LASER CHARACTERISTIC PROCESSOR

• US 20200132591A1
• Filed: 10/31/2018
• Published: 04/30/2020
• Est. Priority Date: 10/31/2018
• Status: Active Grant

• Current Assignee: BAE Systems Information and Electronic Systems Integration Incorporated (BAE Systems Plc)
• Original Assignee: BAE Systems Information and Electronic Systems Integration Incorporated (BAE Systems Plc)
• Inventors: Lee, Bryan D., Palie, Christopher M., Radl, Andrew J.
• Granted Patent: US 10,739,247 B2
• Time in Patent Office: Days
• CPC Class Codes: G01D 5/32 with attenuation or whole or partial obturation of beams of light G01D5/40 takes precedence ; mechanical adjustment G01D5/264
• CPC Class Codes: G01J 1/0403 Mechanical elements; Supports for optical elements; Scanning arrangements
• CPC Class Codes: G01J 1/0411 using focussing or collimating elements, i.e. lenses or mirrors; Aberration correction
• CPC Class Codes: G01J 1/0414 using plane or convex mirrors, parallel phase plates, or plane beam-splitters
• CPC Class Codes: G01J 1/0488 with spectral filtering
• CPC Class Codes: G01J 1/4257 applied to monitoring the characteristics of a beam, e.g. laser beam, headlamp beam monitoring arrangements for lasers in general H01S3/0014
• CPC Class Codes: G01N 15/1436 the optical arrangement forming an integrated apparatus with the sample container, e.g. a flow cell
• CPC Class Codes: G01N 15/1459 the analysis being performed on a sample stream
• CPC Class Codes: G01N 2015/1447 Spatial selection
• CPC Class Codes: H01S 3/0014 Monitoring arrangements not otherwise provided for photometry G01J1/00, e.g. G01J1/4257; radiation pyrometry G01J5/00; measuring coherence of light G01J9/00; measuring wavelength of light G01J9/00, e.g. G01J9/0246; measuring optical pulses G01J11/00; calorimetrically measuring power of laser beams G01K17/003
• CPC Class Codes: H01S 3/2383 Parallel arrangements

Abstract

A system and process for testing and analyzing a laser beam is provided. The system and process allows for repeatable testing of a laser beam to provide a beam intensity profile while accounting for variation in measurements attributable to outside factors. The system and process further allows for simultaneous measurement and analysis of a laser beam having multiple wavelengths.

Claims

1. A method of collecting laser data comprising:

generating a reference laser beam from a reference laser generator;

reflecting the reference laser beam off a face of a beam director assembly to a detector;

recording the coordinates of the reference laser beam on the detector;

turning the reference laser generator off;

trasmitting a test laser beam from the beam director assembly to the detector; and

recording laser data from the test laser beam via the detector.

2. The method of claim 1 further comprising:

reflecting the reference laser beam off of an off-axis parabola between reflecting the reference laser beam off a face of the beam director assembly and reflecting the reference laser beam to the detector.

3. The method of claim 1 wherein the detector is a focal plane array.

4. The method of claim 1 further comprising:

passing the test laser beam from the beam director assembly through at least one spectral filter before it reaches the detector.

5. The method of claim 1 further comprising:

splitting the test laser beam from the beam director assembly into a first beam having a first beam path and a second beam having a second beam path after generating the test laser beam from the beam director assembly; and

,

directing the first beam of the test laser beam to a first detector and directing the second beam of the test laser beam to a second detector.

6. The method of claim 5 further comprising:

recording laser data from the first beam via the first detector; and

recording laser data from the second beam via the second detector.

7. The method of claim 6 wherein recording laser data from the first beam via the first detector and recording laser data from the second beam via the second detector occurs simultaneously.

8. The method of claim 6 wherein splitting the test laser beam is accomplished by an optical wedge.

9. The method of claim 8 wherein the optical wedge has a first quadrant, a second quadrant, a third quadrant, and a fourth quadrant, the method further comprising:

splitting the test laser beam into the first beam and second beam by directing the test laser beam to each of the first, second, third, and fourth quadrants of the optical wedge; and

recording the laser data from the first beam via the first detector and the second beam via the second detector for each test laser beam position from the first, second, third, and fourth quadrants of the optical wedge.

