Multi-clad Fiber Based Optical Apparatus and Methods for Light Detection and Ranging Sensors

• US 20140168631A1
• Filed: 10/09/2013
• Published: 06/19/2014
• Est. Priority Date: 12/18/2012
• Status: Active Grant

• Current Assignee: Uatc, LLC (Uber Technologies, Inc.), Utac, LLC
• Original Assignee: Pouch Holdings LLC
• Inventors: HASLIM, James A., KARASOFF, Michael D., ITURRARAN, Nicholas M., SCHWARZ, Brent S.
• Granted Patent: US 9,823,351 B2
• Time in Patent Office: Days
• US Class Current: 356/4.01
• CPC Class Codes: G01S 17/06 Systems determining position data of a target
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 7/4812 transmitted and received beams following a coaxial path
• CPC Class Codes: G01S 7/4817 relating to scanning
• CPC Class Codes: G01S 7/4818 using optical fibres
• CPC Class Codes: G02B 6/262 Optical details of coupling light into, or out of, or between fibre ends, e.g. special fibre end shapes or associated optical elements

Abstract

Methods and apparatus for light detecting and range sensing. In one approach, a light detecting and ranging (LiDAR) sensor uses an optical directing device; a multi-clad optical fiber, a light source, and a detector. The light source is optically coupled to the multi-clad optical fiber which is configured to receive optical rays transmitted from the light source and route the rays on an optical path leading to the optical directing device. The optical directing device is configured both to direct the transmitted optical rays routed through the multi-clad fiber towards a target to be sensed and direct optical rays reflected from the target on an optical path leading to the multi-clad optical fiber. The multi-clad optical fiber is configured to receive the reflected optical rays and route the reflected optical rays on an optical path leading to the detector. The detector is configured to detect the reflected optical rays.

Claims

1. An optical apparatus for a light detecting and ranging (LiDAR) sensing system, the optical apparatus comprising

an optical directing device;

and

a multi-clad optical fiber, wherein said multi clad optical fiber comprises a core, at least one inner cladding, and an outer cladding;

wherein said core is arranged to receive optical rays transmitted from a light source of said sensing system and route said transmitted optical rays on an optical path leading to the optical directing device;

wherein said optical directing device is configured both to direct said routed transmitted rays on an optical path leading to a target to be sensed and direct reflected optical rays from said target on an optical path leading to said inner cladding of said optical fiber; and

wherein said inner cladding is configured to receive said reflected optical rays and route said reflected optical rays for receiving by a detector of said sensing system.

2. The optical apparatus of claim 1, further comprising an optical coupling device or system, wherein said optical coupling device or system is configured both to direct said transmitted optical rays from said light source on an optical pathway leading to said core of said multi clad optical fiber, and direct said reflected optical rays received from said inner cladding on an optical path leading to said detector.

3. A method for a light detecting and ranging (LiDAR) sensing system, the method comprising

receiving, in a core of a multi clad optical fiber, optical rays transmitted from a light source of said sensing system;

routing said transmitted optical rays through said core, directing said transmitted optical rays routed through said core on an optical path leading to a target to be sensed;

receiving reflected optical rays from said target and directing said reflected optical rays into an inner cladding of said optical fiber; and

routing said reflected optical rays through said inner cladding for receiving by a detector of said sensing system.

4. The method of claim 3, wherein the step of directing said transmitted optical rays routed through said core on to a target to be sensed comprises directing, utilizing an optical directing device, said transmitted optical rays routed through said core on to a target to be sensed;

and

wherein receiving reflected optical rays from said target and directing said reflected optical rays on an optical path leading towards an inner cladding of said optical fiber comprises receiving, by said optical directing device, said reflected optical rays from said target and directing, utilizing said optical directing device, said reflected optical rays on an optical path leading to an inner cladding of said optical fiber.

5. An optical apparatus for a light detecting and ranging (LiDAR) sensing system, the optical apparatus comprising

an optical directing device;

a multi clad optical fiber, wherein said multi clad optical fiber comprises a core, at least one inner cladding, and an outer cladding; and

an optical circulator;

wherein said optical circulator is arranged to direct optical rays transmitted from a light source of said sensing system on an optical path leading to said core and block said transmitted optical rays from reaching an optical path for a detector coupling the optical circulator;

wherein said core is arranged to receive said optical rays transmitted directed from said optical circulator and route said transmitted optical rays on an optical path leading to the optical directing device;

wherein said optical directing device is configured both to direct said routed transmitted rays on an optical path leading to a target to be sensed and direct reflected optical rays from said target on an optical path leading to said inner cladding of said optical fiber;

wherein said inner cladding is configured to receive said reflected optical rays and route said reflected optical rays for receiving by a detector of said sensing system; and

wherein said optical circulator is arranged to allow optical rays received and routed by said core on an optical path leading to said optical circulator to reach the optical path for a detector coupling the circulator.

