Abstract: A laser resonant cavity defined by a set of reflective end elements positioned to together form a closed optical path, again medium positioned along the closed optical path, means for exciting the gain medium to produce a laser beam within the cavity, at least one focusing element positioned within the cavity in optical alignment with the gain medium, and a prism positioned as one of the end elements of the cavity and providing angular dispersion of the laser beam. The prism, end elements, gain medium, and focusing elements are positioned with respect to each other such that the resonant cavity supports a coexistence of several monochromatic laser modes, each mode having a distinct propagation axis. Propagation axes of modes having relatively longer wavelengths traverse more of the prism than propagation axes of modes having relatively shorter wavelengths, resulting in the addition of a negative component to the group velocity dispersion of the laser cavity.