Single-frequency, TEM/sub 00/-mode Nd:YLF laser with image-rotation resonator

Summary form only given. Transverse-mode selection techniques for different resonators have in common that they generally restrict the area of the gain medium to discriminate against higher-order modes. For stable spherical resonators with g<1, the selection techniques (e.g., including a restrictive aperture in the cavity or matching the TEM/sub 00/ mode size to the pump size) rely on the fact that the higher-order modes cover a larger cross-section area than the fundamental mode. Restricting the active area to the size of the TEM/sub 00/ mode generally introduces only small diffraction losses for the fundamental mode but substantially limits achievable output powers. We demonstrate a new concept of transverse mode selection in plane or near-plane resonators, which makes them competitive with spherical resonators. The concept is based on using image rotation, which essentially decreases the sensitivity to cavity distortions and increases the azimuthal homogeneity of both the gain and refractive index of the laser medium.