Trw Limited

Northrop Grumman Systems Corporation

The Aerospace Corporation

Donald Glen Heflinger

Lee O Heflinger

Todd E Humes

Stephen John Brosnan

Ramon Coronel

James M Zamel

Daniel W Lam

Arthur B O'Connor

Karen A Fucik

Peter S Yoon

John D Hyde

Michael G Wickham

Kiet D Ngo

Raymond K DeLong

Gerald W Holleman

Dennis M Hall

Richard B Sherwood

Phillip D Hayashida

David W Y Lee

Peter M Tanner

Jeffrey S Bauch

An optical communications terminal including a polarizing element responsive to a first linearly polarized optical beam and rotating the first linearly polarized optical beam in a first linear direction, a beam separator responsive to and passing the first linearly polarized optical beam, and a circular polarizing element responsive to the first linearly polarized optical beam from the beam separator and circularly polarizing the first linearly polarized optical beam for transmission, where the circular polarizing element is switchable between two orthogonal switching states. The terminal receives a circularly polarized optical beam from another terminal and linearly polarizes the circularly polarized optical beam from the other terminal in a second linear direction that is orthogonal to the first linear direction and the beam separator directs the circularly polarized optical beam from the other terminal in a direction away from the polarizing element.

Optical communications terminal

An optical communications system including two communications terminals in communication with each other using optical signals having the same wavelength. Both terminals include a half-wave plate polarizer for rotating linearly polarized optical signals and a quarter-wave plate polarizer for circularly polarizing the optical signals. The quarter-wave plate polarizers are oriented 90&#xb0; relative to each other so that circularly polarized optical signals sent from one terminal to the other terminal are linearly polarized 90&#xb0; relative to a transmission polarization orientation to be separable from the transmitted optical signals by a beam splitter.

Optical free space communication apparatus using polarization

Apparatus for isolating transmit and receive optical beams having a common wavelength to ensure genderless interoperability in an optical communication system comprises a transmit path that propagates a transmit optical beam at a particular base wavelength and a receive path that propagates a receive optical beam at the same particular base wavelength wherein at least a portion of the receive path is separate from the transmit path. The apparatus further comprises an annular mirror having a receive beam region and a center aperture and the transmit path includes a steering mirror and the receive path also includes the steering mirror. The steering mirror has a single surface that reflects an entirety of the transmit optical beam transmitted along the transmit path and the single surface of the steering mirror reflects an entirety of the receive optical beam received along the receive path. A method of isolating transmit and receive optical beams in an optical communication system is also disclosed.

Spatial transmit/receive isolation apparatus and method for optical communication systems

An integrated circuit device includes a thin semiconductor layer disposed on a surface of a wafer, a plurality of wafer-scale integrated (WSI) circuits formed on the semiconductor layer, and a node formed on the semiconductor layer that provides an optoelectronic interface to an axial optical data bus for high-speed optical interconnectivity between the WSI circuits and other external devices interconnected to the optical data bus.

Large multi-function integrated circuit device

An optical communication system ( ) is provided for transmitting a multi-rate data signal between a transmitter ( ) and a receiver ( ) in a power efficient manner. The optical communication system ( ) includes an optical source ( ) that supplies an optical carrier signal; an encoder ( ) that receives and encodes a data signal; an external phase modulator ( ) that modulates the optical carrier signal with the encoded data signal, such that the modulator ( ) varies the duty factor of the modulated optical signal based on the encoded data signal; and an optically saturated erbium doped fiber amplifier ( ) that amplifies the modulated optical signal prior to transmission by the transmitter ( ). In accordance with the present invention, the modulation scheme of the optical communication system ( ) varies the duty cycle of the modulation to attain power efficiency during periods of low data demand. In an alternative modulation scheme, data bits are encoded using bi-phase mark encoding and are transmitted in variable-length blocks.

