Optically pumped solid state laser device with self-aligning pump optics

Patent metadata

Field	Value
Publication number	US-9478941-B2
Application number	US-201214395847-A
Country	US
Kind code	B2
Filing date	Nov 15, 2012
Priority date	Apr 26, 2012
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

The present invention relates to an optically pumped solid state laser device, comprising a solid state laser medium ( 300 - 302 ) in a laser resonator. Several pump laser diodes ( 100 ) are arranged to optically pump said solid state laser medium ( 300 - 302 ) by reflection of pump radiation at a mirror element ( 200 ) arranged on the optical axis of the laser resonator. The mirror element ( 200 ) is designed to direct said pump radiation to the solid state laser medium ( 300 - 302 ) and to form at the same time one of the resonator mirrors of the laser resonator. With this design of the solid state laser device an easy alignment of the pump optics is achieved. The proposed solid state laser device can be realized in a compact form.

First claim

The invention claimed is:

1. An optically pumped solid state laser device comprising:
a solid state laser medium in a laser resonator and one or several pump laser diodes, said pump laser diodes being arranged to optically pump said solid state laser medium by reflection of pump radiation at a mirror element,
wherein said mirror element is arranged on an optical axis of said laser resonator and is designed to reflect said pump radiation to the solid state laser medium and to form at the same time a first resonator mirror of the laser resonator, thereby providing a fixed spatial arrangement between the pump radiation and optical axis of the laser resonator,
wherein said mirror element comprises a body of a material optically transparent for laser radiation, said first resonator mirror being formed in a central region of a back surface of the body,
wherein a lens is formed in a central region of a front surface of the body facing the solid state laser medium, said first resonator mirror and said lens being arranged and designed to form a resonator with a second resonator mirror on an opposite side of the solid state laser medium.

2. The device according to claim 1 , wherein said mirror element comprises a central region which forms said first resonator mirror and an outer region which is designed to reflect said pump radiation to the solid state laser medium.

3. The device according to claim 2 , wherein said central region and said outer region are formed with different curvatures.

4. The device according to claim 1 , wherein said first resonator mirror and said lens are arranged to increase a mode size of the laser radiation in the solid state laser medium compared to a resonator of equal length without said lens.

5. The device according to claim 1 , wherein an outer region of the back surface of the body is designed to reflect said pump radiation to the solid state laser medium.

6. The device according to claim 1 , wherein a lens array is formed at the front surface of the body, said lens array being arranged and designed to collimate laser beams of the pump laser diodes propagating towards the back surface of the body.

7. The device according to claim 1 , wherein an outer region of the front surface of the body is designed to reflect said pump radiation to the solid state laser medium.

8. The device according to claim 2 , wherein said pump laser diodes are arranged to emit said pump radiation substantially parallel to the optical axis of the laser resonator towards said mirror element.

9. The device according to claim 2 , wherein said solid state laser medium is mounted in a cooling device or is attached to a cooling device and said pump laser diodes are arranged on a side face of said cooling device being perpendicular to the optical axis of the laser resonator.

10. The device according to claim 7 , wherein said pump laser diodes are arranged to surround an end face of the solid state laser medium at which the pump radiation enters the solid state laser medium.

11. The device according to claim 8 , wherein a body of said mirror element is shaped to mechanically fit with an outer front portion to an outer shape of the cooling device.

12. The device according to claim 2 , wherein said central region of said mirror element is designed to generate a laser mode which does not have a Gaussian intensity profile in the solid state laser medium.

Assignees

• Koninklijke Philips Nv

Inventors

• Gronenborn Stephan

Classifications

• H01S3/09415 Primary

  the pumping beam being parallel to the lasing mode of the pumped medium, e.g. end-pumping · CPC title

• H01S3/09408

  Pump redundancy · CPC title

• H01S3/061

  with elliptical or circular cross-section and elongated shape, e.g. rod · CPC title

• H01S3/0405

  Conductive cooling, e.g. by heat sinks or thermo-electric elements · CPC title

• H01S3/08068 Primary

  Holes; Stepped surface; Special cross-section · CPC title