Wavelength Beam Combining Laser with Multiple Outputs

• US 20110310921A1
• Filed: 08/25/2011
• Published: 12/22/2011
• Est. Priority Date: 03/05/2010
• Status: Active Grant

• Current Assignee: Panasonic Corporation Of North America (Panasonic Holdings Corporation)
• Original Assignee: TeraDiode, Inc. (Panasonic Holdings Corporation)
• Inventors: Chann, Bien, Huang, Robin
• Granted Patent: US 8,670,180 B2
• Time in Patent Office: Days
• US Class Current: 372/70
• CPC Class Codes: G02B 19/0014 at least one surface having optical power
• CPC Class Codes: G02B 19/0028 refractive and reflective surfaces, e.g. non-imaging catadioptric systems
• CPC Class Codes: G02B 19/0057 in the form of a laser diode array, e.g. laser diode bar semiconductor laser arrays with beam combining arrangement H01S5/4012
• CPC Class Codes: G02B 27/0905 Dividing and/or superposing multiple light beams
• CPC Class Codes: H01S 3/094053 Fibre coupled pump, e.g. delivering pump light using a fibre or a fibre bundle
• CPC Class Codes: H01S 3/09408 Pump redundancy
• CPC Class Codes: H01S 3/094096 Multi-wavelength pumping
• CPC Class Codes: H01S 3/09415 the pumping beam being parallel to the lasing mode of the pumped medium, e.g. end-pumping
• CPC Class Codes: H01S 5/005 Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping H01S5/026, H01S5/18388 take precedence
• CPC Class Codes: H01S 5/4012 Beam combining, e.g. by the use of fibres, gratings, polarisers, prisms
• CPC Class Codes: H01S 5/4031 Edge-emitting structures
• CPC Class Codes: H01S 5/405 Two-dimensional arrays
• CPC Class Codes: H01S 5/4062 with an external cavity or using internal filters, e.g. Talbot filters
• CPC Class Codes: H01S 5/4087 emitting more than one wavelength

Abstract

A system and method for producing a multi-output laser by reconfiguring and apportioning a plurality of electromagnetic beams produced by various wavelength beam combining techniques. The reconfiguring of beams includes individual rotation and selective repositioning of one or more beams with respect to beam'"'"'s original input position.

Claims

1. A multi-output laser system comprising:

a wavelength beam combiner configured to produce a multi-wavelength asymmetrical beam profile;

an optical symmetrizing element configured to symmetrize the multi-wavelength asymmetrical beam profile; and

an optical apportioning element configured to apportion the symmetrized beam and direct each portion to a distinct location.

2. The multi-output laser system of claim 1, wherein the wavelength beam combiner includes:

a plurality of laser elements each configured to generate optical radiation having a unique wavelength, and wherein the plurality of laser elements are arranged in a two-dimensional array;

an optical imaging element configured to image each of the plurality of laser elements along a slow axis of the laser elements;

an optical focusing element arranged to intercept optical radiation from each of the plurality of laser elements and combine the optical radiation along the fast dimension of the laser elements to form a multi-wavelength asymmetrical beam profile; and

a diffraction element positioned at a region of overlap of the optical radiation to receive and transmit the multi-wavelength asymmetrical beam profile,

wherein the optical imaging element is configured to image each of the plurality of laser elements onto the diffraction element.

3. The multi-output laser system of claim 1, wherein the optical apportioning element is a plurality of reflective mirrors.

4. The multi-output laser system of claim 1, wherein the optical apportioning element is configured to focus at least one apportioned profile.

5. The multi-output laser system of claim 1, wherein at least one portion of the symmetrized beam is directed into an optical fiber.

6. The multi-output laser system of claim 1, wherein each apportionment is equal to or more symmetrized than the symmetrized beam it was apportioned from.

7. The multi-output laser system of claim 1, wherein the optical symmetrization element is an optical rotator configured to selectively rotate one or more beams within the multi-wavelength asymmetrical beam.

8. The multi-output laser system of claim 1, wherein the optical symmetrization element is a spatial repositioner configured to spatially reposition one or more beams with respect to other beams of the asymmetrical multi-wavelength beam profile.

