Optical Pumping of Solid-State Laser Material Using Addressable Laser Array

• US 20120128015A1
• Filed: 11/18/2011
• Published: 05/24/2012
• Est. Priority Date: 11/19/2010
• Status: Active Grant

• Current Assignee: Lumentum Operations, LLC (Lumentum Holdings Inc.)
• Original Assignee: TriLumina Corp
• Inventors: Joseph, John R.
• Granted Patent: US 8,520,713 B2
• Time in Patent Office: Days
• US Class Current: 372/22
• CPC Class Codes: H01S 3/0621 Coatings on the end-faces, e.g. input/output surfaces of the laser light
• 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 3/101 Lasers provided with means to change the location from which, or the direction in which, laser radiation is emitted
• CPC Class Codes: H01S 3/1022 by controlling the optical pumping
• CPC Class Codes: H01S 3/109 Frequency multiplication, e.g. harmonic generation
• CPC Class Codes: H01S 5/4075 Beam steering
• CPC Class Codes: H01S 5/423 having a vertical cavity

Abstract

An array of Surface Emitting Laser (SEL) elements can be used to efficiently pump a disk or rod of solid-state laser glass or crystal, or harmonic-generating crystal. Placing the laser array chip against or near the surface of this solid-state material provides very high and uniform optical power density without the need for lenses or fiber-optics to conduct the light from typical edge-emitting lasers, usually formed in a stack of bars. The lasers can operate in multi-mode output for highest output powers. Photolithography allows for an infinite variety of connection patterns of sub-groups of lasers within the array, allowing for spatial contouring of the optical pumping power across the face of the solid-state material. The solid-state material may be pumped either within (intra-cavity) or externally (extra-cavity) to the SEL laser array.

Claims

1. A pumped solid-state laser, comprising:

a solid-state lasing material; and

an addressable array of surface emitting laser (SEL) elements arranged adjacent to the solid-state lasing material and configured to pump the solid-state lasing material to produce one or more laser beams as an output of the solid-state lasing material.

2. The pumped solid-state laser as recited in claim 1, wherein one or more SEL elements of the addressable array of SEL elements are configured to be addressed by a controller.

3. The pumped solid-state laser as recited in claim 1, wherein a controller is configured to address one or more SEL elements of the addressable array of SEL elements to control an intensity profile of the one or more laser beams.

4. The pumped solid-state laser as recited in claim 1, wherein a controller is configured to address one or more SEL elements of the addressable array of SEL elements to control a size of the one or more laser beams.

5. The pumped solid-state laser as recited in claim 1, wherein a controller is configured to address one or more SEL elements of the addressable array of SEL elements to control a shape of the one or more laser beams.

6. The pumped solid-state laser as recited in claim 1, wherein a controller is configured to address one or more SEL elements of the addressable array of SEL elements to control a propagation direction of the one or more laser beams.

7. The pumped solid-state laser as recited in claim 1, wherein the addressable array of SEL elements is a monolithic array.

8. The pumped solid-state laser as recited in claim 1, the solid-state lasing material having a first side facing the addressable array of SEL elements including a first set of one or more optical coatings that are transmissible to a pumping wavelength of the array of SEL elements and reflective to a solid-state wavelength of the solid-state lasing material, the solid-state lasing material having a second side facing away from the array of SEL elements including a second set of one or more optical coatings that are transmissible to the solid-state wavelength and reflective to the pumping wavelength, and further comprising a cavity mirror placed adjacent to the second side of the solid-state lasing material, the cavity mirror having an input side including a third set of one or more optical coatings that are reflective to the solid-state wavelength and an output side including a fourth set of one or more optical coatings that are partially transmissive to the solid-state wavelength.

9. The pumped solid-state laser as recited in claim 1, the solid-state lasing material having a first side facing the array of SEL element including a first set of one or more optical coatings that are transmissible to a pumping wavelength of the array of SEL elements and reflective to a solid-state wavelength of the solid-state lasing material, the solid-state lasing material having a second side facing away from the array of SEL elements including a second set of one or more optical coatings that are transmissible to the solid-state wavelength and reflective to the pumping wavelength, and further comprising a harmonic generating crystal material placed adjacent to the second side of the solid-state lasing material, the harmonic generating crystal material having an input side including a third set of one or more optical coatings that are transmissive to the solid-state wavelength and reflective to a harmonic wavelength of the harmonic generating crystal material and an output side including a fourth set of one or more optical coatings that are reflective to the solid-state wavelength and partially transmissive to the harmonic wavelength.

10. A method for enhancing transverse beam quality of a laser beam, comprising the steps of:

arranging a monolithic and addressable array of surface emitting lasers (SEL) elements adjacent to a solid state lasing material; and

controlling a radial intensity profile of pumping power or emitted wavelength of a combined output of the addressable array of SEL elements into the solid state lasing material by varying an output of one or more concentric rings of SEL elements within the addressable array of SEL elements to control an output power density and an illumination uniformity across the solid state lasing material.

11. A pumped solid-state laser, comprising:

a monolithic and addressable array of surface emitting laser (SEL) elements; and

a solid state lasing material, wherein the addressable array of SEL elements is arranged adjacent to the solid state lasing material, the addressable array of SEL elements including one or more concentric rings of SEL elements, each of the one or more concentric rings of SEL elements having a variable output configured to control a radial intensity profile of pumping power or emitted wavelength of a combined output of the addressable array of SEL elements and thereby controlling an output power density and an illumination uniformity across the solid state lasing material.

12. A method for controlling a direction of beam propagation of a laser beam output by a solid state laser including solid-state lasing material, comprising the steps of:

arranging a monolithic and addressable array of surface emitting laser (SEL) elements adjacent to the solid state lasing material, wherein the array of SEL elements includes one or more sub-regions of SEL elements; and

activating the one or more sub-regions of SEL elements to selectively pump one or more sub-regions of the solid state lasing material and to control the direction of beam propagation of the laser beam.

13. A pumped solid-state laser, comprising:

a monolithic and addressable array of surface emitting laser (SEL) elements; and

a solid-state lasing material, wherein the array of SEL elements is arranged adjacent to the solid-state lasing material, the array of SEL elements including one or more sub-regions of SEL elements, each of the one or more sub-regions of SEL elements selectively activated by a controller to pump one or more sub-regions of the solid-state lasing material to control a direction of beam propagation of one or more laser beams output by the solid-state lasing material.

14. A method for controlling a size or shape of a laser beam output by a solid-state laser, comprising the steps of:

arranging an addressable array of surface emitting laser (SEL) elements adjacent to a solid-state lasing material, wherein the array of SEL elements includes one or more sub-regions of SEL elements; and

activating the one or more sub-regions of SEL elements to selectively pump one or more sub-regions of the solid-state lasing material and to control a size or shape of an optically-active region of the solid-state material so as to control an aperture of the laser beam to the size or shape desired.

15. A pumped solid-state laser, comprising:

a monolithic and addressable array of surface emitting laser (SEL) elements; and

a solid-state lasing material, wherein the array of SEL elements is arranged adjacent to the solid-state lasing material, the array of SEL elements including one or more sub-regions of SEL elements, each of the one or more sub-regions of SEL elements selectively activated by a controller to pump one or more optically-active sub-regions of the solid-state lasing material to control an aperture of one or more laser beams output by the solid-state lasing material to a desired size or shape.