Patent ID: 8320039
Filing Date: 2012-11-27
Classification: H01S

Abstract:
1. An optical amplifier comprising at least two gain regions, an intermediate region situated between the gain regions, and a transition region situated between the intermediate region and each gain region, wherein: (a) the gain regions, the transition regions, and the intermediate region have claddings that collectively form a path for pump radiation propagating from at least one of the gain regions to the other gain region; (b) the gain regions, the transition regions, and the intermediate region have cores that collectively form a path for signal radiation propagating from at least one of the gain regions to the other gain region; (c) the gain region cores support a plurality of propagating optical modes at least at some wavelengths present during operation of the amplifier, said propagating core modes including at least one signal mode and at least one non-signal mode; (d) the intermediate region supports fewer propagating core modes than the gain regions; and (e) the transition regions are conformed to couple at least some radiation out of propagating non-signal core modes of the gain regions, and into the cladding of the intermediate region; and (f) the cladding-formed pump radiation path is optically continuous.