6. A method for a light detecting and ranging (LiDAR) sensing system, the method comprising

directing, utilizing an optical circulator, optical rays transmitted from a light source of said sensing system on an optical path leading to a core of a multi clad optical fiber and blocking said transmitted optical rays from reaching a detector;

receiving, in said core of a multi clad optical fiber, said directed transmitted optical rays;

routing said transmitted optical rays through said core, directing said transmitted optical rays routed through said core on to a target to be sensed;

directing reflected optical rays from said target on an optical path leading to an inner cladding of said optical fiber;

routing said reflected optical rays through said inner cladding for receiving by a detector of said sensing system;

routing optical rays received in said core to said optical circulator;

utilizing said optical circulator, allowing optical rays routed by said core on an optical path leading to said optical circulator to reach said detector.

7. A light detecting and ranging (LiDAR) sensor device comprising

an optical directing device;

a multi clad optical fiber, wherein said multi clad optical fiber comprises a core, at least one inner cladding, and an outer cladding;

a light source;

a detector; and

an optical coupling operably coupling said light source to said core and operably coupling said detector to said inner cladding;

wherein said core is arranged to receive optical rays transmitted from said light source and route said transmitted optical rays on an optical path leading to the optical directing device;

wherein said optical directing device is configured both to direct said transmitted rays routed through said core on an optical path leading to a target to be sensed and direct optical rays reflected from said target on an optical path leading to said inner cladding of said optical fiber core;

wherein said inner cladding is configured to receive said reflected optical rays and route said reflected optical rays on an optical path leading to the detector; and

wherein said detector is configured to detect said reflected optical rays routed on an optical path leading towards said detector.

8. An optical apparatus for a light detection and ranging sensor;

the apparatus comprising an optical directing device, wherein the optical directing device is a refractive lens, or a diffractive lens, or a focusing mirror; and

further comprising at least one multi-clad optical fiber, wherein said multi-clad fiber is arranged to receive optical rays transmitted from at least one light source and route said transmitted optical rays on an optical path leading to the optical directing device;

wherein said optical directing device is configured both to direct said routed transmitted rays on an optical path leading to a target to be sensed and direct reflected optical rays from said target on an optical path leading to said optical fiber; and

wherein said fiber is configured to receive said reflected optical rays and route said reflected optical rays for receiving by at least one detector.

9. The optical apparatus of claim 8, further comprising an optical coupling device or system for the or each multi-clad fiber, wherein said optical coupling device or system is configured both to direct said transmitted optical rays from the at least one light source on an optical pathway leading to each multi-clad optical fiber, and direct the reflected optical rays received from each multi-clad fiber on an optical path leading to the at least one detector.

10. The optical apparatus of claim 9, wherein the optical coupling device or system is configured to air couple the at least one light source to the core of the or each multi-clad fiber and wherein said optical coupling device is configured to air couple the reflected optical rays received from each multi-clad fiber to a detector provided for each multi-clad fiber.

11. The optical apparatus of claim 10, wherein the optical coupling device of system further comprises an optical circulator arranged to direct the optical rays transmitted from the at least one light source on the optical path leading to the core of a multi-clad optical fiber;

and wherein the optical circulator is arranged to direct the optical rays reflected by the target and received by the optical directing device into and routed by the core of the multi-clad fiber on a path leading to either the detector provided for each multi-clad fiber or an additional detector provided for each circulator; and

wherein the circulator is arranged to block the transmitted optical rays from reaching the detector to which the received optical rays are directed.

12. The optical apparatus of claim 9, wherein the optical coupling device or system for the or each multi-clad fiber comprises an optical circulator and a multi-mode fiber for coupling the optical circulator to the at least one detector, wherein said optical circulator is arranged to direct the optical rays transmitted from the at least one light source on the optical path leading to the core of the or each multi-clad fiber and block the transmitted optical rays from reaching the at least one detector;

and wherein the optical circulator is arranged to direct the reflected optical rays routed by both the core and inner cladding of the or each multi-clad fiber, to said multi-mode fiber on a path leading to the at least one detector.

13. The optical apparatus of claim 9, wherein the optical coupling device or system for the or each multi-clad fiber comprises optical fibers operably coupled directly to the or each multi-clad fiber through splice or proximal location;

wherein one optical fiber couples from at least one light source to the core of the or each multi-clad fiber, and wherein at least one optical fiber couples from the inner cladding of the or each multi-clad fiber to at least one detector provided for the or each multi-clad fiber.

