Laser resonator with parasitic mode suppression

A resonator for a laser comprising:

• a first resonator wall;
• a second resonator wall that is separated from the first resonator wall in a transverse direction thereby defining a gap between the first and second resonator walls;
• a lasing medium disposed in the gap;
• a first mirror disposed at a first end of the first and second resonator walls;
• a second mirror disposed at a second end of the first and second resonator walls,
• wherein the first and second mirror cooperate to fold an intra-cavity laser beam along a plurality of paths through the lasing medium,
• wherein the plurality of paths define a boundary of a superfluous region within the resonator, wherein the intra-cavity laser beam does not pass through the superfluous region;
• wherein the first mirror and the second mirror forms a laser resonator for a parasitic laser mode, a portion of which is located within the superfluous region;
• a parasitic mode suppressor that is located within the superfluous region of the resonator and is disposed between the first end of the first resonator wall and the first mirror.