Optical fiber laser

Abstract

To provide a low-cost, high reliability and high-powered operation enabled optical fiber laser, in the optical fiber laser for oscillating a laser light by introducing an excitation light for exciting the rare earth elements into the optical fiber doped partially by the rare earth elements, the optical fiber is wrapped around the base member, and one part of the outer circumferential area of the wrapped optical fiber is processed in order to form a flat surface, and one face of the prism is made contacted to the flat surface, and the excitation light is introduced to another surface of the prism.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a structural diagram of the optical fiber laser illustrating one embodiment of the present invention shown as a cross section view projected onto the plane orthogonal to the primary axis of the base member.

FIG. 1B is a magnified partial picture of the cross section view shown by FIG. 1A.

FIG. 1C is a magnified partial picture of the cross section view of the part projected onto the plane parallel to the primary axis of the base member.

FIG. 2A is a magnified partial picture of the cross section view of the base member projected onto the plane parallel to the primary axis of the base member in another embodiment of the present invention.

FIG. 2B is a magnified and partial picture of the cross section view of the base member projected onto the plane parallel to the primary axis of the base member in another embodiment of the present invention.

FIG. 3 is a cross section view of the photonic band gap fiber used in another embodiment of the present invention.

FIG. 4 is a schematic view of the double-dad type optical fiber used in one embodiment of the present invention.

FIG. 5A is a structural diagram of the excitation method for the optical fiber laser in the prior art.

FIG. 5B is another structural diagram of the excitation method for the optical fiber laser in the prior art.

FIG. 5C is another structural diagram of the excitation method for the optical fiber laser in the prior art.

FIG. 6 is a structural diagram of the optical fiber laser in the prior art.

Claims

1. An optical fiber laser for oscillating a laser light by introducing an excitation light for exciting a rare earth element, comprising: an optical fiber doped partially by the rare earth element and wrapped around a base member, one part of an outer circumferential area of said wrapped optical fiber being processed in order to form a flat surface; anda prism, whose one face is made contacted to the flat surface;wherein the excitation light is introduced into said optical fiber through another surface of said prism.

2. The optical fiber laser according to claim 1, wherein one face of the prism is contacted to one face of the flat surface, and a metal film for reflecting the excitation light is coated on the exposed flat surface without contacting to the prism.

3. The optical fiber laser according to claim 1, wherein the optical fiber is composed of a solid core region, inner and outer cladding regions concentric to the solid core region, the rare earth element is doped to the solid core region, a refractive index of the inner cladding region is made smaller than that of the solid core region and larger than that of the outer cladding region, and the flat surface is formed so as to reach the inner cladding region.

4. The optical fiber laser according to claim 1, wherein the optical fiber is composed of a hollow core region, inner and outer cladding regions concentric to the hollow core region, plural holes are formed in the inner cladding region in order to form a photonic band gap in an oscillation light wavelength band, the rare earth element is doped to the solid part of the inner cladding region, a refractive index of the outer cladding region is made smaller than that of the solid part of the inner cladding region, and the flat surface is formed so as to reach the inner cladding region.

5. The optical fiber laser according to claim 1, wherein a mirror surface is formed at an outer circumferential area of the base member.

6. The optical fiber laser according to claim 1, wherein a groove for supporting the optical fiber is formed at an outer circumferential area of the base member.

7. The optical fiber laser according to claim 1, wherein the wrapped optical fiber is fixed by transparent adhesive material having a refractive index smaller than that of the outer cladding region.

8. The optical fiber laser according to claim 1, wherein the excitation light source is configured in a bar structure in which a light emitting device part is arranged in a linear array or configured in a stack structure in which linear arrays are piled.

9. The optical fiber laser according to claim 1, wherein an outer surface of the base member is formed with a smooth, flat surface and a curved surface.

10. The optical fiber laser according to claim 1, wherein the excitation light is introduced respectively into a couple of surfaces of the prism, in which those surfaces do not contact to the flat surface of the circumferential area of the optical fiber.