14. The optical apparatus of claim 13, wherein the optical coupling device or system for the or each multi-clad fiber further comprises an optical circulator arranged to direct the optical rays transmitted from the at least one light source to the fiber coupling the core of the or each multi-clad fiber and block the transmitted optical rays from reaching an additional detector provided for the or each circulator;

and wherein the optical circulator is arranged to direct optical rays reflected by the target and received by the optical directing device into and routed by the core of the multi-clad fiber on a path leading to the additional detector provided for the or each circulator.

15. The optical apparatus of claim 8, further comprising an optical coupling device or system, wherein the optical coupling device or system is configured to produce from the at least one light source a plurality of apparent light sources arrayed in a focal plane;

and further configured to place an equal plurality of multi-clad fiber ends to be coupled in a similar array; and

further configured to place an equal plurality of detectors in a similar array; and

wherein the optical coupling device or system is arranged to air couple via optical imaging, transmitted light rays from the apparent light sources into the cores of the multi-clad fibers, and received light rays from the ends of the multi-clad fibers onto a detector for the or each multi-clad fiber.

16. The optical apparatus of claim 15, further comprising a fiber optical circulator for each apparent light source;

wherein each fiber optical circulator is arranged to direct optical rays transmitted from the at least one light source to a fiber end that serves as each apparent light source, and block the transmitted optical rays from reaching an additional detector provided for each apparent light source; and

wherein each fiber optic circulator is arranged to direct optical rays reflected by the target and received by the optical directing device into and routed by the core of the multi-clad fiber on a path leading to the additional detector provided for each apparent light source.

17. The optical apparatus of claim 8, further comprising a transverse motion device, wherein the transverse motion device dynamically changes the position of the ends of the at least one multi-clad fiber that projects toward and receives from the optical directing device, relative to the position of the optical directing device, while substantially maintaining the focal relationship between the ends of the at least one multi-clad fiber and the optical directing device.

18. A LiDAR sensor comprising the optical apparatus of claim 8.

19. A LiDAR sensor comprising the apparatus of claim 17.

20. A method for light detection and ranging sensors, the method comprising receiving, in at least one multi-clad optical fiber, optical rays transmitted from at least one light source;

routing said transmitted optical rays through said fiber, directing said transmitted optical rays routed through said fiber on an optical path leading to a target to be sensed;

receiving reflected optical rays from said target and directing said reflected optical rays into said optical fiber; and

routing said reflected optical rays through said fiber for receiving by at least one detector.

21. The method of claim 20, wherein receiving, in at least one multi-clad optical fiber, optical rays transmitted from at least one light source comprises receiving, in the core of the or each multi-clad optical fiber, optical rays transmitted from at least one light source;

wherein routing said transmitted optical rays comprises routing said transmitted optical rays through the core of the or each multi-clad fiber, wherein directing said reflected optical rays into said fiber comprises directing said reflected optical rays into both the core and at least the inner cladding of the or each multi-clad optical fiber; and

wherein routing said reflected optical rays through said fiber comprises routing said reflected optical rays through both the core and at least the inner cladding of the or each multi-clad optical fiber.

22. The method of claim 21, wherein the step of directing said transmitted optical rays routed through said core on to a target to be sensed comprises directing, utilizing an optical directing device, said transmitted optical rays routed through said core on to a target to be sensed;

and wherein receiving reflected optical rays from said target and directing said reflected optical rays on an optical path leading towards both the core and at least the inner cladding of the or each multi-clad optical fiber comprises receiving, by said optical directing device, said reflected optical rays from said target and directing, utilizing said optical directing device, said reflected optical rays on an optical path leading to both the core and at least the inner cladding of said optical fiber;

wherein the optical directing device is either a refractive lens, a diffractive lens, or a focusing mirror.

23. The method of claim 21, further comprising directing, utilizing an optical circulator for the or each multi-clad fiber, said optical rays transmitted from said at least one light source on an optical path leading to said core and blocking said transmitted optical rays from reaching said at least one detector;

routing reflected optical rays through said core on an optical path leading to said optical circulator;

directing, utilizing said optical circulator, said reflected optical rays routed through said core on an optical path to said at least one detector.

24. The method of claim 21, further comprising directing, utilizing an optical circulator for the or each multi-clad fiber, said optical rays transmitted from said at least one light source on an optical path leading to said core and blocking said transmitted optical rays from reaching said at least one detector;

routing reflected optical rays through said both core and inner cladding on an optical path leading to said optical circulator;

directing, utilizing said optical circulator, said reflected optical rays, routed through said both core and inner cladding, through a multi-mode fiber on an optical path to said at least one detector.

25. The method of claim 22, further comprising dynamically moving the end or ends of the at least one multi-clad fiber that projects toward and receives from the optical directing device, relative to the position of the optical directing device while substantially maintaining the focal relationship between the fiber ends and the optical directing device, such that the optical rays projected toward the optical directing device substantially remain within the clear aperture of the optical directing device.