Abstract: A fiber coupling device includes a housing and a window provided in the housing. The fiber coupling device is configured to collectively guide plural laser beams to at least a first fiber, the plurality of laser beams each being emitted from a corresponding one of plural external laser light sources and entering through a laser beam inlet. The housing is configured such that the laser beams enter the housing from the laser beam inlet. The window is provided inside the housing and faces the laser beam inlet. The fiber coupling device is not required to detach when an optical axis is adjusted.

Abstract: The fiber component of the present invention has a fusion splice section for connecting optical fibers. The optical fiber as the receiver of transmitted light is coated with at least two-layer resin. In the vicinity of the fusion splice section for connecting optical fibers, the innermost layer of a resin-coat section is uncovered with other resin coat at the boundary between the resin-coat section and resin-coat removed section of the optical fiber coated with two-layer resin. The structure effectively releases light and suppresses increase in temperature of the resin-coat section, protecting the optical fibers from burn-out.

Abstract: The fiber component of the present invention has a fusion splice section for connecting optical fibers. The optical fiber as the receiver of transmitted light is coated with at least two-layer resin. In the vicinity of the fusion splice section for connecting optical fibers, the innermost layer of a resin-coat section is uncovered with other resin coat at the boundary between the resin-coat section and resin-coat removed section of the optical fiber coated with two-layer resin. The structure effectively releases light and suppresses increase in temperature of the resin-coat section, protecting the optical fibers from burn-out.

Abstract: A fiber laser apparatus includes an optical amplification fiber with a multi-core structure composed of a first waveguide that pumping light enters and that transmits the pumping light; a second waveguide composed of a core containing a laser medium and for generating laser, and a clad for transmitting pumping light; and a third waveguide containing the first waveguide and the second waveguide. The optical amplification fiber is wound while the curvature radius is being changed to provide a small-size, high-power fiber laser apparatus.

Abstract: A fiber laser apparatus includes an optical amplification fiber with a multi-core structure composed of a first waveguide that pumping light enters and that transmits the pumping light; a second waveguide composed of a core containing a laser medium and for generating laser, and a clad for transmitting pumping light; and a third waveguide containing the first waveguide and the second waveguide. The optical amplification fiber is wound while the curvature radius is being changed to provide a small-size, high-power fiber laser apparatus.

Abstract: A small size and high efficiency laser oscillation apparatus capable of obtaining high output and high beam quality laser light is provided. First waveguide (21) (refractive index=n1) for transmitting excitation light, second waveguide (22) composed of core (23) (refractive index=n3) for generating laser light and clad (24) (refractive index=n2) for transmitting the excitation light, and third waveguide (25) (refractive index=n4) including first waveguide 21 and second waveguide 22 are provided. Light amplifying fiber (20), in which the refractive indices are set so as to satisfy the relation: n1<n4<n2<n3, is used and excised by semiconductor lasers (10a) and (10b).

Abstract: A small size and high efficiency laser oscillation apparatus capable of obtaining high output and high beam quality laser light is provided. First waveguide (21) (refractive index=n1) for transmitting excitation light, second waveguide (22) composed of core (23) (refractive index=n3) for generating laser light and clad (24) (refractive index=n2) for transmitting the excitation light, and third waveguide (25) (refractive index=n4) including first waveguide 21 and second waveguide 22 are provided. Light amplifying fiber (20), in which the refractive indices are set so as to satisfy the relation: n1<n4<n2<n3, is used and excised by semiconductor lasers (10a) and (10b).