Optical fiber lasers and amplifiers.

摘要

Apparatus for coupling radiation into a single-mode core of an optical fiber laser has a single-mode core (100) disposed within a relatively large, multimode cladding (210) at a location which is displaced from the center of the cross-section of the cladding. The cladding is surrounded by a further layer (120) to prevent radiation from propagating out of the cladding. In addition, the apparatus preferably has slight bends to enhance the coupling of radiation from the cladding into the single-mode core. A further embodiment has a single-mode fiber laser (200) disposed in a relatively large, multimode, slab cladding (210) which, in turn, is surrounded by another cladding (220) to prevent radiation from propagating out of the large cladding.