Disclosed herein are systems and methods for linearizing frequency chirp in a frequency-modulated continuous wave (FMCW) coherent LiDAR system. Exemplary methods can include generating a continuous wave laser signal having a frequency characteristic, in which the frequency characteristic can include a frequency chirp over a frequency band in at least one period; and receiving a signal based on the generated laser signal. The methods can further include mixing the received signal with a local oscillator signal, the local oscillator signal having the frequency characteristic; determining at least one beat frequency based on the mixed signal; sampling the mixed signal at a rate equal to at least two times the beat frequency; determining a correction signal based on the sampled signal; and applying the correction signal to the laser signal.

A frequency modulated, continuous wave (FMCW) laser using a microchip gain medium, an optical coupling element, and a tuning element is described. The laser may be part of a coherent laser ranging system.

At least one beam of an optical wave is transmitted along a transmission angle toward a target location from a send aperture of a transmitter. The optical wave comprises at least a first portion, and a second portion having a different characteristic from a characteristic of the first portion. Two or more receivers include at least one receiver comprising: a receive aperture arranged in proximity to at least one of the send aperture or a receive aperture of a different receiver, an optical phased array within the receive aperture, the optical phased array being configured to receive at least a portion of a collected optical wave arriving at the receive aperture along a respective collection angle, and a filter configured to filter the received portion of the collected optical wave according to the characteristic of the first portion of the optical wave.

At least one beam of an optical wave is transmitted along a transmission angle toward a target location from a send aperture of a transmitter. The optical wave comprises at least a first portion, and a second portion having a different characteristic from a characteristic of the first portion. Two or more receivers include at least one receiver comprising: a receive aperture arranged in proximity to at least one of the send aperture or a receive aperture of a different receiver, an optical phased array within the receive aperture, the optical phased array being configured to receive at least a portion of a collected optical wave arriving at the receive aperture along a respective collection angle, and a filter configured to filter the received portion of the collected optical wave according to the characteristic of the first portion of the optical wave.

Free-space optics for use in a light detection and ranging (LIDAR) apparatus include a polarization beam-splitter (PBS) to direct an optical beam in a first direction toward a target environment and to propagate a portion of the optical beam in a second direction for receipt by a photodetector (PD), a polarization wave plate (PWP) to convert the optical beam from a first polarization to a second polarization, and to convert the target return signal from a third polarization to a fourth polarization, and a lens system coupled between the PBS and the PWP to magnify the optical beam. The propagated portion of the optical beam comprises a local oscillator (LO) signal to mix with a target return signal to generate target information.

A laser system includes a resonant laser cavity configured to output a laser signal. The system also includes a utility waveguide configured to receive the laser signal from the laser cavity. The utility waveguide includes a perturbation region that is external to the laser cavity and receives the laser signal from the laser cavity and outputs a laser beam. The perturbation region includes one or more perturbation structures that each causes one or more perturbation(s) in the index of refraction of the utility waveguide. The perturbation structures are selected to provide optical feedback to the resonant laser cavity such that a power versus wavelength distribution in the laser beam is different from the power versus wavelength distribution that would be in the laser signal in the absence of the perturbation structures.

A photonic circulator deployed on a chip-scale light-detection and ranging (LiDAR) device includes a first arm that includes a first waveguide that is bonded onto a first member at a first bonding region, and a second arm that includes a second waveguide that is bonded onto a second member at a second bonding region. A first thermo-optic phase shifter is arranged on the first member and collocated with the first waveguide, and a second thermo-optic phase shifter is arranged on the second member and collocated with the second waveguide. The magneto-optic material and the first thermo-optic phase shifter of the first member cause a first phase shift in a first light beam travelling through the first waveguide, and the magneto-optic material and the second thermo-optic phase shifter of the second member cause a second phase shift in a second light beam travelling through the second waveguide.

A photonic circulator deployed on a chip-scale light-detection and ranging (LiDAR) device includes a first arm that includes a first waveguide that is bonded onto a first member at a first bonding region, and a second arm that includes a second waveguide that is bonded onto a second member at a second bonding region. A first thermo-optic phase shifter is arranged on the first member and collocated with the first waveguide, and a second thermo-optic phase shifter is arranged on the second member and collocated with the second waveguide. The magneto-optic material and the first thermo-optic phase shifter of the first member cause a first phase shift in a first light beam travelling through the first waveguide, and the magneto-optic material and the second thermo-optic phase shifter of the second member cause a second phase shift in a second light beam travelling through the second waveguide.

A light detection and ranging (LIDAR) system has a modulator to modulate a light signal from an optical source with a low-power mode at a section of a sweep signal to generate a pulsed light signal transmitted towards a target. The LIDAR system has a photodetector to receive a return beam from the target with an amplitude modulated (AM) signal portion and a frequency modulated (FM) signal portion. The LIDAR system processes the return beam with in-phase/quadrature (I/Q) detection to extract the AM signal portion and the FM signal portion. The system determines a range value and a velocity value for the target based on the extracted AM signal portion and the extracted FM signal portion.

A light detection and ranging (LIDAR) system has a modulator to modulate a light signal from an optical source with a low-power mode at a section of a sweep signal to generate a pulsed light signal transmitted towards a target. The LIDAR system has a photodetector to receive a return beam from the target with an amplitude modulated (AM) signal portion and a frequency modulated (FM) signal portion. The LIDAR system processes the return beam with in-phase/quadrature (I/Q) detection to extract the AM signal portion and the FM signal portion. The system determines a range value and a velocity value for the target based on the extracted AM signal portion and the extracted FM signal portion.