10. The method of claim 6 further comprising:

passing the first beam through at least one spectral filter before it reaches the first detector; and

,

passing the second beam through at least one spectral filter before it reaches the second detector.

11. A method of analyzing laser data comprising:

transmitting a test laser beam having at least two wavelengths from a beam director assembly to a detector;

recording the (x,y) coordinates of a beam spot centroid on the detector;

recording the (x,y) coordinates of a plurality of pixels in the detector;

calculating a radiant intensity profile of the test laser beam; and

,

comparing the radiant intensity profile of the test laser beam to a criteria profile to determine if the laser beam meets or exceeds the criteria profile.

12. The method of claim 11 further comprising:

rejecting the laser beam if it fails to meet the criteria profile or accepting the laser beam if it meets or exceeds the criteria profile.

13. The method of claim 11 wherein the detector is a focal plane array detector.

14. The method of claim 13 further comprising:

filtering the test laser beam to a single wavelength prior to reaching the detector; and

measuring the wavelength of the test laser beam at the detector.

15. The method of claim 14 wherein calculating the radiant intensity profile further comprises:

orienting an image of the test laser beam on the detector;

subtracting image bias from the detector image;

calculating the signal to noise ratio of the image;

calculating the pixel coordinates of the image centroid and the aperture energy radius;

calculating the beam diameter and the angular skew of the test laser beam;

calculating the intensity energy of the test laser beam;

comparing the intensity profile to an ideal Gaussian profile;

converting pixel data to an angular coordinate frame and a spatial coordinate frame; and

,

calculating the power factor of the test laser beam.

16. The method of claim 15 further comprising:

splitting the test laser beam into a first beam with a first beam path directed to a first detector and a second beam with a second beam path directed to a second detector prior to filtering the test laser beam;

filtering the first beam to a first wavelength prior to reaching the first detector;

filtering the second beam to a second wavelength prior to reaching the second detector; and

,

measuring the first wavelength at the first detector and the second wavelength at the second detector.

17. The method of claim 16 wherein splitting the test laser beam is accomplished by an optical wedge.

18. The method of claim 17 wherein the optical wedge has a first quadrant, a second quadrant, a third quadrant, and a fourth quadrant, the method further comprising:

splitting the test laser beam into the first beam and second beam by directing the test laser beam to each of the first, second, third, and fourth quadrants of the optical wedge; and

measuring the first wavelength at the first detector and the second wavelength at the second detector for each laser beam position from the first, second, third, and fourth quadrants of the optical wedge.

19. A method of collecting and analyzing laser beam data comprising:

generating a reference laser beam from a reference laser generator;

reflecting the reference laser beam off a face of a beam director assembly to a detector;

recording the coordinates of the reference laser beam on the detector;

turning the reference laser generator off;

transmitting a test laser beam having at least two wavelengths from the beam director assembly to the detector;

recording the (x,y) coordinates of a beam spot centroid on the detector;

recording the (x,y) coordinates of a plurality of pixels in the detector;

calculating a radiant intensity profile of the test laser beam; and

,

comparing the radiant intensity profile of the test laser beam to a criteria profile to determine if the test laser beam meets or exceeds the criteria profile.

20. The method of claim 19 wherein calculating the radiant intensity profile further comprises:

orienting an image of the test laser beam on the detector;

subtracting image bias from the detector image;

calculating the signal to noise ratio of the image;

calculating the pixel coordinates of the image centroid and the aperture energy radius;

calculating the beam diameter and the angular skew of the test laser beam;

calculating the intensity energy of the test laser beam;

comparing the intensity profile to an ideal Gaussian profile;

converting pixel data to an angular coordinate frame and a spatial coordinate frame; and

,

calculating the power factor of the test laser beam.