Apparatus and method for cancellation of scattered light in lidar sensors

A lidar device comprising:

• at least one far-field transmitter configured to emit optical signals as tightly focused beams, the at least one far-field transmitter being structured and arranged to scan a field of view (FOV) of the lidar system with the tightly focused beams;
• a near-field transmitter structured and arranged to emit a diffuse flash beam optical signal separately and distinctly from the tightly focused beams emitted by the at least one far-field transmitter;
• and
• a receiver configured to receive return signals based on the optical signals emitted by both the far-field and the near-field transmitters, the receiver comprising:
• a first photodetector configured to (i) receive a dazzle signal arising from internal reflections and a valid return signal reflected from an object in the environment, and (ii) generate a first electrical current in response to the dazzle signal and the valid return signal;
• a second photodetector configured to (i) receive the dazzle signal but not the valid return signal and (ii) generate a second electrical current in response to the dazzle signal;
• and
• an amplifier configured to receive a third electrical current equal to a difference between the first electrical current and the second electrical current,
• wherein the lidar device is configured to detect objects positioned from about 0.1 meters to about 0.6 meters from the device in response to the return signals generated by the near-field transmitter.