Stray light reduction in sensors

1 . A method comprising:

emitting a first signal via a transmit path of a depth sensor;

receiving a second signal via a receive path of the depth sensor, the second signal based at least in part on the first signal;

activating a first polarization associated with the transmit path, based at least in part on the second signal, wherein activating the first polarization comprises rotating a first polarizer associated with the transmit path;

emitting a third signal via the transmit path, the third signal associated with the first polarization;

receiving a fourth signal via the receive path, the fourth signal associated with a second polarization and based at least in part on the third signal, wherein a first polarization angle associated with the first polarization and a second polarization angle associated with the second polarization are dynamically adjustable;

determining, based at least in part on the fourth signal, a distance associated with a pixel location; and

controlling a vehicle based on the distance.

2 . The method of claim 1 , wherein one or more of the first polarization angle or the second polarization angle is dynamically adjusted based on a predetermined progression.

3 . The method of claim 1 , wherein the first polarizer is associated with a vertical cavity surface emitting laser, a light emitting diode, or combination thereof.

4 . The method of claim 1 , further comprising:

determining, based at least in part on the fourth signal, a presence of a retroreflector in an environment; and

controlling the vehicle further based at least in part on the presence of the retroreflector.

5 . The method of claim 1 , further comprising:

determining that at least a portion of the fourth signal is indicative of a likelihood of a retroreflector in an environment;

determining that the likelihood of the retroreflector in the environment meets or exceeds a threshold; and

applying a polarization filter to the transmit path or the receive path based on determining that the likelihood of the retroreflector in the environment meets or exceeds the threshold.

6 . The method of claim 1 , further comprising:

emitting a fifth signal via the transmit path, the fifth signal associated with the first polarization;

receiving a sixth signal via the receive path, the sixth signal associated with a third polarization and based at least in part on the fifth signal;

determining, based at least in part on the third signal and the sixth signal, an intensity difference associated with the pixel location; and

determining, based at least in part on the intensity difference, an object associated with the pixel location.

7 . The method of claim 1 , wherein the depth sensor is one of a time of flight sensor or Light Detection and Ranging (LIDAR) sensor.

8 . The method of claim 1 , wherein controlling the vehicle based on the distance comprises activating a vehicle operation mode.

9 . The method of claim 1 , further comprising:

receiving a fifth signal via a second receive path, the fifth signal associated with a third polarization and based at least in part on the third signal;

determining, based at least in part on the fourth signal and the fifth signal, an intensity difference associated with the pixel location; and

determining, based at least in part on the intensity difference, an object associated with the pixel location.

10 . The method of claim 1 , further comprising:

receiving a fifth signal via a second receive path of the depth sensor, the second signal based on the fifth signal, the fifth signal associated with a third polarization and based at least in part on the third signal;

determining, based at least in part on the fourth signal and the fifth signal, the distance associated with the pixel location; and

controlling the vehicle based on the distance.

11 . The method of claim 1 , further comprising:

receiving a fifth signal via the receive path, the fifth signal associated with a third polarization and based at least in part on the third signal; and

determining, based at least in part on the fourth signal and the fifth signal, a surface normal associated with a surface associated with the pixel location.

12 . A system comprising:

one or more processors; and

one or more non-transitory computer-readable media storing instructions executable by the one or more processors, wherein the instructions, when executed, cause the system to perform operations comprising:

emitting a first signal via a transmit path of a depth sensor;

receiving a second signal via a receive path, the second signal based at least in part on the first signal;

activating a first polarization associated with the transmit path, based at least in part on the second signal, wherein activating the first polarization comprises rotating a first polarizer associated with the transmit path;

emitting a third signal via the transmit path, the third signal associated with the first polarization;

receiving a fourth signal via the receive path, the fourth signal associated with a second polarization and based at least in part on the third signal, wherein a first polarization angle associated with the first polarization and a second polarization angle associated with the second polarization are dynamically adjustable;

determining, based at least in part on the fourth signal, a distance associated with a pixel location; and

controlling a vehicle based on the distance.

13 . The system of claim 12 , wherein the second polarization is associated with a second polarizer in the receive path.

14 . The system of claim 12 , wherein the first polarizer is associated with a vertical cavity surface emitting laser, a light emitting diode, or a combination thereof.

15 . The system of claim 12 , the operations further comprising:

determining, based at least in part on the fourth signal, a presence of a retroreflector in an environment; and

controlling the vehicle based at least in part on the presence of the retroreflector.

16 . The system of claim 12 , wherein the depth sensor is one of a time of flight sensor or a Light Detection and Ranging (LIDAR) sensor.

17 . One or more non-transitory computer-readable media storing instructions that, when executed by one or more processors, cause the one or more processors to perform operations comprising:

emitting a first signal via a transmit path of a depth sensor;

receiving a second signal via a receive path, the second signal based at least in part on the first signal;

activating a first polarization associated with the transmit path, based at least in part on the second signal, wherein activating the first polarization comprises rotating a first polarizer associated with the transmit path;

emitting a third signal via the transmit path, the third signal associated with the first polarization;

receiving a fourth signal via the receive path, the fourth signal associated with a second polarization and based at least in part on the third signal, wherein a first polarization angle associated with the first polarization and a second polarization angle associated with the second polarization are dynamically adjustable;

determining, based at least in part on the fourth signal, a distance associated with a pixel location; and

controlling a vehicle based on the distance.

18 . The one or more non-transitory computer-readable media of claim 17 , wherein the second polarization is associated with a second polarizer in the receive path.

19 . The one or more non-transitory computer-readable media of claim 17 , wherein the first polarizer is associated with a vertical cavity surface emitting laser, a light emitting diode, or a combination thereof.

20 . The one or more non-transitory computer-readable media of claim 17 , the operations further comprising:

determining, based at least in part on the fourth signal, a presence of a retroreflector in an environment; and

controlling the vehicle based at least in part on the presence of the retroreflector.