Northrop Grumman Systems Corporation

Other

James M Cicchiello

John Featherston

Christopher A Archer

Curtis J Harkrider

Frederick D Bean

David A Gallagher

Kenneth E Kreischer

Gerald Pray Griffith

Ronald K Meyer

Michael A Davis

Jean Christopher Shelton

Hao C Tran

An optical communications system includes a modulator/demodulator (modem) to transmit outgoing communications data and to receive incoming communications data in a transceiver. A main detector is coupled to the modem to convert an optical signal representing the incoming communications data to an electrical signal for the modem. An adaptive data rate processor monitors the electrical signal from the main detector to determine a current power level for the optical signal. The adaptive data rate processor dynamically adjusts a data rate of the modem based on the determined current power level of the optical signal.

Optical transceiver with variable data rate and sensitivity control

A system includes a detector array having a plurality of level detectors to monitor an optical input signal. Each level detector of the detector array operates in a different operating range, and each operating range for each level detector has a different saturation level and a different cutoff level based on a power level of the optical input signal. A controller monitors the plurality of level detectors of the detector array to detect a present power level for the optical input signal by selecting the operating range that is associated with the level detector operating between its saturation level and its cutoff level.

Optical receiver sensitivity system

A free-space optical (FSO) transceiver can include a link predictor configured to estimate conditions for an FSO link over a window of time in the future. The FSO transceiver can also include a scheduler configured to assign outgoing packets to blocks of time in the window of time based on quality of service (QoS) parameters of each of the outgoing packets and on conditions in each block of time in the window of time.

Free space optical transceiver

A free-space optical (FSO) transceiver can include a transmission protocol configured to encapsulate outgoing network packets in by employing a reliable ordered protocol that relies on retransmission of lost data to form outgoing encapsulated packets. The transmission protocol controller can be configured to employ a congestion algorithm that optimizes throughput over a lossy link. The FSO transceiver can also include a transmitter configured to provide an output optical signal corresponding to the outgoing encapsulated packets over an FSO link.

Transmission protocol controller

A beam-steering element made of a more optically-active material, potassium tantalate niobate, with an improved diffraction efficiency, having a plurality of electrode layers and one electro-optic crystal layer interposed between every two adjacent electrode layers. Each electro-optic crystal layer and the electrode layer adjacent thereto have an aspect ratio of about 1:1. The electrode layers and the electro-optic crystal layers are interposed between two substrates. Preferably, the substrates are transparent to an incoming beam to be modulated by the electro-optic crystal layer.

Electro-optic crystal, diffraction-based, beam-steering element

An optical tag, having a photo-detector, a controller, a piezoelectric translator, a battery and a retro-reflective tape. The photo-detector is responsive to an optical energy at a predetermined wavelength, and the controller is connected to the output of the photo-detector. The piezoelectric translator connected to controller is also connected to the battery when the photo-detector responds to the optical energy. The retro-reflective tape is directly mounted on the piezoelectric translator. When the connection between the piezoelectric translator and the battery is established, a pulse is generated and applied to the retro-reflective tape. Therefore, the optical energy incident on the retro-reflective tape is modulated by the pulse and retro-reflected by the retro-reflective tape.

Dynamic optical tag

An optical head is provided for a free space optical communications system. The optical head is utilized for transmitting and receiving modulated infrared laser beams. The optical head includes an optical amplifier, a circulator, an ultrafine-steering element, a fine-steering element, a course-steering element, and a fine track sensor. Additionally, a method is provided for facilitating airborne free space optical communications between an airborne host platform and a link platform. Each platform has an optical head which transmits and receives data via modulated infrared laser beams, wherein the host includes at least an optical head having a fine, coarse, and ultrafine steering element configured in a cascaded three-tier steering element architecture.

Airborne free-space-optical system utilizing three-tier, ultrafine steering

A phase distortion device/method has been developed to improve images. A wave source generates waves, which stimulate the reflection and/or emission of narrow-band waves from an object of interest or a nearby object. The phase distortion of the narrow-band waves is used to obtain an impulse response function, which is then used to correct an image formed by illumination waves.

Real-time correction of phase distortion

An integrated optical parametric oscillator, having an optical parametric oscillation region to convert a pump source into a signal beam and an idler beam, and a fine-steering region to adjust optical path of the signal beam in order to finely select a required wavelength component of the signal beam. The optical parametric oscillator is contoured with a plurality of exterior planes with specific reflective characteristics to form a resonator of the idler beam while reflecting and diffracting the signal beam with a desired wavelength.

Integrated narrow-line tunable optical parametric oscillator

An electro-optic crystal based beam-steering device preferably based on KTN, having a first deflector and a second deflector. The first deflector has a pair of substrates each having a plurality of first electrode lines extending along a first direction and a plurality of electro-optic crystal modulators interposed between the first electrode lines. The second deflector has a pair of substrates each having a plurality of second electrode lines extending along a second direction and a plurality of electro-optic crystal modulators interposed between the second electrode lines. The first direction is orthogonal to the second direction.

Architecture for large-FOR EO-crystal-based agile beam steering

An electronically modulated prism, having a bulk crystal, a plurality of electrode pads formed on a top surface of the bulk crystal, and a common electrode formed on a bottom surface of the bulk crystal. The bulk crystal is optically isotropic with zero electric field applied thereto and optically anisotropic when subjected to a non-zero electric field. More specifically, the bulk crystal between each of the electrode pads and the common electrode has an index of fraction altered proportionally to the electric field applied thereto, such that an incident beam propagate through the crystal is modulated with an accumulated phase shift.

Growing community of inventors

Cary, IL, United States of America

James M Cicchiello