Abstract

A self-filtering unstable resonator (SFUR) is a negative-branch confocal unstable resonator in which the field-limiting aperture, set at the common focal plane of the mirrors, acts as a filter to shape a very smooth spatial beam profile and to cool the hot focal point inside the cavity down to nondamage limits. In Refs. 1 and 2 we demonstrated both theoretically and experimentally that this kind of resonator is highly effective in producing large-volume smooth-profiled beams with an increase in oscillator efficiency and excellent energy transport and focusabillty.

© 1985 Optical Society of America