Chip-scale coherent lidar utilizing quantum dots

1. A LiDAR system comprising:

a laser source having a laser cavity and configured to output electromagnetic radiation; and

an optical amplifier including quantum dots and positioned outside the laser cavity to receive the electromagnetic radiation output from the laser source;

wherein the optical amplifier is configured to:

amplify the received electromagnetic radiation using the quantum dots; and

output the amplified electromagnetic radiation.

2. The LiDAR system of claim 1 , wherein:

the optical amplifier includes a pre-amplifier and a post-amplifier;

both the pre-amplifier and the post-amplifier include quantum dots;

the pre-amplifier receives the electromagnetic radiation output from the laser source, amplifies the received electromagnetic radiation, and outputs the amplified electromagnetic radiation to the post-amplifier;

the post-amplifier receives the amplified electromagnetic radiation output from the pre-amplifier, further amplifies the amplified electromagnetic radiation, and outputs the twice amplified electromagnetic radiation.

3. The LiDAR system of claim 2 , wherein the quantum dots of the pre-amplifier are made of a same material as the quantum dots of the post-amplifier, such that a shift in amplification properties of the pre-amplifier corresponds to a shift in amplification of the post-amplifier.

4. The LiDAR system of claim 2 , wherein the laser cavity, preamplifier, and post-amplifier are located on separate chips that are integrated together.

5. The LiDAR system of claim 1 , wherein the laser source includes a laser gain region and the laser gain includes quantum dots.

6. The LiDAR system of claim 2 , wherein the quantum dots of the pre-amplifier are made of a same material as both the quantum dots of the post-amplifier and the quantum dots of the laser gain region, such that a shift in amplification properties of the pre-amplifier corresponds to a shift in amplification properties of the post-amplifier and a shift in amplification properties of the laser gain region.

7. The LiDAR system of claim 1 , wherein the laser cavity and the optical amplifier are included on a same semiconductor chip, such that optical coupling losses are reduced between the laser source and the optic amplifier.

8. The LiDAR system of claim 7 , wherein the LiDAR system includes a single optical amplifier.

9. The LiDAR system of claim 7 , wherein the laser cavity and the optical amplifier are separated by a photonic integrated circuit structure.

10. The LiDAR system of claim 2 , wherein the pre-amplifier and the post-amplifier are separated by a photonic integrated circuit structure.

11. The LiDAR system of claim 1 , wherein:

the laser source comprises a semiconductor laser;

the optical amplifier has a gallium arsenide (GaAs) substrate; and

the quantum dots are made from indium arsenide (InAs) and have a wavelength output included in a range of 1180-1400 nm.

12. The LiDAR system of claim 1 , wherein the quantum dots are made from indium phosphide (InP) and have a wavelength output included in a range of 1260-1700 nm.

13. The LiDAR system of claim 1 , wherein the laser source is tunable to alter a wavelength of the outputted electromagnetic radiation.

14. A multibeam LiDAR system including:

a laser source having a laser cavity and configured to output electromagnetic radiation;

a pre-amplifier including quantum dots and positioned outside the laser cavity to receive the electromagnetic radiation output from the laser source;

wherein the pre-amplifier is configured to:

amplify the received electromagnetic radiation using the quantum dots; and

output the amplified electromagnetic radiation;

a beam splitter configured to split the amplified electromagnetic radiation and output the split electromagnetic radiation;

an array of optical amplifiers located on a single semiconductor chip, each of the optical amplifiers made from quantum dots and positioned outside the laser cavity to receive a portion of the split electromagnetic radiation;

wherein each of the array of optical amplifiers is configured to:

amplify the received split electromagnetic radiation using the quantum dots; and

output the amplified split electromagnetic radiation.

15. The multibeam LiDAR system of claim 14 , further comprising an array of splitters, each of the splitters positioned to receive amplified split electromagnetic radiation and configured to further split the amplified split electromagnetic radiation into multiple outputs.

16. The multibeam LiDAR system of claim 14 , wherein the array of optical amplifiers include four or more optical amplifiers.

17. The multibeam LiDAR system of claim 14 wherein each portion of the electromagnetic radiation emitted has an optical power of 200 mW or more.

18. A method for controlling amplification in a LiDAR system including a laser source and an optical amplifier made from quantum dots, the method comprising:

outputting electromagnetic radiation using the laser source;

receiving the outputted electromagnetic radiation with the optical amplifier;

amplifying the received electromagnetic radiation using the quantum dots; and

outputting the amplified electromagnetic radiation.

19. The method of claim 18 , wherein:

receiving the outputted electromagnetic radiation with the optical amplifier comprises receiving the outputted electromagnetic radiation with a pre-amplifier of the optical amplifier;

amplifying the received electromagnetic radiation using the quantum dots comprises:

amplifying the received electromagnetic radiation using the quantum dots of the pre-amplifier;

outputting the electromagnetic radiation amplified by the pre-amplifier;

a post-amplifier of the optical amplifier receiving the electromagnetic radiation amplified by the pre-amplifier; and

amplifying the received amplified electromagnetic radiation using the quantum dots of the post-amplifier;

outputting the amplified electromagnetic radiation comprises outputting the electromagnetic radiation amplified by the post-amplifier.

20. A laser amplification system comprising:

a laser source having a laser cavity and configured to output electromagnetic radiation; and

an optical amplifier including quantum dots and positioned outside the laser cavity to receive the electromagnetic radiation output from the laser source;

wherein the optical amplifier is configured to:

amplify the received electromagnetic radiation using the quantum dots; and

output the amplified electromagnetic radiation.