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US 11,698,445 B2Granted
Automotive Lidar with multi-spectral depth imaging and discrete scanning mechanism
AssigneeGM Global Technology Operations LLC
InventorTzvi Philipp
Life of this patent
Estimating the term…
Abstract
A vehicle, Lidar system for the vehicle and method of scanning an object with the Lidar system. The Lidar system includes a first quarter wave plate, a first deflection stage and a detector. The first quarter wave plate produces a circularly polarized scanning beam of light. The first deflection stage selects a rotation direction for a polarization vector of the scanning beam and deflects the scanning beam by a selected angle based on the selected rotation direction of the polarization vector. The detector receives a reflected beam that is a reflection of the scanning beam from the object.
Claims17
A method of scanning an object with a Lidar system, comprising:
- receiving a scanning beam having an s-polarization at a Faraday rotator that rotates the scanning beam to a polarization direction at 45 degrees to the s-polarization;
- receiving the scanning beam at a scanning mechanism, the scanning mechanism comprising:
- a first quarter wave plate configured to receive the scanning beam having the polarization direction at 45 degrees from the Faraday rotator and impart a circular polarization to the scanning beam;
- a first deflection stage that deflects the scanning beam by a selected angle based on a rotation direction of the circular polarization;
- a second quarter wave plate configured to receive the scanning beam from the first deflection stage and impart a linear polarization on the scanning beam;
- reflecting the scanning beam off the object to form a reflected beam, wherein the reflected beam retraces a path of the scanning beam through the second quarter wave plate, the first deflection stage and the first quarter wave plate to enter the Faraday rotator with a polarization direction of 45 degrees to the s-polarization direction,
- rotating the reflected beam by 45 degrees at the Faraday rotator to form linear polarized light having a p-polarization;
- and
- detecting the object using the reflected beam of light having the p-polarization.
6 more elements
A Lidar system for a vehicle, comprising:
- a Faraday rotator configured to receive a scanning beam that is linearly polarized along an s-polarization direction and rotate the scanning beam from the s-polarization direction to a polarization direction at 45 degrees to the s-polarization direction;
- a scanning mechanism having a longitudinal axis, comprising:
- a first quarter wave plate configured to receive the scanning beam having the polarization direction at 45 degrees and impart a circular polarization to the scanning beam;
- a first deflection stage configured to deflect the scanning beam from the longitudinal axis based on a rotation direction of the circular polarization;
- and
- a second quarter wave plate configured to receive the scanning beam from the first deflection stage and impart a linear polarization on the scanning beam,
- wherein the scanning beam reflects off an object to form a reflected beam that retraces a path of the scanning beam through the second quarter wave plate, the first deflection stage and the first quarter wave plate to enter the Faraday rotator with a polarization direction of 45 degrees to the s-polarization direction,
- wherein the Faraday rotator rotates the reflected beam by 45 degrees to form linear polarized light having a p-polarization;
- and
- a detector for detecting the object using the reflected beam having the p-polarization.
7 more elements
A vehicle, comprising:
- a Lidar system including:
- a Faraday rotator configured to receive a scanning beam that is linearly polarized along an s-polarization direction and rotate the scanning beam to a polarization direction at 45 degrees to the s-polarization direction;
- and
- a scanning mechanism having a longitudinal axis, the scanning mechanism:
- a first quarter wave plate configured to receive the scanning beam having the polarization direction at 45 degrees and impart a circular polarization to the scanning beam;
- a first deflection stage that deflects the scanning beam based on a rotation direction of the circular polarization;
- and
- a second quarter wave plate configured to receive the scanning beam from the first deflection stage and impart a linear polarization on the scanning beam,
- wherein the scanning beam reflects off an object to form a reflected beam that retraces a path of the scanning beam through the second quarter wave plate, the first deflection stage and the first quarter wave plate to enter the Faraday rotator with a polarization direction of 45 degrees to the s-polarization direction,
- wherein the Faraday rotator rotates the reflected beam by 45 degrees to form linear polarized light having a p-polarization;
- and
- a detector for detecting the object using the reflected beam of light having the p-polarization.
9 more elements
Dependencies are inferred from the claim text.