Abstract: Systems and methods for detecting blockages for light detection and ranging (“LiDAR”) devices are disclosed. According to one embodiment, a light detection and ranging (LiDAR) blockage detection method includes emitting, by an active channel of a plurality of channels of a LiDAR device, an optical signal toward a configured position on a housing of the LiDAR device. A passive listening channel of the plurality of channels receives a return signal originating from the optical signal. Based on a comparison of data derived from the return signal and data derive from a reference signal, a determination is made as to whether a blockage is present at the configured position on the housing.

Abstract: LiDAR-based immersive 3D reality capture systems and methods are disclosed. The reality capture system includes a set of LiDAR sensors disposed around an environment and configured to capture one or more events occurring within the environment. The reality capture system also includes a corresponding set of cameras disposed around the environment. Each camera is mounted on a same gimbal with a corresponding LiDAR sensor and has a same optical axis as the corresponding LiDAR sensor. The reality capture system further includes a base station viewpoint generator coupled to the set of LiDAR sensors and the cameras to generate a video feed based on data received from the LiDAR sensors and the cameras. The reality capture system additionally includes a virtual reality device coupled to the base station viewpoint generator to receive and display the video feed generated by the base station viewpoint generator.

Abstract: A coherent optical receiver measures a portion of a spectra of a multi-channel optical signal that includes at least one signal adjacent to a selected signal. The coherent optical receiver determines structure and bandwidth information for the measured portion of spectra, and determines one or more filter parameters for the selected signal based on the structure and bandwidth information of the at least one signal adjacent to the selected signal. The coherent optical receiver adjusts one or more active filter parameters of a carrier phase estimator in the optical coherent receiver to have values corresponding to the determined one or more filter parameters.

Abstract: Feed-forward and feedback strategies are used to control local oscillator power and transimpedance amplifier gain in a high-speed coherent optical receiver.

Abstract: I/Q data skew in a QPSK modulator may be detected by sending identical or complementary data streams to I and Q channel PSK modulators, setting the relative carrier phase between I and Q to zero or ?, and monitoring the average QPSK output power, where the data streams sent to the I and Q channels include streams of alternating ones and zeroes.

Abstract: Digital timing error detection systems and techniques are described. The described techniques are independent of polarization and differential-group-delay and are used to perform timing recovery of polarization-multiplexed coherent optical systems.

Abstract: A method for determining, by a modulator assembly, an optimal drive point for a Mach-Zehnder modulator (MZM). The modulator assembly applies an electrical modulation signal to the MZM to modulate an optical input signal and create a modulated optical output signal, the modulated optical output having a spectrum that includes a first and third harmonic. The modulator assembly measures the difference in magnitude between the first harmonic and the third harmonic as the amplitude of the electrical modulation signal is varied, and determines a value for the amplitude of the electrical modulation signal that corresponds to a maximum difference between the first harmonic and the third harmonic.

Abstract: A coherent optical receiver measures a portion of a spectra of a multi-channel optical signal that includes at least one signal adjacent to a selected signal. The coherent optical receiver determines structure and bandwidth information for the measured portion of spectra, and determines one or more filter parameters for the selected signal based on the structure and bandwidth information of the at least one signal adjacent to the selected signal. The coherent optical receiver adjusts one or more active filter parameters of a carrier phase estimator in the optical coherent receiver to have values corresponding to the determined one or more filter parameters.

Abstract: A method for extracting admin information from a modulated optical signal. A coherent optical receiver receives the modulated optical signal, where a nominal carrier frequency of the modulated optical signal was modulated using a first slow frequency and second slow frequency associated with an electronic admin signal. The receiver converts the modulated optical signal to an electronic signal, and estimates estimating a plurality of carrier phases of the electronic signal. The receiver determines a plurality of offset values by calculating the time derivative of at least some of the estimated carrier phases, wherein each of the plurality of offset values are proportional to an associated frequency offset component, and the frequency of each offset value corresponds to the first slow frequency or the second slow frequency. The receiver extracts information corresponding to the electronic admin signal using the determined plurality of offset values.

Abstract: A method for detecting and measuring time skew in high-speed DP-QPSK coherent optical receivers is described.

Abstract: Patterns detected by a low-speed receiver at the output of a high-speed multiplexer are used to determine when multiplexer input lanes are deskewed.

Abstract: Coherent optical receiver performance is optimized and made adaptable to changing optical channel conditions by providing feedback loops to adjust receiver parameters based on measured receiver performance.

Abstract: I/Q data skew in a QPSK modulator may be detected by sending identical or complementary data streams to I and Q channel PSK modulators, setting the relative carrier phase between I and Q to zero or ?, and monitoring the average QPSK output power, where the data streams sent to the I and Q channels include pseudorandom streams of ones and zeroes.

Abstract: Feed-forward and feedback strategies are used to control local oscillator power and transimpedance amplifier gain in a high-speed coherent optical receiver.

Abstract: Digital timing error detection systems and techniques are described. The described techniques are independent of polarization and differential-group-delay and are used to perform timing recovery of polarization-multiplexed coherent optical systems.

Abstract: I/Q data skew in a QPSK modulator may be detected by sending identical or complementary data streams to I and Q channel PSK modulators, setting the relative carrier phase between I and Q to zero or ?, and monitoring the average QPSK output power, where the data streams sent to the I and Q channels include streams of alternating ones and zeroes.

Abstract: I/Q data skew in a QPSK modulator may be detected by sending identical or complementary data streams to I and Q channel PSK modulators, setting the relative carrier phase between I and Q to zero or ?, and monitoring the average QPSK output power, where the data streams sent to the I and Q channels include pseudorandom streams of ones and zeroes.

Abstract: Patterns detected by a low-speed receiver at the output of a high-speed multiplexer are used to determine when multiplexer input lanes are deskewed.

Abstract: A method for detecting and measuring time skew in high-speed DP-QPSK coherent optical receivers is described.