Abstract: A system and method are provided for distributed acoustic sensing in a multicore optical fiber. The system includes a transmitter for simultaneously propagating a sequence of M light pulses through the multicore optical fiber using a spatial mode selected from a set of N spatial modes provided by a spatial mode selector for the transmitter that is coupled to an input to the multicore optical fiber, with M and N being respective integers greater than one. The system further includes a receiver for receiving the sequence of M light pulses at an output of the multicore optical fiber and detecting an environmental perturbation in the multicore optical fiber based on an evaluation of a propagation of the sequence of M light pulses through the multicore optical fiber.

Abstract: Methods and systems for Brillouin optical time-domain reflectometry include optically filtering out non-Brillouin signals reflected from a fiber. Brillouin signals reflected from the fiber are coupled with a local oscillator to produce a Brillouin shift signals. The Brillouin shift signals are converted to an electrical domain using a photodetector. The electrical Brillouin shift signals are converted to a digital domain using a low-speed analog-to-digital converter that has a sampling rate below a Nyquist rate sufficient to fully resolve the electrical Brillouin shift signals.

Abstract: A computer-implemented method for authenticating an access point attempting to access a wireless network is presented. The computer-implemented method includes receiving an authentication challenge from the access point, analyzing the authentication challenge at a wireless node by using an optical chaos generation module having an optical section and a radio frequency (RF) section to facilitate reproducibility, unpredictability, and unclonability of challenge-response pairs, and transmitting an authentication response to the access point.

Abstract: An unrepeatered transmission system includes a receiver coupled to a receive span; a transmitter coupled to the receive span; and a plurality of cascaded amplifiers in the receive span with dedicated fiber cores to supply one or more optical pumps from the receiver to each amplifier, wherein the plurality of cascaded amplifiers increase system reach by increasing the length of a back span in an unrepeatered link.

Abstract: A system and method are provided for distributed acoustic sensing in a multicore optical fiber. The system includes a transmitter for simultaneously propagating a sequence of M light pulses through the multicore optical fiber using a spatial mode selected from a set of N spatial modes provided by a spatial mode selector for the transmitter that is coupled to an input to the multicore optical fiber, with M and N being respective integers greater than one. The system further includes a receiver for receiving the sequence of M light pulses at an output of the multicore optical fiber and detecting an environmental perturbation in the multicore optical fiber based on an evaluation of a propagation of the sequence of M light pulses through the multicore optical fiber.

Abstract: A system and method are provided for distributed acoustic sensing in a multimode optical fiber. The system includes a transmitter for simultaneously propagating a sequence of M light pulses through the multimode optical fiber using a spatial mode selected from a set of N spatial modes provided by a spatial mode selector for the transmitter that is coupled to an input to the multimode optical fiber, with M and N being respective integers greater than one. The system further includes a receiver for receiving the sequence of M light pulses at an output of the multimode optical fiber and detecting an environmental perturbation in the multimode optical fiber based on an evaluation of a propagation of the sequence of M light pulses through the multimode optical fiber.

Abstract: Systems and methods are disclosed for receiving data by radio frequency (RF) mixing to down-convert in-phase and quadrature parts of a photo-detected electrical RF band signal to baseband for data conversion; controlling a mixing phase of a electrical local oscillator (LO) at one or more RF mixing modules; selecting one of the RF sub-bands to be down-converted to baseband after coherent photo-detection; and performing RF sub-band de-multiplexing for ultra-wide band optical digital coherent detection.

Abstract: Systems and methods are disclosed for data communication by performing RF sub-band multiplexing and demultiplexing by cascading a radio-frequency (RF) mixing module and optical dual-polarized (DP) QPSK modulator forhybrid RF/optical IQ modulation; and performing intra-transceiver optical superchannel switching through the RF sub-band multiplexing.

Abstract: Aspects of the present disclosure are directed to the mitigation of multi-path interference from quasi-single-mode fiber using hybrid span configuration and digital signal processing wherein a hybrid span of quasi-single mode fibers and single-mode fibers are used to configure the hybrid span. Additional aspects are directed to introducing a low-baud rate sub-banding signal to reduce the number of DD-LMS taps required when compensating the multi-path interference as the low-baud rate signal requires fewer taps to cover a given range of MPI as compared to a high-baud rate signal. Finally further aspects are directed to an ALMS equalizer which further reduces the number of equalizer taps by shifting its center tap towards the right if higher-order modes transmit slower than a fundamental mode, otherwise the center tap is shifted to the left.

Abstract: Systems and methods for optical communication are disclosed that include communicating data using one or more transceiver pairs coupled to a spatial-multiplexer (S-MUX); performing bi-directional transmissions over an elliptical core optical fiber to a spatial-demultiplexer (S-DEMUX) using spatial modes to communicate data in either direction between two transceiver pairs with low crosstalk and without optical circulators or wavelength-division multiplexing (WDM); and communicating data from the S-DEMUX with g one or more transceiver pairs.

