A dual-port broadband light source is disclosed. In the dual-port broadband light source, a first beam splitter splits a first ASE at a first ratio into the second and third light paths and outputs the first ASE received from the second light path to the first light path. A second beam splitter splits a second ASE at a second ratio into the second and fourth light sources and outputs the second ASE received from the second light path to the first light path. A first reflector reflects input first and second ASEs in the first light path, and a second reflector reflects input first and second ASEs in the second light path. A first gain medium generates the first ASE between the first reflector and the first beam splitter, and a second gain medium generates the second ASE between the first reflector and the second beam splitter.