Compact, thermally stable multi-laser engine

• US 9,014,224 B2
• Filed: 11/04/2010
• Issued: 04/21/2015
• Est. Priority Date: 04/04/2008
• Status: Active Grant

• Current Assignee: Idex Health & Science LLC (RELX PLC)
• Original Assignee: CVI Laser LLC
• Inventors: O'Shaughnessy, John, Hargis, David E., Miller, Steven Lee, Lin, Mark
• Primary Examiner(s): Niu, Xinning
• Application Number:
  US12/940,004
• Publication Number:
  US 20110134949A1
• Time in Patent Office: 1,629 Days
• Field of Search: 372/23, 372/34, 372/36, 372/50.121
• US Class Current: 372/34
• CPC Class Codes: G01N 2021/0346 Capillary cells; Microcells
• CPC Class Codes: G01N 21/0332 with temperature control control of temperature G05D23/00; cryostats F17C3/08
• CPC Class Codes: G01N 21/05 Flow-through cuvettes G01N21/09 takes precedence; handling fluid samples G01N1/10
• CPC Class Codes: G01N 21/255 Details, e.g. use of specially adapted sources, lighting or optical systems
• CPC Class Codes: H01S 3/005 Optical devices external to the laser cavity, specially adapted for lasers, e.g. for homogenisation of the beam or for manipulating laser pulses, e.g. pulse shaping shaping laser beam for working metal or other materials B23K26/06; optical elements, systems or apparatus in general G02B
• CPC Class Codes: H01S 3/025 of solid state lasers, e.g. housings or mountings
• CPC Class Codes: H01S 3/027 comprising a special atmosphere inside the housing
• CPC Class Codes: H01S 3/2383 Parallel arrangements
• CPC Class Codes: H01S 3/2391 emitting at different wavelengths

Abstract

Various embodiments of a multi-laser system are disclosed. In some embodiments, the multi-laser system includes a plurality of lasers, a plurality of laser beams, a beam positioning system, a thermally stable enclosure, and a temperature controller. The thermally stable enclosure is substantially made of a material with high thermal conductivity such as at least 5 W/(m K). The thermally stable enclosure can help maintain alignment of the laser beams to a target object over a range of ambient temperatures.

Claims

1. A compact, thermally stable multi-laser system, comprising:

a plurality of lasers outputting a plurality of respective laser beams;

a plurality of beam adjusters configured to align said laser beams output from said plurality of lasers thereby outputting a plurality of adjusted laser beams;

a beam positioning system configured to alter a position of the plurality of adjusted laser beams relative to one another, thereby outputting a plurality of positioned and adjusted laser beams;

a thermally stable enclosure enclosing the plurality of lasers and the beam positioning system, the thermally stable enclosure substantially comprising a material having a thermal conductivity of at least 5 W/(m K), the thermally stable enclosure configured to maintain alignment of said laser beams output from the lasers over a range of ambient temperatures, wherein the plurality of positioned and adjusted laser beams are output as parallel laser beams to a target object located outside the enclosure; and

a temperature controller configured to control the temperature of the thermally stable enclosure.

2. The system of claim 1, wherein the thermally stable enclosure is configured to thermally and mechanically couple to the target object.

3. The system of claim 1, wherein the temperature controller is configured to control the temperature of the target object.

4. The system of claim 1, wherein the target object comprises a flow cell.

5. The system of claim 2, wherein the thermally stable enclosure has a coefficient of thermal expansion and wherein a mounting mechanism for the target object has a thermal expansion coefficient that closely matches the coefficient of thermal expansion of the thermally stable enclosure.

6. The system of claim 1, wherein the target object comprises an optical fiber.

7. The system of claim 6, wherein the thermally stable enclosure encloses a portion of the optical fiber.

8. The system of claim 6, wherein the thermally stable enclosure has a coefficient of thermal expansion and wherein a mounting system for the optical fiber has a thermal expansion coefficient that closely matches the coefficient of thermal expansion of the thermally stable enclosure.

