The resonator includes a lasing medium having a thickness, a first mirror disposed at a first end of the lasing medium and a second mirror disposed at a second end of the lasing medium. The first and second mirror cooperate to fold an intra-cavity laser beam along a plurality of paths through the lasing medium, thereby defining a boundary of a superfluous region within the resonator, wherein the intra-cavity laser beam does not pass through the superfluous region. The first mirror and the second mirror form a laser resonator for a parasitic laser mode, a portion of which is located within the superfluous region. A parasitic mode suppressor is located within the superfluous region of the resonator.