Rockwell Collins, Inc.

Infinera Corporation

Little Optics Inc

University System of Maryland

Oliver S King

Raymond Zanoni

Frederick Gorr Johnson

Kim S Jepsen

Wenlu Chen

Brent Everett Little

Sai T Chu

Mark A Laliberte

David M Gill

Marcus Schuetz

John V Hryniewicz

Ronald D Esman

Thomas J Cullen

Daniel J Esman

Han Chi Hsieh

Lance G Joneckis

Wei Chen

Roy R Davidson

Jerzy K Richter

Altin E Pelteku

Timothy J Davidson

Warren P Berk

Philippe Absil

Ping-Tong Ho

Joseph W Heming

A system and method for wavelength detection includes one or more detection stages configured for receiving at least a portion of an optical carrier. Each stage includes a splitter for splitting the signal into two arms. A 90-degree optical hybrid and in-phase (I-channel)/quadrature (Q-channel) differential detectors generate I-channel and Q-channel differential signals based on the hybrid outputs. A gas cell or like multi-point wavelength reference path also receives the input signal and provides a set of reference absorption wavelengths converted into the electrical domain by a reference photodetector. A logic device receives sets of detection signals (including I-channel and Q-channel differential signals and the set of reference wavelengths, all corresponding to a common measurement time) and determines a wavelength of the optical carrier based on an arctangent of a ratio of the Q-channel and I-channel differential signals, mapped to the set of reference absorption wavelengths.

Multi-point self-calibration for broadband optical sensor interrogator

A system and related method for multiple-sensitivity optical phase modulation splits an optical carrier generated by a photonic source into at least two copies and directs the copies (e.g., via optical circulators or polarization rotators) to an electro-optical (EO) phase modulator such that the phase modulator phase-modulates each optical copy according to a received radio frequency (RF) signal of interest based on characteristics distinct to each optical copy (e.g., optical path direction, signal polarization) that provide for phase modulation of each optical copy at a different sensitivity voltage. The variably modified optical copies are directed to a photonic processor for further signal processing in the optical domain.

Multiple-sensitivity optical phase modulator

A system may include an optical phased array, a photodiode array, and a radiofrequency (RF) antenna element array. The optical phased array may be configured to: receive a laser signal from a signal laser; and output an optical beam. Each photodiode may be configured to: receive at least a portion of the optical beam and at least a portion of an optical plane wave beam, wherein the optical plane wave beam is formed based at least on a local oscillator (LO) laser that outputs a laser beam having a different wavelength from the signal laser; and output an electronic signal based on the at least the portion of the optical beam and the at least a portion of the optical plane wave beam. The RF antenna element array may be configured to output an RF beam based on received electronic signals from the photodiode array.

Optical phased array controlled RF phased array

A system and related method for multiple-sensitivity optical phase modulation splits an optical carrier generated by a photonic source into at least two copies and directs the copies through an electro-optical (EO) phase modulator wherein the optical field associated with the optical carrier overlaps with a radio frequency (RF) electrical field associated with a radio frequency (RF) input signal, such that the EO modulator phase-modulates each optical copy according to the RF input signal of interest based on characteristics distinct to each optical copy (e.g., relative strength of, or proximity of the optical carrier to, the overlapping electrical field) that provide for phase modulation of each optical copy at a different sensitivity voltage. The variably modified optical copies are directed to a photonic processor for further signal processing in the optical domain.

A circuit and method for timing-tolerant optical pulse energy electrical conversion receives a current pulse stream converted from an input optical pulse stream (which may be periodic or nonperiodic), converts the current pulse stream to an electrical waveform of voltage pulses and detects each voltage pulse, e.g., by its leading edge. The conversion circuit may include a divider circuit for receiving the electrical waveform, dividing the waveform into a multi-channel output of divided electrical waveforms, and sequential logic circuits for adjusting a width window of each voltage pulse according to an adjustable delay.

Timing-tolerant optical pulse energy conversion circuit comprising at least one sequential logic circuit for adjusting a width window of at least one detected voltage pulse according to a predetermined delay

A non-uniform sampling pADC is disclosed. The pADC may include an optical pulse source configured to generate uniform optic pulses. The pADC may include a non-uniform sampling system. The non-uniform sampling system may include an inter-pulse timing modulation sub-system configured to convert the uniform optic pulses into non-uniform optic pulses. The non-uniform sampling system may include a timing control sub-system configured to control the timing of the optical pulse source. The pADC may include an optical modulator configured to modulate the non-uniform optical pulses. The pADC may include a photodetector configured to convert the modulated non-uniform optic pulses into electronic pulses. The pADC may include a pulse capture assembly configured to capture a pulse amplitude of the electronic pulses and generate sampled radio frequency output pulses. The pADC may include a quantizer configured to quantize the sampled radio frequency output pulses and generate digital radio frequency output signals.

Non-uniform sampling photonic analog-to-digital converter

A wavelength detection system may include one or more wavelength detection stages configured to receive at least a portion of an input light signal, where each stage may include a splitter to split a portion of the input light signal into two arms, a 90-degree optical hybrid, and two differential detectors configured to generate I-channel and Q-channel differential signals based on the outputs from the 90-degree optical hybrid. Further, a free spectral range is associated with an optical path length difference between the two arms of each stage. The system may further include a logic device to receive at least one set of detection signals including I and Q channel differential signals associated with different free spectral ranges and determine the wavelength of the input light signal based on an arctangent of a ratio of the Q-channel and I-channel differential signals for at least one set of detection signals.