9. The system of claim 6, wherein said laser beams output from said lasers are co-linear at the optical fiber.

10. The system of claim 1, wherein the target object comprises an optical fiber in an adjuster mount configured to couple said laser beams output from said lasers into the optical fiber.

11. The system of claim 10, wherein the thermally stable enclosure has a coefficient of thermal expansion and wherein the adjuster mount has a thermal expansion coefficient that closely matches the coefficient of thermal expansion of the thermally stable enclosure.

12. The system of claim 10, wherein said laser beams output from the lasers are co-linear at the adjuster mount.

13. The system of claim 1, wherein relative heights of the lasers are configured to assist in relative positioning of said laser beams output from said lasers at the target object.

14. The system of claim 1, wherein said laser beams output from the lasers have centers separated by between about 100 μ

m and about 500 μ

m of one another at the target object.

15. The system of claim 1, wherein the thermally stable enclosure encloses beam focusing optics configured to focus said plurality of laser beams output by the lasers.

16. The system of claim 15, wherein the beam focusing optics includes an achromatic and anamorphic lens system configured to provide a laser beam with an elliptical shape at the target object.

17. The system of claim 15, wherein the beam focusing optics includes an achromatic spherical lens configured to provide a laser beam with an elliptical shape at the target object.

18. The system of claim 15, wherein the beam focusing optics includes an anamorphic prism system configured to provide a laser beam with an elliptical shape at the target object.

19. The system of claim 15, wherein the focused laser beams have respective focused spot sizes of between about 50 μ

m and about 150 μ

m in one direction.

20. The system of claim 15, wherein the focused laser beams have respective focused spot sizes of between 5 μ

m and 25 μ

m in a first direction.

21. The system of claim 1, wherein the plurality of lasers comprises at least one diode laser.

22. The system of claim 1, wherein the plurality of lasers comprises at least one solid-state laser.

23. The system of claim 1, wherein the plurality of lasers comprises at least one frequency-doubled laser.

24. The system of claim 1, wherein said plurality of laser beams output by the lasers comprises at least a first laser beam at a first wavelength, a second laser beam at a second wavelength different from the first wavelength, and a third laser beam at a third wavelength different from the first wavelength and the second wavelength.

25. The system of claim 1, wherein the beam positioning system comprises a plurality of wavelength selective mirrors configured to reflect at least one wavelength and to transmit at least one other wavelength.

26. The system of claim 1, wherein the beam positioning system comprises one or more prisms with wavelength selective surfaces configured to reflect at least one wavelength and to transmit at least one other wavelength.

27. The system of claim 1, further comprising flexure mounts supporting the beam positioning system.

28. The system of claim 1, wherein the plurality of beam adjusters is configured to align said laser beams output from said plurality of lasers prior to entering the beam positioning system.

29. The system of claim 1, wherein at least one of yaw, pitch, and separation between at least one of said beam adjusters is adjustable.

30. The system of claim 1, wherein said plurality of beam adjusters comprises a plurality of plane parallel plates configured to shift the laser beams in at least one direction.

31. The system of claim 30, wherein at least one of said plane parallel plates is adjustable.

32. The system of claim 1, further comprising an automatic power control module in communication with each said laser.

33. The system of claim 1, wherein at least one of a polarization rotator or a waveplate is used to rotate a laser beam polarization of at least one of said laser beams to obtain a laser beam polarization orientation that enhances system performance.

34. The system of claim 1, wherein the temperature controller is configured to hold a temperature within the thermally stable enclosure within about ±

3°

C. of a target temperature.

35. The system of claim 34, wherein the target temperature is between about 10°

C. and about 50°

C.

36. The system of claim 34, wherein the thermally stable enclosure is configured to thermally couple to the target object.

37. The system of claim 1, wherein the thermally stable enclosure is hermetically sealed.

38. The system of claim 1, wherein the temperature controller comprises a thermal electric cooler, a temperature sensor, and control electronics.

39. The system of claim 1, wherein the range of ambient temperatures is between about 10°

C. and about 55°

C.

