Abstract: Methods and apparatus for characterizing optical fiber links by optical time-domain reflectometry are disclosed. To resolve compromises between the signal-to-noise ratio, duration, and resolution of optical-time domain reflectometry measurements, embodiments of the present disclosure use coded sequences of return-to-zero light pulses. Each return-to-zero light pulse in a coded sequence includes a guard interval to mitigate the effects of pulse shape distortions. In some embodiments, the sequences of return-to-zero light pulses encode complementary Golay correlation codes. Some embodiments provide methods for encoding and decoding the sequences of return-to-zero pulse sequences. Some embodiments provide an optical time-domain reflectometry apparatus including a light source unit, optical coupler, light sensor, and processing device.

Abstract: A method for monitoring impairment includes: receiving a first received waveform sent by the coherent receiver; obtaining a second received waveform including a first sub-waveform and a second sub-waveform with a relative first delay therebetween according to the first received waveform; obtaining a template at a predetermined location on the fiber link according to the second received waveform, wherein the template is used for representing a nonlinear noise by a first sub-signal waveform and a second sub-signal waveform at the predetermined location that are respectively obtained from the first sub-waveform and the second sub-waveform and have the first delay therebetween; obtaining a correlation between the second received waveform and the template; changing a value of the first delay to obtain values of the correlation corresponding to different values of the first delay; and outputting a value of the first delay corresponding to a maximum value of the correlation as impairment estimation.

Abstract: Aspects of the disclosure provide a method of a LiDAR system to determine the distance of an object from the LiDAR system. Embodiments of the LiDAR system can use a coarse estimate of the distance of an object from the LiDAR system which is then used by a fast search to determine an estimate of the distance of an object from the LiDAR system within a precision threshold. In some embodiments the LiDAR system can use adaptive precision when determining the distance of an object from the LiDAR system.

Abstract: The disclosed systems and methods are for monitoring optical performance in a spatial division multiplexing (SDM) system, comprising: i) extracting, by an optical coupler, at least a portion of a plurality optical signals propagating in different communication lanes of the SDM-based optical communication system, wherein each optical signal of the plurality of optical signals is modulated with a distinguishable pilot tone (PT) signal; ii) combining, by the optical coupler, the extracted portion of the plurality of optical signals, and generate a combined optical signal; iii) extracting, by a pilot tone detector (PTD), PT signals from the combined optical signal; iv) determining, by the PTD, optical signal specific information included in the PT signals; and v) computing, by the PTD, optical power of each optical signal based on the optical signal specific information.

Abstract: A method for monitoring generalized optical signal-to-noise ratio (gOSNR) is provided, which is applied to monitoring of an optical signal received by a coherent receiver through a fiber link. The method includes: obtaining a first received waveform; obtaining a signal part of the first received waveform; obtaining a noise part of the first received waveform according to the signal part and the first received waveform; obtaining a first correlation between the noise part and a first template at a predetermined location on the fiber link, the first correlation indicating a signal power at the predetermined location; obtaining a second correlation between the noise part and a second template at the predetermined location on the fiber link, the second correlation indicating a signal power and noise power at the predetermined location; and obtaining gOSNR at the predetermined location according to the first correlation and the second correlation.

Abstract: The disclosed systems, and methods for detecting an improper protection in an optical communication network comprising: i) receiving, by a first Coherent-Optical Time Domain Reflectometer (C-OTDR), a first reflected optical signal from a first optical fiber; ii) receiving, by a second C-OTDR, a second reflected optical signal from a second optical fiber; iii) pre-processing, by a processor, the first reflected optical signal and the second reflected optical signal; iv) determining, by the processor, a category of the first C-OTDR and the second C-OTDR; v) depending upon the category of the first C-OTDR and the second C-OTDR, computing a correlation between the first preprocessed reflected optical signal and the second preprocessed reflected optical signal based on a first correlation computation technique or a second correlation computation technique; and vi) based on the computed correlation, detecting the improper protection in the optical communication network.