Wide range optical wavelength fast detection for narrowband signal

An integrated photonics monopulse comparator includes an array of squinted monopulse elements, each monopulse element producing an RF signal in response to a received inbound signal and each RF signal having a squinted RF voltage. The comparator includes a laser source for producing a wavelength division multiplexed (WDM) optical signal comprising multiple components having discrete wavelengths. The component signals may be multiplexed and demultiplexed and routed through cascading optical phase modulators, each phase modulator connected to a monopulse element and capable of modulating a component signal according to the voltages of the RF signals produced by the corresponding monopulse element. The resulting modulated component optical signals undergo coherent photodetection by arrays of paired photodiodes, each pair receiving component signals of like wavelength. The output signals of each array are proportional in voltage to sums and differences from which arrival angles of the inbound signal may be calculated.

Photonic monopulse comparator

A method of performing optical serial-to-parallel conversion of an optical signal includes performing phase modulation of the optical pulse stream and outputting a phase-modulated optical signal as a result thereof. The method also includes performing optical switching of the phase-modulated optical signal by optical switches connected to each other in a series relationship on a signal path. The method further includes performing optical switching of a reference optical clock signal by optical switches connected to each other in a series relationship on a reference path. The method also includes performing, by I/Q demodulators, I/Q demodulation of the optically switched phase-modulated optical signal respectively output by one of the optical switches on the signal path at timings corresponding to the optically switched reference optical clock signal respectively output by one of the optical switches on the reference path, in which the I/Q demodulators respectively output I and Q demodulated signals as a result thereof. The method further includes performing, by pairs of gated photodetectors respectively connected to the I/Q demodulators, photodetection of the I and Q demodulated signals respectively output of the I/Q demodulators.

Optical sample and hold system and method

A method and related system for linearizing a photonic ADC sampling system of an ELINT receiver includes modulating optical pulse trains of varied pulse amplitudes based on a generated ramped-voltage calibration signal. The modulated pulse trains are demodulated into I/Q components to generate signal constellations. Equivoltage radials are defined by points of the signal constellations sharing a common calibration voltage and a common phase angle of the modulator. A lookup table is generated by mapping the signal constellations and equivoltage radials to a coordinate system to determine, for each coordinate bin, a corresponding pulse amplitude and phase angle. The generated lookup table may be used to correct nonlinear distortions in recovered output signals, preserving high-ENOB performance and increasing the dynamic range of the receiver.

Linearization of photonic analog-digital converter (pADC) system based on multi-dimensional quantization (MDQ)

A photonic analog to digital converter (pADC) includes an electronic I/Q generator, an optical sampler, and an optical detector. The electronic I/Q generator is configured to receive an RF signal and to generate an electronic in-phase signal I and an electronic quadrature-phase signal Q based on the received RF signal. The optical sampler includes one or more optical intensity modulators configured to receive the electronic I and Q signals from the electronic I/Q generator, and to modulate optical pulses to provide modulated optical I and Q signals based on the received electronic I and Q signals from the electronic I/Q generator. The optical detector includes a plurality of photodetectors, and is arranged to receive the modulated optical I and Q signals from the optical sampler and to convert the modulated optical I and Q signals into modulated electronic I and Q signals.

Photonic direct sampling digital receiver

A photonic processor can include a first input for a phase-modulated optical pulse signal, a second input for an optical reference signal, and a plurality of states. Each stage is configured to receive the phase-modulated optical pulse signal and a phase-delayed version of the optical reference signal. The phase-delayed version is phase-delayed in accordance with a phase position of the stage. Each stage is comprised of a reference path, a signal path, a coupler and a balanced photo detector. The coupler receives the phase-modulated optical pulse signal and provides as stage phase-modulated optical pulse signal to the signal path. The signal path is coupled to a first input of the balanced photo detector. The coupler also receives the phase-delayed version and provides a stage optical reference signal to the reference path. The reference path is coupled to a second input of the detector. The detector provides an electronic output signal corresponding to a phase relationship.

Optical conversion system and method with multiple phase processing

A method of and system of processing a phase-modulated optical signal includes performing, by demodulators, demodulation of the phase-modulated optical signal and outputting optical demodulated signals. The processing further includes performing, by pairs of gated photo detectors respectively connected to the I/Q demodulators, photo detection of the demodulated signals. The processing further tracks and holds electronicversions of the demodulated signals with a track and hold amplifier.

Optically interleaved photonic analog to digital converters

A photonic processor can include a first input for an amplitude-modulated optical pulse signal, a second input for an optical reference signal, and a plurality of stages. Each stage is configured to receive the amplitude-modulated optical pulse signal and a version of the optical reference signal. The version is amplitude attenuated in accordance with a position of the stage. Each stage is comprised of a reference path, a signal path, two couplers and a balanced photo detector. The first coupler receives the pulse signal and provides as stage pulse signal to the signal path coupled to a first input of the detector. The second coupler receives the version and provides a stage optical reference signal to the reference path coupled to a second input of the detector. The detector provides an electronic output signal corresponding to an amplitude relationship.

Optical conversion system and method with multiple amplitude processing

A system and method of digitizing an analog signal without an amplitude channel is disclosed. The system and method includes receiving an analog signal comprising a voltage v(t) and a frequency f1, producing a series of optical pulses at a sampling frequency f2 with a pulsed laser, splitting the series of optical pulses into a first optical signal and an optical reference signal, phase modulating the first optical signal with the analog signal to produce a sampled optical signal such that phase shifts between adjacent samples in the sampled optical signal does not exceed &#x3c0; radians, and receiving the sampled optical signal and the optical reference signal at a photonic signal processor.

Growing community of inventors

Frederick, MD, United States of America

Oliver S King