Patent ID: 8953648
Filing Date: 2015-02-10
Classification: H01S

Abstract:
1. An apparatus for free space pumping of active double-clad fiber based lasers and amplifiers, said apparatus comprising: a laser that emits a signal laser beam; an active double-clad fiber having a core that defines an optical axis of said apparatus and a pump cladding that defines a cone of numerical aperture (NA); a laser optical arrangement adapted to direct said signal laser beam along said optical axis through an end facet into the core of said active double-clad fiber; at least one pump source, each of which emits a pump beam; at least one delivery means adapted to couple said pump beam to the pump cladding of said active double-clad fiber; and an optical arrangement to couple an amplified signal laser beam that exits said active double-clad fiber out of said apparatus; wherein, a separate one of said delivery means is used to couple each of said pump beams to said pump cladding of said active double-clad fiber from a separate direction but at a same off-axis angle with respect to said optical axis of said apparatus; and wherein, each of said pump beams is directly coupled to said pump cladding through the end facet of said active double-clad fiber.