Multi-rate variable duty cycle modem for use in an optical communication system

An optical communication system uses a radio frequency (RF) signal for communicating an analog communication signal. It comprises an optical transmitter and receiver. The transmitter generates a reference light beam, generates a shifted light beam that is shifted in frequency by the RF frequency, and responds to the analog communication signal and produces a communication light beam having a phase modulation corresponding to the analog communication signal. The optical receiver comprises first means to interferometrically combine the reference light beam with the shifted light beam to provide a first heterodyne signal, second means responsive to the first heterodyne signal to produce a first electrical signal at the optical beat frequency corresponding to the RF, third means to interferometrically combine the communication light beam with the shifted light beam to provide a second heterodyne signal including information regarding the state of phase of the communication light beam, fourth means responsive to said second heterodyne signal to produce a second electrical signal at the optical beat frequency corresponding to the RF and with a phase corresponding to the state of phase of the communication light beam, and fifth means responsive to said first and said second electrical signals to provide an output signal that has a linear correspondence to the state of optical phase of said communication light beam and the analog communication signal. Also disclosed are the transmitter and the receiver.

Optical communication system with phase modulation

A broadcast optical communication system is disclosed. It comprises an optical waveguide having a plurality of gratings. A first grating is disposed at a first node and couples light impinging normally into the waveguide, propagates coupled light bi-directionally through the waveguide and emits a portion of the coupled light at a second grating in a direction normal thereto. An optical source is disposed proximate the first node for transmitting light normally to the first grating and an optical detector is disposed proximate the second node for detecting the normally emitted light. In another embodiment multiple optical waveguides and source-detector pairs are employed in a parallel data architecture to provide multiple channel broadcast communication.

Broadcast optical communication system employing waveguide having grating normal to sources and detectors

An optical communication system uses a radio frequency (RF) signal for communicating an analog communication signal. It comprises an optical transmitter and receiver. The optical transmitter comprises means for generating a first reference light beam, and means responsive to the analog communication signal to produce a communication light beam having phase modulation corresponding to the analog communication signal. The optical receiver comprises first means responsive to the reference light beam and the RF signal to develop a shifted light beam that is shifted in frequency by the RF frequency, second means to interferometrically combine the communication light beam with the shifted light beam to provide a heterodyne signal including information regarding the state of phase of the communication light beam, third means responsive to said heterodyne signal to produce an electrical signal at the optical beat frequency corresponding to the RF and with a phase corresponding to the state of phase of the communication light beam, and fourth means responsive to the RF signal and the electrical signals to provide an output signal that has a linear correspondence to the state of optical phase of the communication light beam and the analog communication signal. The optical transmitter and optical receiver are also invented.

Linear analog optical communication system with two transmitted beams and phase modulation

An apparatus and a method for stabilizing an optical interferometer using two optical signals that differ in wavelength by a factor of two is disclosed. The optical interferometer has an optical path length that is tunable. It develops a first interference pattern when the original optical signal is present and the optical path length is a prescribed value. When a second optical signal that has a wavelength that is twice or one-half of the original is dithered and a path length adjustment drive signal is present the interferometer develops a second interference pattern when the optical path length is the prescribed value. An optoelectronic detector is responsive to the second optical interference pattern and develops an electronic feedback signal when the second interference pattern is not present. Accordingly, a feedback circuit produces the optical path length adjustment drive signal, which serves to change the optical path length until it reaches the prescribed value to restore both the second interference pattern and the first interference pattern, thereby tuning the optical interferometer.

Apparatus and method employing two optical signals for stabilizing an optical interferometer

An optical communication system, using a radio frequency (RF) signal for communicating an analog communication signal, includes an optical transmitter and an optical receiver. The optical transmitter generates a reference light beam, generates a phase modulated communication light beam by phase modulating the reference light beam with the analog communication signal, polarizes a portion of the reference light beam and combines the polarized reference light beam and the phase modulated communication light beam. The optical receiver separates the reference light beam and the communication light beam, develops a shifted light beam that is shifted in frequency by the RF frequency, interferometrically combines the communication light beam with the shifted light beam to provide a heterodyne signal including information regarding the state of phase of the communication light beam, uses the heterodyne signal to produce an electrical signal at an optical beat frequency corresponding to the RF and with a phase corresponding to the state of phase of the communication light beam, and derives from the RF signal and the heterodyne signal an output signal that has a linear correspondence to the state of optical phase of the communication light beam and the analog communication signal.

