Hrl Laboratories, LLC

Hughes Electronics Corporation

The Directv Group, Inc.

The Boeing Company

Stanislav I Ionov

George C Valley

Anthony Acampora

Rajesh D Rajavel

Robert R Hayes

Hossein H Izadpanah

Yakov Royter

Dennis C Jones

William S Hoult, Jr

Thomas W Ball

Peter Chu

Daniel Yap

Oleg M Efimov

David S Sumida

Metin S Mangir

Irina Ionova, Legal Representative

William C Boling

Sophi Ionova, Legal Representative

Fabrication of a photonic integrated circuit (PIC) including active elements such as a semiconductor optical amplifier (SOA) and passive elements such as a floating rib waveguide. Selective area doping through ion implantation or thermal diffusion before semiconductor epitaxial growth is used in order to define the contact and lateral current transport layers for each active device, while leaving areas corresponding to the passive devices undoped. InP wafers are used as the substrate which may be selectively doped with silicon.

Implantation before epitaxial growth for photonic integrated circuits

A PPM transmitter includes an optical clock generator for generating equally-spaced optical pulses with a sampling period T; an encoder for transforming an incoming waveform U(t) into a linear combination V(t) of U(t) and a delayed output V(t&#x2212;kT) according to a rule V(t)=U(t)+aV(t&#x2212;kT), where k is a positive integer, V(t) is voltage generated by the encoder and a is a coefficient; and an optical delay generator for delaying optical pulses generated by the optical clock generator in proportion to the voltage V(t), such that &#x394;t=bV(t), where b is another coefficient and where &#x394;tis the amount of delay imposed by the optical delay generator. The PPM transmitter functions with a PPM receiver for communicating data without the need to transmit or otherwise provide a clock signal. The PPM receiver decodes an original series of the delayed optical pulses Q(t) and a second series Q(t&#x2212;ckT) delayed by ckT where c is a coefficient.

System, method and apparatus for clockless PPM optical communications

An optical pulse position modulation receiver relying on the gain dynamics in a semiconductor optical amplifier (SOA). Optical PPM signal pulses and periodic optical clock pulses at a different frequency and/or polarization than the signal pulses are coupled into an SOA. Due to the high optical power of the clock pulses, the SOA gain will drop to a small value after each clock pulse. The SOA will then amplify each signal pulse that follows the clock pulse, and the gain will depend on the delay between the signal pulse and the preceding optical clock pulse. The optical output of the SOA can then be converted to an electrical signal by a photodetector.

Method and apparatus for PPM demodulation using a semiconductor optical amplifier

A PPM transmitter includes an optical clock generator for generating equally-spaced optical pulses with a sampling period T; an encoder for transforming an incoming waveform U(t) into a linear combination V(t) of U(t) and a delayed output V(t&#x2212;kT) according to a rule V(t)=a(U(t)+V(t&#x2212;kT)), where k is a positive integer, V(t) is voltage generated by the encoder and a is a coefficient; and an optical delay generator for delaying optical pulses generated by the optical clock generator in proportion to the voltage V(t), such that &#x394;t=bV(t), where b is another coefficient and where &#x394;tis the amount of delay imposed by the optical delay generator. The PPM transmitter functions with a PPM receiver for communicating data without the need to transmit or otherwise provide a clock signal.

System, method and apparatus for clockless PPM optical communication

An all-optical PPM modulator comprises one or more sources of trains of optical control pulses and optical signal pulses, the optical control and optical signal pulses being equally spaced, but differentiated from one another by at least having different optical wavelengths and/or polarizations prior to modulation. An electro-optic modulator, for example, amplitude modulates the control pulses using a signal. A chirped Bragg reflector in an non-linear waveguide receives both the amplitude modulated optical control signal pulses and unmodulated optical signal pulses at an entrance port thereof, the waveguide having a path length selected to achieve temporal overlap of the control and signal pulses in the waveguide. The chirped Bragg reflector is resonant to the optical signal pulses and off-resonant to the optical control pulse. The signal pulses reflect the in chirped Bragg reflector and exit an entrance port thereof while the control pulses either are absorbed or exit an exit port of the chirped Bragg reflector.