Abstract: A spatial light modulation (SLM) device is disclosed. The SLM device includes an electronic backplane and a pixel array structure including a plurality of pixels. Each pixel includes a reflective layer disposed atop the electronic backplane, a phase change material (PCM) layer disposed atop the reflective layer, a phase of the PCM layer being selectively in a crystalline state or an amorphous state based on a temperature thereof and an encapsulation layer disposed atop the PCM layer such that the PCM layer is sandwiched between the reflective layer and the encapsulation layer. The electronic backplane is operatively connected to a controller and generates electrical current for defining an independent heat profile in the PCM layer of each pixel through Joule's effect, a variation of the phase of the PCM layer being used to modulate optical properties of an incoming optical signal reaching the spatial light modulation device.

Abstract: A method and system for inspecting polarization in a fibered optical path. The method being executed by a computer-implemented system comprising a controller and at least one detector communicatively coupled to the controller, the computer-implemented system being operatively connected to the fibered optical path, including: causing a laser to emit at least one optical pulse into the fibered optical path; detecting a plurality of reflected optical signals from the fibered optical path; determining a plurality of experimental correlation values based on the plurality of reflected optical signals and a reference signal function; and in response to a given experimental correlation value of the plurality of experimental correlation values being less than a threshold, identifying a mechanical disturbance caused by birefringence in the fibered optical path, the mechanical disturbance being located at a location of the plurality of locations corresponding to the given experimental correlation value.

Abstract: A configurable optical amplifier platform for forming a configurable optical amplifier and including an input module that receives one or more optical signals and a mounting structure operatively connected to the input module is disclosed. The mounting structure has defined therein a plurality of component compartments arranged in a plurality of series that receive a same type of free-space optical components in compartments of a given series. A first series receives optical isolators, a second series receives optical filters and a third series receives optical attenuators. The configurable optical amplifier platform also includes an active module operatively connected to the mounting structure and receiving signal outputs from the mounting structure and providing optical amplification thereto.

Abstract: The disclosed systems, structures, and methods are directed to risk assessment of an optical network. A simulation framework includes a risk map engine including a performance prediction engine that generates a simulation of the optical network based at least in part on an input network topology and/or service map. The prediction performance engine runs the simulation to predict, based at least in part on received network telemetry data, direct and indirect impacts on the optical network of a risk factor represented in a what-if scenario. The risk map engine includes a risk assessment engine that determines a risk associated with the risk factor based at least in part on the predicted direct and indirect impacts and on a likelihood of occurrence of the risk factor. The risk assessment engine generates a risk map showing aggregate risks to the optical network from a plurality of risk factors.

Abstract: The disclosed LiDAR systems and methods are for object detection. The LiDAR system for object detection comprising: i) a receiver configured to receive a light signal reflected from an object; ii) a digital converter configured to convert the received light signal into a digital signal; iii) a pre-processor configured to pre-process the digital signal based on median filtering and to generate a pre-processed signal corresponding to the digital signal; and iv) a processor configured to analyze the pre-processed signal based on a threshold technique to detect a presence of the object.

Abstract: The disclosed systems and methods for determining spectrum-resolved signal-to-noise ratio (SNR) in an online dense wavelength division multiplexing (DWDM) optical link, the method comprising: i) receiving a noise affected optical signal; ii) converting the received optical signal into a digital signal; iii) processing the digital signal to extract the noise affected transmitted signal; iv) decoding the noise-affected transmitted signal and reconstructing an original transmitted signal; v) converting the noise-affected transmitted signal into frequency domain noise-affected transmitted signal; vi) converting the original transmitted signal into frequency domain original transmitted signal; vii) selecting spectrum slices from the frequency domain noise-affected transmitted signal and the frequency domain original transmitted signal; viii) converting the spectrum slices into time domain portions of the noise-affected transmitted signal and the original transmitted signal respectively; ix) correlating the time do

Abstract: An optical fiber configured to improve the pump conversion efficiency of an L-band fiber amplifier which uses the multimode pump source. By directly absorbing multimode light including 915 nm, an active fiber core region co-doped with both erbium and ytterbium can provide gain to the L-band signals via stimulated emission. The unwanted C-band amplified spontaneous emission (ASE) light generate from this active fiber core region can be absorbed by another active fiber core region doped with erbium, then provides additional gain to the L-band signals. Active regions and cladding can be configured to match a given spatial mode of the optical signal. Signal-pump combiners with end-coupling or side coupling can be used.

