Side-pumping coupler technology for double-clad fiber

Pumping coupler technology is one of the critical technologies for high-power fiber lasers.The side-pumping coupler technology for double-clad fiber can transfer pumping light into inner cladding through the side of the fiber.It has many advantages over end-pumping technology.There are several kinds of side-pumping structures according to the characteristics of double-clad fiber laser. In the paper,the side-pumping structures,especially which have been adopt in experiments,are introduced.Moreover the characteristics of these technologies are compared.