40. The system of claim 1, wherein the thermally stable enclosure has a volume of 216 in³or less.

41. The system of claim 1, wherein the target object comprises a light pipe.

42. The system of claim 1, wherein the target object comprises a waveguide.

43. The system of claim 1, wherein the target object comprises a lab on a chip.

44. The system of claim 1, further comprising glue-block mounts supporting the beam positioning system.

48. The system of claim 20, wherein the focused laser beams have respective focused spot sizes of between about 50 μ

m and about 150 μ

m in a second direction orthogonal to the first direction.

49. The system of claim 1, wherein the laser beams are collimated at the target object, wherein the laser beams are parallel at the target object, and wherein the laser beams have centers separated by substantially equal separations at the target object.

50. The system of claim 1, wherein the laser beams are collimated at the target object, wherein the laser beams are parallel at the target object, and wherein the laser beams have centers separated by different separations at the target object.

51. The system of claim 1, wherein the parallel laser beams are focused at the target object, and wherein the laser beams have centers seperated by substantially equal separations at the target object.

52. The system of claim 1, wherein said plurality of beam adjusters comprises a plurality of rotatable Risley prism pairs configured to change the angle of said laser beams output from said plurality of lasers.

57. The system of claim 1, wherein the laser beams are focused at the target object, wherein the laser beams are parallel at the target object, and wherein the laser beams have centers seperated by different separations at the target object.

45. A method of adjusting a plurality of laser beams, the method comprising:

using a plurality of beam adjusters to redirect the plurality of laser beams by changing beam angles of the plurality of laser beams thereby outputting a plurality of adjusted laser beams;

using a plurality of plane parallel plates to change the lateral position of the plurality of adjusted laser beams, thereby outputting a plurality of positioned and adjusted laser beams; and

using a beam positioning system to alter a position of the plurality of positioned and adjusted laser beams closer together, thereby outputting parallel laser beams.

46. The system of claim 45, wherein the beam positioning system comprises a plurality of wavelength selective mirrors.

53. The method of claim 45, wherein the plurality of laser beams are output from a plurality of light sources.

54. The method of claim 45, wherein the method comprises using said plane parallel plates to change the lateral position of the plurality of adjusted laser beams after using said plurality of beam adjusters to redirect the plurality of laser beams by changing the beam angles of the plurality of laser beams, and comprises using said beam positioning system to reposition the plurality of positioned and adjusted laser beams closer together after using said plane parallel plates to change the lateral position of the plurality of adjusted laser beams.

55. The system of claim 45, wherein the plurality of beam adjusters comprises a plurality of rotatable Risley prism pairs.

47. A compact, thermally stable laser system, comprising:

a laser outputting a laser beam;

a beam adjuster configured to alter a position of the laser beam, wherein the beam adjuster comprises a rotatable Risley prism pair configured to change the angle of said laser beam output from said laser, thereby outputting an adjusted laser beam;

a thermally stable enclosure enclosing the laser and the beam adjuster, the thermally stable enclosure substantially comprising a material having a thermal conductivity of at least 5 W/(m K), the thermally stable enclosure configured to maintain alignment of the adjusted laser beam to a target object located outside the enclosure over a range of ambient temperatures; and

a temperature controller configured to control the temperature of the thermally stable enclosure.

56. A compact, thermally stable multi-laser system, comprising:

a plurality of lasers outputting a plurality of respective laser beams;

a plurality of beam adjusters configured to align said laser beams output from said plurality of lasers thereby outputting a plurality of adjusted laser beams;

a beam positioning system configured to alter a position of the plurality of adjusted laser beams relative to one another, thereby outputting a plurality of positioned and adjusted laser beams;

a thermally stable enclosure enclosing the plurality of lasers and the beam positioning system, the thermally stable enclosure substantially comprising a material having a thermal conductivity of at least 5 W/(m K), the thermally stable enclosure configured to maintain alignment of said laser beams output from the lasers over a range of ambient temperatures, wherein the plurality of positioned and adjusted laser beams are output as separate laser beams to a target object located outside the enclosure; and

a temperature controller configured to control the temperature of the thermally stable enclosure.