Multi-clad fiber-based light detection and ranging sensor
View Patent ↗A light detection and ranging (LiDAR) sensor includes a single-mode fiber positioned to receive the outputted light from a laser. The LiDAR also includes an optical circulator, a multi-clad fiber, a first optical detector positioned to receive reflected light from an inner cladding of the multi-clad fiber, and a second optical detector positioned to receive the reflected light from a core of the multi-clad fiber.
1. A light detection and ranging (LiDAR) sensor comprising:
a laser outputting laser light;
a single-mode fiber positioned to receive the laser light from the laser;
an optical circulator comprising a first port, a second port, and a third port, the optical circulator configured to direct the laser light from the first port to the second port and from the second port to the third port, the optical circulator receiving the laser light from the single-mode fiber at the first port;
a multi-clad fiber comprising a core, an inner cladding, and an outer cladding, the core receiving the laser light from the second port of the optical circulator and directing the laser light from the second port to a target, the inner cladding and the core receiving reflected light from the target;
a first optical detector positioned to receive the reflected light from the inner cladding of the multi-clad fiber and not the core of the multi-clad fiber; and
a second optical detector positioned to receive the reflected light from the core of the multi-clad fiber and not the inner cladding of the multi-clad fiber.
2. The LiDAR sensor of claim 1 , wherein the core of the multi-clad fiber transmits the reflected light to the second port of the optical circulator.
3. The LiDAR sensor of claim 2 , further comprising:
a multi-mode fiber coupled to the third port of the optical circulator and receiving the reflected light from the second port of the optical circulator, the multi-mode fiber transmitting the reflected light to the second optical detector.
4. The LiDAR sensor of claim 1 , further comprising:
an optical directing device focusing the laser light from the core of the multi-clad fiber toward the target, and focusing the reflected light from the target to the inner cladding and the core of the multi-clad fiber.
5. The LiDAR sensor of claim 4 , wherein the optical directing device comprises a lens.
6. The LiDAR sensor of claim 4 , wherein the optical directing device comprises a mirror.
7. The LiDAR sensor of claim 4 , wherein the optical directing device comprises at least one lens, and wherein the laser light to the target and the reflected light from the target are both directed by the at least one lens.
8. The LiDAR sensor of claim 4 , wherein the optical directing device comprises at least one mirror, and wherein the laser light to the target and the reflected light from the target are both directed by the at least one mirror.
9. The LiDAR sensor of claim 4 , further comprising:
a transverse motion device configured to dynamically change a position of the multi-clad fiber relative to the optical directing device.
10. The LiDAR sensor of claim 9 , wherein the optical directing device focuses the laser light from the multi-clad fiber to the target and focuses the reflected light from the target to the multi-clad fiber, and wherein the dynamically changing position of the multi-clad fiber substantially maintains a focal relationship with the optical directing device.
11. The LiDAR sensor of claim 9 , wherein the transverse motion device oscillates the multi-clad fiber at a frequency between 5 Hz and 5000 Hz.
12. The LiDAR sensor of claim 1 , wherein the first and the second optical detectors comprise avalanche photodiodes.
13. A compound light detection and ranging (LiDAR) sensor comprising a plurality of LiDAR sensors, each of the plurality LiDAR sensors comprising:
a laser outputting laser light;
a single-mode fiber positioned to receive the laser light from the laser;
an optical circulator comprising a first port, a second port, and a third port, the optical circulator configured to direct the laser light from the first port to the second port and from the second port to the third port, the optical circulator receiving the laser light from the single-mode fiber at the first port;
a multi-clad fiber comprising a core, an inner cladding, and an outer cladding, the core receiving the laser light from the second port of the optical circulator and directing the laser light from the second port to a target, the inner cladding and the core receiving reflected light from the target;
a first optical detector positioned to receive the reflected light from the inner cladding of the multi-clad fiber and not the core of the multi-clad fiber; and
a second optical detector positioned to receive the reflected light from the core and not the inner cladding of the multi-clad fiber.
14. The compound LiDAR sensor of claim 13 , wherein the core of the multi-clad fiber transmits the reflected light to the second port of the optical circulator.
15. The compound LiDAR sensor of claim 14 , each of the plurality LiDAR sensors further comprising:
a multi-mode fiber coupled to the third port of the optical circulator and receiving the reflected light from the second port of the optical circulator, the multi-mode fiber transmitting the reflected light to the second optical detector.
16. The compound LiDAR sensor of claim 13 , each of the plurality LiDAR sensors further comprising:
an optical directing device focusing the laser light from the core of the multi-clad fiber toward the target, and focusing the reflected light from the target to the inner cladding and the core of the multi-clad fiber.
17. The compound LiDAR sensor of claim 16 , wherein the optical directing device comprises a lens.
18. The compound LiDAR sensor of claim 16 , wherein the optical directing device comprises a mirror.
19. The compound LiDAR sensor of claim 16 , wherein the optical directing device comprises at least one lens, and wherein the laser light to the target and the reflected light from the target are both directed by the at least one lens.
20. An optical apparatus comprising:
a light source outputting light;
a single-mode fiber positioned to receive the outputted light from the light source;
an optical circulator comprising a first port, a second port, and a third port, the optical circulator configured to direct the outputted light from the first port to the second port and from the second port to the third port, the optical circulator receiving the outputted light from the single-mode fiber at the first port;
a multi-clad fiber comprising a core, an inner cladding, and an outer cladding, the core receiving the outputted light from the second port of the optical circulator and directing the outputted light from the second port to a target, the inner cladding and the core receiving reflected light from the target;
a first optical detector positioned to receive the reflected light from the inner cladding of the multi-clad fiber and not the core of the multi-clad fiber; and
a second optical detector positioned to receive the reflected light from the core of the multi-clad fiber and not the inner cladding of the multi-clad fiber.