All-optical delay generator for PPM communication systems based on a non-linear waveguide with a chirped DBR

A satellite constellation has a plurality of network satellites that form a network. A gateway satellite is disposed adjacent to the network. The gateway satellites receive an optical signal from the network and converts the signal to an electrical signal. The gateway satellite has a sorter and a reshaping circuit for reshaping the electrical signal to form a reshaped signal. The electrical signal is converted back to an optical signal corresponding to the reshaped signal. The optical signal corresponding to the reshaped signal has reduced noise in comparison to the input optical signal. The optical signal is then retransmitted to another satellite.

Global gateway architecture for interconnecting regional satellites into a communication network

Systems and methods are disclosed herein to provide analog-to-digital converter techniques. For example, in accordance with an embodiment of the present invention, an analog-to-digital converter architecture is disclosed that utilizes optical techniques to convert an analog electrical signal to a digital electrical signal.

Analog to digital converter systems and methods

Systems and methods are disclosed herein to provide various optical techniques. For example, in accordance with an embodiment of the present invention, a pulse position modulation discriminator architecture is disclosed for discriminating temporal positions of PPM-encoded optical pulses by converting them from time modulated to frequency modulated signals. As another example, time division multiplexed optical signals may be translated to wavelength division multiplexed optical signals. One or more of the architectures disclosed herein may be implemented, for example, to provide PPM to FM or time to wavelength conversion for receiver or transmitter applications.

Optical pulse position modulation discriminator

Optical techniques are disclosed for improving the range resolution of a radar system. An optical source produces chirped optical pulses whose frequency changes linearly with time, wherein the pulse duration is close to the repetition period (quasi cw radiation). The optical source illuminates the target that scatters a portion of the light back into collecting optics of the ladar's receiver. The delayed back-scattered optical waveform is mixed optically with a reference waveform in a non-linear medium to produce optical radiation at a new frequency. The spectral properties of the non-linearly generated light contains information about the distance to the target. Different approaches that may be chosen for non-linear optical mixing are disclosed including sum and difference frequency generation in non-linear crystals.

High resolution chirped/AM optical FM laser radar

An optical top-hat pulse generator comprising a polarization-maintaining fiber loop and controlled by solitons. A polarization-maintaining coupler launches a continuous wave optical signal into the fiber loop along a principal axis of the fiber loop. Another coupler launches a control pulse into the fiber loop along another orthogonal principal axis. The fiber loop may consist of a plurality of sections of polarization-maintaining fiber spliced together so that the principal axis of one section aligns with the orthogonal principal axis of an adjacent section and the length of each individual section is chosen to achieve equal in magnitude, but opposite in sign group delays between the continuous wave optical signal and the control pulse.

Method and apparatus for optical top-hat pulse generation

An optical demodulator for use as a pulse position demodulator. The demodulator has one or more semiconductor optical amplifiers coupled to receive an optical signal to be demodulated at first end thereof and for receiving optical control pulses at a second end therefore, the optical signal to be demodulated and the optical control pulses counter-propagating in said one or more semiconductor optical amplifiers in order to determine a delay or phase shift there between; and a detector coupled to the one or more semiconductor optical amplifiers for recovering, as an electrical output signal, the delay or phase shift in the optical signal.

Interferometric PPM demodulators based on semiconductor optical amplifiers

An apparatus for directing light beams onto a target comprising a beam splitter for splitting a main beam into a first split beam and a second split beam; a first beam path for the first split beam, the first beam path including a first aperture, a first lens and a second lens; a second beam path for the second split beam, the second beam path including a second aperture, a third lens and a fourth lens; a plurality of mirrors arranged such that the first split beam and the second split beam intersect at the target. An apparatus can also include means for placing a target in the image plane of a first aperture and a second aperture.

Apparatus and method for directing a light beam to a target

A satellite constellation has a plurality of satellites. Each of the satellites has an RF ground link for communicating with a ground station and an optical link for communication with at least one of the plurality of satellites. Each of the satellites has a reconfigurable optical transmitter for sending and receiving data streams. Each reconfigurable optical transmitter has a first optical carrier associated therewith and a reconfigurable optical receiver. The plurality of satellites is arranged to have a first subset of satellites. The first subset of satellites is configured to communicate. The plurality of satellites is reconfigured to have a second subset of satellites having at least one different satellites than that of said first subset. The second subset supercedes the first subset. The second subset of satellites is configured to communicate. Various subset around the globe may form local area networks. The local area networks are preferably optically coupled to form a wide area network.

Growing community of inventors

Calabasas, CA, United States of America

Stanislav I Ionov