Patent ID: 7457327

Claim:
A fiber laser oscillator comprising: a rod-shaped optical fiber having a longitudinal axis and including a rod-shaped core portion and a cladding portion covering the circumference of the core portion, wherein the core portion contains laser activation material and wherein the cladding portion has a refractive index smaller than a refractive index of the core portion; a pumping light emitting device arranged and constructed to emit a pumping light, wherein the pumping light diverges in both a major axis direction and a minor axis direction as the pumping light travels from the pumping light emitting device; a light guide member having an integral cylindrical entrance surface constructed to receive the pumping light and constructed to direct the pumping light along a longitudinal axis into the light guide member, said light guide member arranged and constructed to provide a guide for the pumping light emitted from the pumping light emitting device; and a core member arranged and constructed to receive the pumping light under the guidance of the light guide member and to confine the pumping light therein, said light guide member disposed on an outer side of the core member; wherein the core member is configured to have a cylindrical, annular, or a hollow spherical configuration; wherein the optical fiber is positioned such that at least a part of the optical fiber is embedded within the core member or such that the optical fiber is wound around a surface of the core member; wherein the light guide member has a pumping light receiving surface positioned adjacent to the pumping light emitting device, so that the pumping light emitted from the pumping light emitting device is guided within the light guide member; wherein the light guide member has an opposite surface positioned opposite to the pumping light receiving surface and defining a contact surface contacting the circumference of a mating surface of the core member, wherein the light guide member is positioned relative to the core member such that the pumping light outgoing from the light guide member is inclined by a first predetermined angle relative to a plane tangential to the mating surface of the circumference of the core member to which the contact surface of the light guide member contacts, so that the pumping light guided within the light guide member enters the core member via the opposite surface contacting with the core member and circulates along the circumference of the core member.