Face-pumped laser with diffraction-limited output beam

摘要

Diffraction-limited output beam quality is achieved with a laser having an elongated homogeneous active medium pumped through two optically plane, parallel faces and situated within a resonant cavity defined by a plane reflector at one end and a concave spherical reflector at the opposite end. For a ray of optical energy passing through the active medium, there is a plane containing the ray in which the effective optical length in the medium is greater than the effective optical length in the orthogonal plane containing the ray. The separation between the cavity reflectors is selected to form a stable resonator in one of these planes and an unstable resonator in the orthogonal plane.