Abstract: A system for centralized automatic bias control for a plurality of modulators, including a coupler for coupling output of each of the plurality of modulators to generate a combined modulator output. A pilot insertion device inserts a pilot tone into each of the plurality of modulators such that a different pilot tone frequency is inserted for each of the plurality of modulators. A monitoring device iteratively monitoring power (Pt) of each inserted pilot tone over time to determine whether a current modulator bias is optimal for each of the plurality of modulators, and an adjuster device iteratively adjusts the modulator bias for each of the plurality of modulators for which the current modulator bias is determined to be sub-optimal until a threshold condition has been met.

Abstract: Systems and methods for optical communication are disclosed that include communicating data using one or more transceiver pairs coupled to a spatial-multiplexer (S-MUX); performing bi-directional transmissions over an elliptical core optical fiber to a spatial-demultiplexer (S-DEMUX) using spatial modes to communicate data in either direction between two transceiver pairs with low crosstalk and without optical circulators or wavelength-division multiplexing (WDM); and communicating data from the S-DEMUX with g one or more transceiver pairs.

Abstract: A system for optimizing signal quality in an optical communication system is provided including a transmitter for converting digital signals to optical signals, the transmitter including a transmitter digital signal processing chip including a pre-distortion logic and a transmitter look-up table (LUT). A receiver is operatively coupled to the transmitter for receiving and converting the optical signals from the transmitter to digital signals. The receiver includes a receiver digital signal processing chip including a correction logic and a receiver look-up table (LUT). The transmitter LUT is constructed by scaling the receiver LUT by a weight factor and is iteratively updated based on a weighted sum of the receiver LUT.

Abstract: A method of wavelength conversion without polarization tracking is provided. A system is also provided that converts an input signal into an output signal of a different wavelength that contains all of the amplitude, phase, and polarization information of the original signal. The method includes separating, using a polarization-diversity optical mixer, an input optical signal of a first wavelength into a plurality of electrical signals containing amplitudes and phases while maintaining the polarization information of the input signal, converting each of the amplitudes and phases into individual photo-currents using a photo-diode, converting each of the output photo-currents into voltages using an amplifier, modulating the multitude of voltages to a second wavelength using a modulator, where the separated electrical signals are up-converted to generate an output optical signal that maintains the same amplitude, phase, and polarization information as was contained in the input signal.

Abstract: Aspects of the present disclosure describe methods and systems for improved secure key generation and distribution employing environmental instability induced signal phase fluctuations that are compatible with commercial wavelength division multiplexed (WDM) optical systems and associated optical amplifiers for long-haul transmission.

Abstract: The present invention is directed to a controller for generating ultra-wide band electrical signals for high data-rate single optical carrier transmission. The controller includes generating a digitally jointed baseband signal with radio frequency RF up-conversion to create optical dual side bands.

Abstract: The present method is for generating a 4-level optical signal and it includes providing a continuous wave CW optical source; modulating the CW optical source with a first intensity modulator driven by a binary electrical signal a n Gbits/s to generate an optical signal; employing a second intensity modulator as a pulse carving modulator that is driven by an RF signal at n GHz thereby generating a 4 level optical signal for subsequent detection by a receiver.

Abstract: Aspects of the present disclosure are directed to the mitigation of multi-path interference from quasi-single-mode fiber using hybrid span configuration and digital signal processing wherein a hybrid span of quasi-single mode fibers and single-mode fibers are used to configure the hybrid span. Additional aspects are directed to introducing a low-baud rate sub-banding signal to reduce the number of DD-LMS taps required when compensating the multi-path interference as the low-baud rate signal requires fewer taps to cover a given range of MPI as compared to a high-baud rate signal. Finally further aspects are directed to an ALMS equalizer which further reduces the number of equalizer taps by shifting its center tap towards the right if higher-order modes transmit slower than a fundamental mode, otherwise the center tap is shifted to the left.

Abstract: Systems and methods are disclosed for data communication by performing RF sub-band multiplexing and demultiplexing by cascading a radio-frequency (RF) mixing module and optical dual-polarized (DP) QPSK modulator forhybrid RF/optical IQ modulation; and performing intra-transceiver optical superchannel switching through the RF sub-band multiplexing.

Abstract: An optical communication method includes converting an optical pulse amplitude modulation (PAM) signal to a square QAM signal using an optical delay interferometer (DI) to perform all-optical PAM to QAM conversion in the DI; performing optical de-correlation of I and Q tributaries of the QAM signal to avoid frequency dependent attenuation in RF cabling which impacts signal quality; and finding optimal phase control mechanism of the DI by monitoring and equalizing down-converted I and Q electrical signal amplitudes, using coherent detection; and emulating a square quadrature amplitude modulation (QAM) optical signal with duplicated data copies.