Coaxial direct-detection LIDAR-system

Patent metadata

Field	Value
Publication number	US-10598769-B2
Application number	US-201414889404-A
Country	US
Kind code	B2
Filing date	May 6, 2014
Priority date	May 6, 2013
Publication date	Mar 24, 2020
Grant date	Mar 24, 2020

Abstract

The invention relates to a coaxial direct-detection LIDAR system for measuring velocity, temperature and/or particulate density. The system comprises a laser source for emitting a laser light beam having a lasing center frequency along an emission path. The system further comprises an optical delivery system arranged in the emission path of the laser source, the optical delivery system being arranged for delivering the laser light beam in a measuring direction, the optical delivery system further being configured for collecting a return signal backscattered along the measuring direction. Finally, the system comprises a detector system arranged to receive the return signal from the optical delivery system, the detector system comprising a narrowband optical filter and a detector, the narrowband optical filter having a filter center frequency of a pass-band, wherein the center lasing frequency and/or the center filter frequency may be scanned. The invention further relates to an aircraft airspeed measurement device, and a wind turbine airspeed measurement device comprising the LIDAR system.

First claim

The invention claimed is:

1. A coaxial direct-detection LIDAR system for measuring velocity, temperature and/or particulate density, the system comprising:
a laser source for emitting a laser light beam having a lasing center frequency along an emission path,
an optical delivery system arranged in the emission path of the laser source, the optical delivery system being arranged for delivering the laser light beam in a measuring direction, the optical delivery system further being configured for collecting a return signal backscattered along the measuring direction, and
a detector system arranged to receive the return signal from the optical delivery system, the detector system comprising a narrowband optical filter and a detector, wherein the narrowband optical filter has a filter center frequency of a pass-band, and wherein the center filter frequency may be scanned.

2. The LIDAR system according to claim 1 , wherein the optical narrowband filter comprises a scanning Fabry-Perot interferometer.

3. The LIDAR system according to claim 1 , wherein the detector system further comprises an optical small signal pre-amplifier.

4. The LIDAR system according to claim 1 , wherein the detector is or comprises a photon-counting device.

5. The LIDAR system according to claim 1 , wherein the laser source is adapted for emitting infrared light with a wavelength of about 1.3 μm to about 1.8 μm, about 1.4 μm to about 1.7 μm, or about 1.5 μm to about 1.6 μm.

6. The LIDAR system according to claim 1 , wherein the laser source is adapted for emitting light with a wavelength of about 300 nm to about 1500 nm, about 350 nm to about 1200 nm, or about 400 nm to about 900 nm.

7. The LIDAR system according to claim 1 , wherein the laser source is or comprises a laser diode configured for directly emitting the laser light beam.

8. The LIDAR system according to claim 1 , wherein the laser source is adapted for generating laser light with an optical power from about 1 mW to about 500 mW, about 5 mW to about 100 mW, or about 8 mW to about 20 mW.

9. The LIDAR system according to claim 1 , wherein the laser source is pulsed.

10. The LIDAR system according to claim 1 , wherein the laser source is continuous wave, CW.

11. The LIDAR system according to claim 2 , wherein the Fabry-Perot interferometer has a free spectral range FSR in the range from about 0.5 GHz to about 10.0 GHz, about 0.8 GHz to about 6.0 GHz, or about 1.0 GHz to about 4.0 GHz.

12. The LIDAR system according to claim 2 , wherein the Fabry-Perot interferometer has a finesse F in the range from about 50 to about 5000, from about 100 to about 1000, or about 200 to about 600.

13. An aircraft airspeed measurement device, the device comprising the LIDAR system according to claim 1 .

14. A wind turbine airspeed measurement device, the device comprising the LIDAR system according to claim 1 .

Assignees

• Univ Danmarks Tekniske

Inventors

• Rodrigo Peter John
• Pedersen Christian

Classifications

• G01S7/4917

  superposing optical signals in a photodetector, e.g. optical heterodyne detection · CPC title

• G01S17/58

  Velocity or trajectory determination systems; Sense-of-movement determination systems · CPC title

• G01S17/95

  for meteorological use · CPC title

• G01S7/4812 Primary

  transmitted and received beams following a coaxial path · CPC title

• Y02A90/19

  Cross-Sectional Technologies · mapped topic