Laser diode apparatus utilizing reflecting slow axis collimators

• US 8,891,579 B1
• Filed: 12/16/2011
• Issued: 11/18/2014
• Est. Priority Date: 12/16/2011
• Status: Active Grant

• Current Assignee: Nlight Inc.
• Original Assignee: nLIGHT Corporation
• Inventors: Price, Kirk, Lerner, Scott
• Primary Examiner(s): Matthews, Colleen A
• Assistant Examiner(s): FORDE, DELMA ROSA
• Application Number:
  US13/328,877
• Time in Patent Office: 1,068 Days
• Field of Search: 372/107, 372/92, 372/99, 372/50.12
• US Class Current: 372/107
• CPC Class Codes: H01S 5/02255 using beam deflecting elements
• CPC Class Codes: H01S 5/40 Arrangement of two or more semiconductor lasers, not provided for in groups H01S5/02 - H01S5/30 H01S5/50 takes precedence
• CPC Class Codes: H01S 5/4012 Beam combining, e.g. by the use of fibres, gratings, polarisers, prisms
• CPC Class Codes: H01S 5/4025 Array arrangements, e.g. constituted by discrete laser diodes or laser bar H01S5/42 takes precedence
• CPC Class Codes: H01S 5/4075 Beam steering
• CPC Class Codes: H01S 5/42 Arrays of surface emitting lasers

Abstract

A laser diode apparatus including a mounting block, a plurality of diode lasers mounted to the mounting block and each capable of emitting a respective diode laser beam, and a plurality of cylindrical mirrors each having a reflective back surface for providing slow axis collimation of an incident diode laser beam via reflection off the back surface, each one of the plurality of cylindrical mirrors optically coupled to a respective diode laser of the plurality of diode lasers and optically oriented therewith so as to be capable of providing the diode laser beams in a stacked arrangement.

Claims

1. A laser diode apparatus comprising:

a mounting block;

a plurality of diode lasers, each mounted to said mounting block and each capable of emitting a respective diode laser beam; and

a plurality of mirrors each for providing slow axis collimation and reflective direction of an incident corresponding one diode laser beam, each one of said plurality of mirrors optically coupled to at least one respective diode laser of said plurality of diode lasers and optically oriented therewith so as to be capable of reflectively providing the diode laser beams in a stacked arrangement;

wherein each of said mirrors is capable of providing slow axis and fast axis pointing correction of the respective diode laser beams via rotation, displacement, or rotation and displacement of said each mirror with respect to one or more axes associated therewith or associated with the respective diode laser beams.

2. The apparatus of claim 1 wherein each of said mirrors is made with two curved spherical or aspherical surfaces, providing three effective surfaces for spherical and comatic aberration correction.

3. The apparatus of claim 1 wherein each of said mirrors includes a highly reflective front surface.

4. The apparatus of claim 1 wherein each of said mirrors includes a front surface having an aspheric shape.

5. The apparatus of claim 1 wherein the stacked arrangement is aligned with a fast axis of the diode laser beams such that the laser beams point in the same direction in the fast axis.

6. The apparatus of claim 1 wherein said mounting block includes a plurality of adjacent flat mounting surfaces wherein each corresponding one of said plurality of diode lasers is mounted thereon, each one mounting surface of said plurality of mounting surfaces being vertically stepped with respect to each one adjacent mounting surface in a direction laterally perpendicular to the emission direction of said plurality of diode lasers.

7. The apparatus of claim 6 wherein the stacked arrangement of diode laser beams has a beam order corresponding to the order of said plurality of diode lasers mounted to said plurality of mounting surfaces.

8. The apparatus of claim 1 wherein said mounting block is heat dissipative.

9. The apparatus of claim 1 wherein each of said mirrors is cylindrical.

10. The apparatus of claim 1 wherein each of said mirrors is aspheric.

11. The apparatus of claim 1 further comprising:

a housing, including a bottom housing mounting surface;

wherein said mounting block is mounted to said bottom housing mounting surface, and;

wherein said plurality of mirrors is mounted to said bottom housing mounting surface.

12. The apparatus of claim 1 further comprising a plurality of fast axis collimators each optically coupled to a corresponding one of said plurality of diode lasers.

13. The apparatus of claim 1 further comprising a focusing optic for focusing the stacked arrangement of diode laser beams.

14. The apparatus of claim 13 further comprising a module output optically coupled to said focusing optic, wherein the stacked arrangement of diode laser beams is capable of becoming focused into said module output.

15. The apparatus of claim 14 wherein said module output is an optical fiber, a beam homogenization rod, beam homogenization optics, or free-space beam delivery optics.

16. The apparatus of claim 1 wherein said plurality of mirrors provides correction for off-axis aberrations.

17. A laser diode apparatus comprising:

a mounting block;

a plurality of diode lasers, each mounted to said mounting block and each capable of emitting a respective diode laser beam; and

a plurality of mirrors each for providing slow axis collimation and reflective direction of an incident corresponding one diode laser beam, each one of said plurality of mirrors optically coupled to at least one respective diode laser of said plurality of diode lasers and optically oriented therewith so as to be capable of reflectively providing the diode laser beams in a stacked arrangement;

wherein each of said mirrors includes an anti-reflective front surface and a highly reflective back-surface and an interior propagation region.

18. A laser diode apparatus comprising:

a mounting block;

a plurality of diode lasers, each mounted to said mounting block and each capable of emitting a respective diode laser beam; and

a plurality of mirrors each for providing slow axis collimation and reflective direction of an incident corresponding one diode laser beam, each one of said plurality of mirrors optically coupled to at least one respective diode laser of said plurality of diode lasers and optically oriented therewith so as to be capable of reflectively providing the diode laser beams in a stacked arrangement;

wherein each of said mirrors includes two cylindrical cuts defining a front surface and said reflective back surface, said front surface including one or more anti-reflection coatings applied thereto, said reflective back surface including one or more high reflection coatings applied thereto, and wherein said anti-reflection and high reflection coatings significantly reduce optical aberrations.