-connect switch for converting an optical out signal of the optical cross-connect switch to an electrical signal.

Electro-optical payload for high-bandwidth free space optical communications

The disclosure provides a practical system and methods for implementing an adaptive free-space optical network with a high-connectivity, dynamic mesh topology. The network can have operational characteristics similar to those of RF mobile ad-hock networks. Each node has one or more optical terminals that may utilize space-time division multiplexing, which entails rapid spatial hopping of optical beams to provide a high dynamic node degree without incurring high cost or high size, weight, and power requirements. As a consequence the network rapidly sequences through a series of topologies, during each of which connected nodes communicate. Each optical terminal may include a plurality of dedicated acquisition and tracking apertures which can be used to increase the speed at which traffic links can be switched between nodes and change the network topology. An RF overlay network may be provided to act as a control plane and be used to provide node discovery and adaptive route planning for the optical network.

Free-space optical mesh network

A laser relay module for free space optical communications including an optical telescope for receiving and transmitting optical beams; an optical diplexer for separating transmitting and received optical beams; an optical amplifier; a modulated beacon laser for line of sight control of a plurality of communicating remote network nodes; a beacon beam detector for detecting an incoming beacon optical beam for line of sight control of the optical telescope and receiving data from other network nodes; and means for inserting an output of the modulated beacon laser into the optical telescope for transmission to another network node, and for transporting the incoming beacon optical beam to the beacon detector.

Laser relay for free space optical communications

Various embodiments provide a satellite communication system including a first transceiver and a second transceiver geographically fixed on the earth, and a first satellite configured to communicate with the first transceiver through a first link. The system further includes a second satellite configured to communicate with the second transceiver through a second link and communicate with the first satellite through a laser communication crosslink. The first satellite and the second satellite are at a low earth orbit or medium earth orbit below the geostationary earth orbit of approximately 36000 km.

Extensible high bandwidth global space communication network

A space-time division multiple-access (STDMA) laser communications (lasercom) system and related techniques. The STDMA system includes a plurality of remote nodes and an STDMA access node which uses precise electronic beam steering and beacons to provide access to each of a plurality of remote access nodes by means of both space and time-division multiple access.

Space-time division multiple-access laser communications system

A host acting as an optical emitter and a process of making the same for the .sup..about. 1.3 .mu.m to .sup..about. 1.55 .mu.m spectral region utilized in optical communications is disclosed. The host is Cr-activated willemite (Zn.sub.2 SiO.sub.4). Efficient band-emission at room temperature, with peak at 1.42 .mu.m, is observed on exiting the material in the near infrared, typically at 730 nm and 829 nm.

Optical emitter for amplification and process for making same

A fiber optic amplifier is disclosed utilizing a doped fiber to provide amplification through stimulated emission. The doped fiber is simultaneously pumped by multiple pump lasers generating optical waves of differing wavelengths. The optical waves from the lasers are combined using a wavelength division multiplexer before introduction into the doped fiber. The use of multiple pump lasers decreases the power requirements of each laser, reduces the cost of the amplifier, and increases reliability without compromising the gain of the amplifier.

Fiber amplifier with multiple pumps

A fiber optical Y-junction device includes a l.times.N optical fiber coupler connected to N fiber optic amplifier module structures constructed from a doped optical fiber. When the optical Y-junction structure contains a fiber optic amplifier, the fiber optical Y-junction device is operable as either a modulator or lossless power divider. A nonblocking optical switch is constructed by coupling M.times.l optical fiber couplers to the outputs of the fiber optic amplifier module structures utilizing the fiber optical Y-junction.

Fiber optical Y-junction

Glass compositions for high efficiency erbium.sup.3+ -doped optical fiber lasers, amplifiers and superluminescent sources are optimized for pumping by high power solid state lasers in the vicinity of 800 nm to provide amplified signals in wavelengths between 1.5 and 1.7 microns, a principal telecommunications window. A number of suitable host glasses for doping with erbium 3+ are identified wherein the excited state absorption/ground state absorption intensity ratio calculated at 800 nm is 1.00 or less.

Glasses for high efficiency erbium (3+) optical fiber lasers,

A laser has been made using a Nd.sup.3+ -doped fluoro-zirconate heavy metal fluoride (HMF) glass multimode fiber which lases in a range equal to or greater than 1.32 micrometers. The fiber laser was made for forming a glass fiber from a core glass composition comprising 52.8 mole % ZrF.sub.4, 19.9 mole % BaF.sub.2, 2.5 mole % LaF.sub.3, 3.0 mole % AlF.sub.3, 19.9 mole % NaF, 0.4 mole % InF.sub.3, and 1.5 mole % NdF.sub.3 the active dopant and the composition of the cladding glass comprises 39.6 mole % ZrF.sub.4, 17.9 mole % BaF.sub.2, 4.0 mole % LaF.sub.3, 3.0 mole % AlF.sub.3, 21.9 mole % NaF, 0.4 mole % InF.sub.3, and 13.2 mole % HfF.sub.4.

Fluorozirconate fiber optic laser

Apparatus employing a light beam to affect another light beam. A primary beam of linearly polarized monochromatic light is directed on an element of chromium chalcogenide spinel magnetic semiconductor, specifically single crystal CdCr.sub.2 Se.sub.4. A control beam of monochromatic light is selectively elliptically polarized and directed at the element. As the light beams traverse the same path through the element the circularly polarized control beam interacts with the element thereby changing the effect of the element on the linearly polarized primary beam to rotate the plane of linear polarization of the primary beam. A linear polarization analyzer receives the primary beam from the element and passes, blocks, or diverts light depending upon the plane of linear polarization of the incident light.

Growing community of inventors

Sudbury, MA, United States of America

William J Miniscalco