HIGH POWER OPTICAL APPARATUS EMPLOYING LARGE-MODE-AREA, MULTIMODE, GAIN-PRODUCING OPTICAL FIBERS

摘要

PROBLEM TO BE SOLVED: To provide a multimode GPF that is core-pumped with a high brightness pump source.;SOLUTION: An optical apparatus includes a multimode, gain-producing fiber for providing gain to signal light propagating in the core of the fiber, and a pump source for providing pump light that is absorbed in the core, and is characterized in that (i) the pump source illustratively comprises a low brightness array of laser diodes and a converter for increasing the brightness of the pump light, (ii) the pump light is coupled directly into the core, and (iii) the area of the core exceeds approximately 350 μm². In one embodiment, the signal light propagates in a single mode, and the pump light co-propagates in at least the same single mode, both in a standard input fiber before entering the gain-producing fiber, and a mode expander is disposed between the input fiber and the gain-producing fiber. In another embodiment, multiple pumps are coupled into the core of the gain-producing fiber. The pumps may generate light of the same wavelength or of different wavelengths.;COPYRIGHT: (C)2014,JPO&INPIT