Narrow-bandwidth diffraction-limited coupled stable-unstable resonator laser cavity

摘要

A laser cavity providing high power laser radiation with diffraction-limited divergence and narrow-bandwidth comprises: a stable laser cavity including a gain medium, which generates and amplifies laser radiation, optically coupled to first and second reflectors and an optical coupler; and an unstable laser cavity including the gain medium, the first reflector, the optical coupler and a scraper mirror. The scraper mirror is located between the gain medium and the optical coupler for producing an output beam. The stable laser cavity is restricted to operate on a low order TEM mode by an aperture located between the optical coupler and the second reflector. A frequency narrowing element located between the optical coupler and the second reflector narrows the bandwidth of the laser radiation in the stable laser cavity. The optical coupler couples the narrow bandwidth laser radiation from the stable laser cavity to the unstable laser cavity, thereby producing narrow bandwidth laser radiation in the output beam.