Cladding-pumped optical fiber gain devices

摘要

An optical gain device comprises an input optical fiber (21), an optical fiber adiabatic transformer section comprising a GRIN optical fiber (26) coupled to the input optical fiber (21), an optical fiber gain section (28), coupled to the optical fiber adiabatic transformer section, and means for optically pumping the gain section, wherein the GRIN optical fiber has a refractive index that is graded so that a light beam passing through the GRIN optical fiber (26) has a modefield that expands from the input optical fiber (21) to the optical fiber gain section (28).