Optical communication system with a single polarized, phase modulated transmitted beam

A fully optical converter for converting an analog signal into a digital signal includes an amplitude to optical wavelength converter for converting the analog signal into an optical signal which varies in wavelength in accordance with an amplitude of the analog signal, a splitter for applying the optical signal over a desired number of light paths, an interferometer connected to each of the light paths, unequal path lengths in each leg of the interferometers to allow optical interference to deliver a complementary sinusoidal transfer function to the optical signal to generate two complimentary output signals and a dual detector connected to each of the interferometers for generating a digital bit in response to the two complimentary output signals, wherein each of the digital bits together form a parallel digital word. The fully optically based converter is automatic and independent of interactive techniques, thus providing for an expedited conversion rate.

Fully optical analog to digital converters with complementary outputs

An apparatus using an optical signal for actively tuning an optical interferometer without introducing any dither in its optical path length. The apparatus comprises a dither generator, means applying a portion of the dithering signal to the optical signal so as to provide an optical signal having a varying wavelength, an optical interferometer having a path length that is tunable and that responds to the optical signal having a varying wavelength and a path length adjustment drive signal and develops a first interference pattern when said path length is a prescribed value and a second interference pattern when the optical path length is changed, photodetector means responsive to the optical interference pattern and operative to develop an electronic feedback signal when the first interference pattern is not present, and a synchronous detection lock-in amplifier that is responsive to a portion of the dithering signal and the electronic feedback signal and operative to produce the optical path length adjustment drive signal. The drive signal changes the optical path length until it reaches the prescribed value, thereby producing the first interference pattern and tuning the optical interferometer. also a method of using an optical signal for tuning an optical interferometer by adjusting its optical path length without introducing dither into the path length is invented.

Apparatus and method for tuning an optical interferometer

A high average power fiber-laser system comprises a master oscillator for generating a primary laser signal; a beam splitter array for splitting the primary laser signal into N secondary laser signals; an optical frequency shifter for shifting the frequency of the primary laser signal; a phase modulator array for providing phase compensation of the N secondary laser signals; N single-mode dual clad fiber amplifiers for amplifying the N secondary laser signals and generating an output beam; a beam sampler for sampling the wavefront of the output beam, defining an array of sampled signals; means responsive to the array of sampled signals for interferometrically combining the array of said sampled signals and the shifted primary laser signal into an array of heterodyne optical signals, each having a phase that corresponds to the state of phase of the array of sampled signals; and means responsive to the array of heterodyne optical signals for providing a plurality of feedback signals to the phase modulator array that are linearly proportioned to the state of phase over at least one wave to provide phase compensation of the secondary laser signals. This includes digital dividers for dividing electrical signals by a selected integer and an exclusive OR gate for providing a pulse train having a duty cycle that reflects the phase to be compensated.

High average power fiber laser system with high-speed, parallel wavefront sensor

A wafer-scale module includes a plurality of stacked wafers, each having a thin semiconductor layer disposed on a surface of the wafer, a plurality of wafer-scale integrated (WSI) circuits formed on the semiconductor layer and a plurality of nodes formed on the semiconductor layer. Each node provides an optoelectronic interface to an axial optical waveguide for high-speed optical interconnectivity between the WSI circuits and other integrated wafer circuit devices of the stack. A top plate is included and is disposed on the plurality of stacked wafer devices. A base plate, included for purposes of thermal dissipation, is disposed opposite the top plate such that the plurality of stacked wafers are sandwiched between the top plate and the base plate and all are assembled.

Pseudomonolithic wafer scale module

A wavelength division multiplexed optical communication system comprises an optical waveguide having a plurality of gratings, each defining a node. A first grating is disposed at a first node couples impinging light at a plurality of preselected wavelengths into the waveguide. The coupled light propagates through the waveguide and is emitted at a second and at a third grating in directions corresponding to each of the preselected wavelengths. A plurality of optical sources is arranged proximate the first node, each source transmitting an optical signal at a preselected wavelength that differs from that transmitted by the other sources and arranged to transmit light to the first grating. Optical detectors are disposed proximate the second and the third nodes, and positioned in directions corresponding to the emitted light. Thus each detector detects one of the preselected wavelengths. This constitutes a broadcast type of communication system.

Growing community of inventors

Torrance, CA, United States of America

Donald Glen Heflinger