Abstract: Aspects of the present disclosure describe systems, methods and structures providing bidirectional optical fiber communication and sensing using the same fiber transmission band and bidirectional WDM fiber sharing such that communications channels and optical fiber sensing channel(s) coexist on the same fiber. As a result, nonlinear interaction between communications channels and interrogating pulse(s) of sensing are much reduced or eliminated.

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: Aspects of the present disclosure describe optical fiber sensing systems, methods and structures and application employing coherent detection of backscattered signals.

Abstract: Aspects of the present disclosure describe systems, methods and structures and applications of optical fiber sensing. Of significance, systems, methods, and structures according to aspects of the present disclosure may reuse and/or retrofit/upgrade existing optical fiber cables as part of optical fiber sensing that may find important societal application including intrusion detection, road traffic monitoring and infrastructure health monitoring. Combining such optical fiber sensing with artificial intelligence (AI) further enables powerful applications at low(er) cost.

Abstract: Aspects of the present disclosure describe systems, methods and structures in which a hybrid neural network combining a CNN and several ANNs are shown useful for predicting G-ONSR for Ps-256QAM raw data in deployed SSMF metro networks with 0.27 dB RMSE. As demonstrated, the CNN classifier is trained with 80.96% testing accuracy to identify channel shaping factor. Several ANN regression models are trained to estimate G-OSNR with 0.2 dB for channels with various constellation shaping.

Abstract: Aspects of the present disclosure describe systems, methods and structures providing bidirectional optical fiber communication and sensing using the same fiber transmission band and bidirectional WDM fiber sharing such that communications channels and optical fiber sensing channel(s) coexist on the same fiber. As a result, nonlinear interaction between communications channels and interrogating pulse(s) of sensing are much reduced or eliminated.

Abstract: Aspects of the present disclosure describe systems, methods, and structures for passive optical add/drop multiplexing (POADM) architectures that remove the prior art requirement of an optical amplifier (i.e., repeater-less) at the POADM nodes.

Abstract: Aspects of the present disclosure describe systems, methods, and structures for high speed frequency hopping distributed acoustic sensing using an acousto-optic modulated (AOM), gated re-circulating loop and a frequency shifted receiver local oscillator. Using the re-circulating loop controlled by the AOM to generate frequency-hopping pulse(s) increases DAS acoustic bandwidth overcomes infirmities exhibited in the art that generate multiple frequency patterns that are not suitable for long-distance DAS. Additionally, by employing frequency shifted local oscillator (LO) with asymmetric in band detection, bandwidth requirements are reduced by one half.

Abstract: A system to perform distributed acoustic sensing (DAS) in an environment with acoustic vibrations present includes at least an optical fiber positioned in said environment, wherein the optical fiber comprises N spatial channels and N laser pulses are launched into the N spatial channels of the optical fiber and propagate over a fiber length; and one or more sensors to measure N signals of acoustic vibration amplitude and frequency from each of N spatial channels, wherein the N signals are digitally added for spatial averaging and applied to determine DAS.

Abstract: Systems and methods for predicting performance of a modulation system are provided. A neural network model is trained using performance information of a source system. The neural network model is modified with transferable knowledge about a target system to be evaluated. The neural network model is tuned using specific characteristics of the target system to create a source-based target model. The target system performance is evaluated using the source-based target model to predict system performance of the target system.

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: Aspects of the present disclosure describe systems, methods, and structures for passive optical add/drop multiplexing (POADM) architectures that remove the prior art requirement of an optical amplifier (i.e., repeater-less) at the POADM nodes.

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: 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: Methods and system for transmitting data includes converting multiple optical beams to distinct respective spatial modes. Data is modulated onto each of the optical beams. The optical beams are combined into a single transmission beam. The transmission beam is launched onto a multimode optical fiber having an elliptical core.

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 method and system for remote sensing using optical orbital angular momentum (OAM)-based spectroscopy for lateral motion detection. The method includes applying an OAM mode on a light beam to generate an OAM light beam, the OAM light beam having an optical OAM spectrum, applying an OAM optical beam tilt on the OAM light beam to generate a tilted OAM light beam, transmitting the tilted OAM light beam on a remote object, such that the remote object interacts with the tilted OAM light beam, receiving a reflected OAM spectrum associated with the remote object, the reflected OAM spectrum having power values of OAM modes on opposite sides of an OAM launch mode, and displaying lateral motion of the remote object based on the reflected OAM spectrum by comparing the power values.

Abstract: A system to perform distributed acoustic sensing (DAS) in an environment with acoustic vibrations present includes at least an optical fiber positioned in said environment, wherein the optical fiber comprises N spatial channels and N laser pulses are launched into the N spatial channels of the optical fiber and propagate over a fiber length; and one or more sensors to measure N signals of acoustic vibration amplitude and frequency from each of N spatial channels, wherein the N signals are digitally added for spatial averaging and applied to determine DAS.

Abstract: Methods and system for transmitting data includes converting multiple optical beams to distinct respective spatial modes. Data is modulated onto each of the optical beams. The optical beams are combined into a single transmission beam. The transmission beam is launched onto a multimode optical fiber having an elliptical core.