Abstract: The disclosed systems, and methods for detecting an improper protection in an optical communication network comprising: i) receiving, by a first Coherent-Optical Time Domain Reflectometer (C-OTDR), a first reflected optical signal from a first optical fiber; ii) receiving, by a second C-OTDR, a second reflected optical signal from a second optical fiber; iii) pre-processing, by a processor, the first reflected optical signal and the second reflected optical signal; iv) determining, by the processor, a category of the first C-OTDR and the second C-OTDR; v) depending upon the category of the first C-OTDR and the second C-OTDR, computing a correlation between the first preprocessed reflected optical signal and the second preprocessed reflected optical signal based on a first correlation computation technique or a second correlation computation technique; and vi) based on the computed correlation, detecting the improper protection in the optical communication network.

Abstract: System and method for improving performance in an optical link. The optical link includes a plurality of communication channels for transmitting an optical signal. The method is performed by a link controller of the optical link. The method comprises determining a noise level of at least one channel of the plurality of channels, determining a launch power offset for the at least one channel and performing link commissioning based at least in part on the launch power offset.

Abstract: The disclosed systems and methods for detecting a location of reflection in an optical link comprising: i) receiving an optical signal; ii) receiving a plurality of first type of delayed optical signals corresponding to the optical signal; iii) determining a first type of time delays associated with each of the plurality of first type of delayed optical signals; iv) receiving a plurality of second type of delayed optical signals corresponding to the optical signal; v) determining a second type of time delays associated with the each of the plurality of second type of delayed optical signals; vi) computing relative delays from the second type of time delays; vii) comparing the relative delays with the first type of time delays; and viii) determining a location of a given optical element contributing to the reflections based on the given relative delay and the location of the AR.

Abstract: The disclosed systems, structures, and methods are directed to risk assessment of an optical network. A simulation framework includes a risk map engine including a performance prediction engine that generates a simulation of the optical network based at least in part on an input network topology and/or service map. The prediction performance engine runs the simulation to predict, based at least in part on received network telemetry data, direct and indirect impacts on the optical network of a risk factor represented in a what-if scenario. The risk map engine includes a risk assessment engine that determines a risk associated with the risk factor based at least in part on the predicted direct and indirect impacts and on a likelihood of occurrence of the risk factor. The risk assessment engine generates a risk map showing aggregate risks to the optical network from a plurality of risk factors.

Abstract: The disclosed systems and methods are for monitoring optical performance in a spatial division multiplexing (SDM) system, comprising: i) extracting, by an optical coupler, at least a portion of a plurality optical signals propagating in different communication lanes of the SDM-based optical communication system, wherein each optical signal of the plurality of optical signals is modulated with a distinguishable pilot tone (PT) signal; ii) combining, by the optical coupler, the extracted portion of the plurality of optical signals, and generate a combined optical signal; iii) extracting, by a pilot tone detector (PTD), PT signals from the combined optical signal; iv) determining, by the PTD, optical signal specific information included in the PT signals; and v) computing, by the PTD, optical power of each optical signal based on the optical signal specific information.

Abstract: The disclosed systems and methods are for reducing polarization dependent loss in an optical link including: i) changing, by a state of polarization (SOP) controller, an SOP of an optical signal propagating in the optical link; ii) computing, by a link controller, a polarization dependent loss (PDL) in a portion of the optical link; iii) generating, by the link controller, a control signal according to the PDL; and iv) based on the control signal, changing, by the SOP controller, the SOP of the optical signal.

Abstract: The disclosed systems and methods for detecting a location of reflection in an optical link comprising: i) receiving an optical signal; ii) receiving a plurality of first type of delayed optical signals corresponding to the optical signal; iii) determining a first type of time delays associated with each of the plurality of first type of delayed optical signals; iv) receiving a plurality of second type of delayed optical signals corresponding to the optical signal; v) determining a second type of time delays associated with the each of the plurality of second type of delayed optical signals; vi) computing relative delays from the second type of time delays; vii) comparing the relative delays with the first type of time delays; and viii) determining a location of a given optical element contributing to the reflections based on the given relative delay and the location of the AR.