Laser for coherent LIDAR

• US 7,894,044 B1
• Filed: 03/11/2009
• Issued: 02/22/2011
• Est. Priority Date: 03/11/2008
• Status: Expired due to Fees

• Current Assignee: Oceanit Laboratories, Inc.
• Original Assignee: Oceanit Laboratories, Inc.
• Inventors: Sullivan, Christopher J.
• Primary Examiner(s): ALSOMIRI, ISAM A
• Application Number:
  US12/381,388
• Time in Patent Office: 713 Days
• Field of Search: 356 401- 501, 356/28
• US Class Current: 356/4.01
• CPC Class Codes: G01S 17/95 for meteorological use
• CPC Class Codes: G01S 7/4818 using optical fibres
• CPC Class Codes: Y02A 90/10 Information and communication technologies [ICT] supporting adaptation to climate change, e.g. for weather forecasting or climate simulation

Abstract

A method for achieving optimum coaxial lidar configuration using optical fibers. Optical fibers are used with mirrors or lenses to create light paths that can achieve an optimum lidar configuration while employing fewer components than that of prior art for a more simplified, lightweight, and less expensive system to produce. The lidar components, including the laser source and the light detector unit, may be placed in a separate housing. A separate housing eliminates unnecessary weight in the optical telescope assembly, makes scanning of the system easier, and enables a better omni-directional cloud height indicator.

Claims

1. A lidar apparatus comprising:

a source of transmitted light,

a transmitting optical fiber for carrying transmitted light from the source to a transmitting optical fiber end and out of the transmitting optical fiber end,

a first collimating lens in the path of the transmitted light,

a second collimating lens in the path of received light,

a receiving optical fiber end on a receiving optical fiber for receiving the received light from the second collimating lens and carrying the received light to a detector, and

wherein the transmitted light and the received light are coaxial exiting and entering the apparatus.

2. The apparatus of claim 1, wherein the source is a laser.

3. The apparatus of claim 1, wherein the first collimating lens is smaller than the second collimating lens and is placed in an opening in the center of the second collimating lens.

4. The apparatus of claim 1, further comprising a collimating optical subsystem wherein the collimating optical subsystem is supported by the second collimating lens.

5. A lidar apparatus comprising:

a source of transmitted light,

a transmitting optical fiber for carrying transmitted light from the source to a transmitting optical fiber end and out of the transmitting optical fiber end,

a first optical device in the path of the transmitted light,

a second optical device in the path of received light,

a receiving optical fiber end on a receiving optical fiber for receiving the received light and carrying the received light to a detector, and

wherein the transmitted light and received light are coaxial exiting and entering the apparatus.

6. The apparatus of claim 5, wherein the source is a laser.

7. The apparatus of claim 5, wherein the receiving optical fiber end is inverted with respect to the direction of travel of the transmitted light out of the apparatus and is closer to the first optical device than the receiving optical fiber end.

8. The apparatus of claim 7, wherein the first optical device is a collimating lens and the second optical device is a parabolic or spherical mirror.

9. The apparatus of claim 5, wherein the transmitting optical fiber end and the receiving optical fiber end are inverted with respect to the direction of travel of the transmitted light out of the apparatus and the transmitting optical fiber end is closer to the first optical device than the receiving optical fiber end.

10. The apparatus of claim 9, wherein the second optical device is a collimating mirror and the first optical device is a smaller collimating mirror placed in an opening in the center of the second optical device.

11. The apparatus of claim 9, further comprising an axion or waxicon between the transmitting optical fiber and the first optical device for offsetting the brightest portion of the transmitted light axially outward.

12. The apparatus of claim 5, wherein the first optical device is a collimating lens, the second optical device is a parabolic or spherical mirror and further comprising a third optical device.

13. The apparatus of claim 12, wherein the third optical device is a collimating assembly with a mirror on a back surface of the collimating assembly.

14. The apparatus of claim 12, wherein the third optical device is a mirror placed between the transmitting optical fiber end and the receiving optical fiber end for reflecting received light from the second optical device into the receiving optical fiber end.

15. The apparatus of claim 14, wherein a top surface of the third optical device is an off angle mirror, and wherein the transmitting optical fiber end is inverted and off angle with respect to the direction of travel of the transmitted light leaving the apparatus.

16. The apparatus of claim 14, wherein a top surface of the third optical device is a flat mirror, wherein the transmitting optical fiber end is inverted with respect to the direction of travel of the transmitted light leaving the apparatus.

17. The apparatus of claim 5, wherein the second optical device is a parabolic or spherical ring mirror, the first optical device is a parabolic or spherical mirror within an opening of the parabolic or spherical ring mirror, and wherein the transmitting optical fiber end and the receiving optical fiber end are located on opposite sides of the apparatus.

18. The apparatus of claim 5, wherein the second optical device is a flat ring mirror, the first optical device is a flat mirror within an opening of the flat ring mirror, and wherein the transmitting optical fiber end and the receiving optical fiber end are located on opposite sides of the apparatus.

19. The apparatus of claim 18, further comprising a collimating lens for affecting the transmitted light and the received light.

20. A lidar method comprising:

providing transmitted light from a source, through a transmitting optical fiber and to a transmitting optical fiber end,

passing the transmitted light to a first optical device and out of the apparatus,

receiving received light at a second optical device,

passing the received light to a receiving optical fiber end, through a receiving optical fiber and to a detector, and

wherein the transmitted light and received light are coaxial exiting and entering the apparatus.