Disclosed is an annular-beam coupling system enabling reduction of noise generated from a core of a double-clad fiber. The disclosed annular-beam coupling system comprises: a fiber for transmitting light of a light source; a collimator for receiving the light outputted from the fiber and forming a parallel beam of a circular shape; an annular-beam generation unit for converting the parallel beam into an annular beam; and a double-clad fiber having the annular beam coupled to a cladding region thereof.