9. The multi-output laser system of claim 2, wherein the optical radiation from at least one laser element is apportioned and directed into more than one distinct location.

10. The multi-output laser system of claim 1, wherein the beam combiner includes:

an optical rotator configured to selectively rotate beams emitted by a plurality of laser elements;

a transform optic configured to receive and combine the selectively rotated beams along a beam combining dimension; and

a dispersive element positioned to receive and transmit the combined beams, wherein an asymmetric output profile is formed.

11. The multi-output laser system of claim 10, wherein at least two of the laser elements have a fixed-position relationship.

12. The multi-output laser system of claim 1, wherein the beam combiner includes:

a spatial repositioning element configured to selectively reposition beams emitted by a plurality of laser elements;

a transform optic configured to receive and combine the selectively rotated beams along a beam combining dimension; and

a dispersive element positioned to receive and transmit the combined beams, wherein an asymmetric output profile is formed.

13. The multi-output laser system of claim 12, wherein the plurality of laser elements produces a two-dimensional profile and the spatial-repositioning element reduces the number of beams along a first dimension while increasing the number of beams across a second dimension.

14. The multi-output laser system of claim 12, wherein at least two of the laser elements have a fixed-position relationship.

15. The multi-output laser system of claim 12, wherein the optical apportioning element is further comprised of:

a first optical element configured to focus the asymmetric beam profile to a focal plane; and

a plurality of reflective elements placed in the focal path of the first optical element, wherein the reflective elements are configured to apportion and individually direct a portion of the asymmetric beam profile to a distinct location.

16. A method for pumping a fiber laser including:

symmetrizing an asymmetric multi-wavelength beam profile formed by a wavelength beam combiner;

apportioning the symmetrized multi-wavelength beam profile into a plurality of multi-beam profiles; and

directing each of the plurality of multi-beam profiles into an optical fiber.

17. The method of claim 16, wherein the wavelength beam combiner comprises:

an optical rotator configured to selectively rotate beams emitted by a plurality of laser elements;

a transform optic configured to receive and combine the selectively rotated beams along a beam combining dimension; and

a dispersive element positioned to receive and transmit the combined beams, wherein an asymmetric multi-wavelength beam profile is formed.

18. The wavelength beam combiner of claim 17, further including:

an output coupler configured to receive the asymmetric multi-wavelength beam profile from the dispersive element and reflect a portion of the output profile back into the laser elements.

19. The wavelength beam combiner of claim 17, wherein at least two of the laser elements have a fixed-position relationship.

20. The wavelength beam combiner of claim 17, wherein the laser elements include a first reflective surface and an optical gain medium.

21. The wavelength beam combiner of claim 17, further including a collimation optic configured to receive beams from the laser elements and collimate one or more beams along a dimension of the beam.

22. The wavelength beam combiner of claim 17, further including a spatial repositioning element configured to spatially-reposition one or more beams prior to being received by the transform optic.

23. The method of claim 16, wherein the wavelength beam combiner comprises:

a spatial repositioning element configured to spatially-reposition beams emitted by a plurality laser emitters;

a transform optic arranged to receive the spatially-repositioned beams and combine the beams along a beam combining dimension; and

a dispersive element positioned at a region of overlap of the combined beams to receive and transmit the combined beams.

24. The wavelength beam combiner of claim 23, wherein the plurality of laser elements produces a two-dimensional profile and the spatial-repositioning element reduces the number of beams along a first dimension while increasing the number of beams across a second dimension.

25. The wavelength beam combiner of claim 23, wherein at least two of the laser elements have a fixed-position relationship.

26. The wavelength beam combiner of claim 23, further including an optical rotator configured to selectively rotate beams prior to being received by the transform optic.

27. The method of claim 16, wherein symmetrizing the asymmetric multi-wavelength beam profile comprises rotating each beam of the profile in a range of 80 to 90 degrees.

28. The method of claim 16, wherein each optical fiber is coupled into a fiber laser system comprising a source laser and an optical gain medium.