Rockwell Collins, Inc.

Daniel J Esman

Ronald D Esman

Oliver S King

Mark A Laliberte

A system and method for correcting environmental phase drift between signal and reference branches of a photonic analog-digital converter (pADC) with passive remote sampler (PRS) sends a continuous-wave (CW) laser from a base unit through the PRS in a reverse optical path to measure the phase drift. The CW optical signal is converted to an electrical signal from which a phase-error signal indicative of the phase drift is filtered out and sent to a phase shifter. The pADC sends an optical pulse through the PRS in a forward optical path; the signal pulse is phase-modulated according to a received radio frequency (RF) signal of interest. The phase-modulated optical pulses (e.g., signal and reference) are received at the base unit and the phase drift corrected out of the optical pulses via the phase shifter. The corrected optical pulses are demodulated to provide a digital counterpart to the RF signal of interest.

Photonic analog-to-digital converter (pADC) with photonic phase correction

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 is described. The system includes HNLF for generating an optical frequency comb and a single mode fiber for reducing a pulse duration of comb. The system includes a FRM to reflect the light in back propagation through the HNLF and the single mode fiber. Perturbations in a state of polarization caused by the HNLF and the single mode fiber are cancelled between the forward propagation and the backward propagation. The optical frequency comb may then be polarization maintaining without an active component such as a polarization controller and a feedback circuit.

Polarization maintaining parametric optical frequency comb generator

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 system and method for radio frequency (RF) signal processing via photonic local oscillator (LO) phase control generates a set of N optical carriers and M sets of control inputs, each control input including an amplitude and/or phase control for the ncarrier. Each noptical carrier is split into an RF path and M LO paths, the RF path including N electro-optical (EO) modulators for amplitude/phase modulation of each ncarrier per a set of N RF input signals and each mLO path including a set of N EO modulators for amplitude/phase modulation of each ncarrier per the mcontrol input. Demodulators generate M in-phase and quadrature (I/Q) balanced optical outputs based on the multiplexed N combined RF optical outputs and each mset of N combined LO optical outputs. The M I/Q balanced optical outputs are converted to the electrical and then to the digital domain.

Radio frequency (RF) signal processor with photonic local oscillator (LO) phase control

A system and method for analog estimation of a spectral correlation function (SCF) provides a photonic carrier to generate a signal comb and offset comb, each comprising N comb tones separated by respective repetition rates &#x394;F and &#x394;F+&#x3b4;F. The signal and offset combs are amplitude-modulated according to an inbound RF signal of interest and filtered via periodic optical filters to produce a sequence of N Fourier components of the signal comb and N Fourier components of the offset comb, each filtered signal comb component overlapping with a filtered offset comb component. In-phase/quadrature (I/Q) components of the products of each component of the complex conjugate of the filtered offset comb and the overlapping counterpart of the filtered signal comb are generated in an optical receiver and digitized into slices of the SCF at a fixed time instance and center frequency, correlated at various cyclic separations &#x3b1;.

System and method for analog estimation and streaming of a spectral correlation function (SCF)

A computationally efficient real-time photonic cyclic autocorrelation function (CAF) analysis device and method are disclosed. In embodiments, the CAF analyzer generates a photonic carrier which is converted into upper and lower comb signals (comprising a set of N tones) by upper and lower optical frequency comb generators (OFCG), the lower comb signal offset from the upper. An inbound radio frequency (RF) signal is received and modulates the upper and lower comb signals via amplitude modulation. An optical delay line (e.g., ring resonator) introduces a delay into the modulated lower comb signal. The upper and lower comb signals are demultiplexed into their modulated frequency component and sent to a bank of N coherent I/Q receivers, which generate a slice of the CAF for the received RF signal based on the selected delay.

Computationally efficient real time photonic cyclic autocorrelation function (CAF) analyzer device

A system may include: an optical pulse source; fiber optic links; a first optical coupler optically coupled to the optical pulse source; a radiofrequency (RF) source; a phase modulator (PM) optically coupled to the first optical coupler and electronically coupled to the RF source; an interleaving delay optically coupled to the first optical coupler; a second optical coupler optically coupled to the PM and the interleaving delay; a laser; an optical amplifier optically coupled to the laser; a wavelength division multiplexer (WDM) optically coupled to the optical amplifier and the optical coupler; a highly nonlinear fiber (HNLF); an optical filter optically coupled to the WDM via the HNLF; an optical switch optically coupled to the optical filter; and a coherent detector optically coupled to the optical switch via a first optical path and a second optical path, the first optical path including an optical delay.

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Columbia, MD, United States of America

Daniel J Esman