A laser system having a cooling apparatus is disclosed. The laser system includes a resonator, a gain medium and multiple heat-absorbing discs. The resonator is formed by a first mirror and a second mirror. The gain medium, which is contained within the resonator, is collectively formed by a group of gain medium segments. Each of the gain medium segments is preferably in the shape of a cylindrical disc. The heat-absorbing discs are interleavely disposed among the gain medium segments to provide face cooling for the gain medium segments during the operation of the laser system.