Elliptic-mode cavity for diode-pumped lasers

A novel laser resonator capable of producing a strongly elliptic TEM(00) mode in the gain medium is analyzed. Careful design results in an axially symmetric output beam, while the squeezed mode volume in the active medium allows an optimum exploitation of the inversion generated by end pumping the laser with a high-power laser-diode array. When a single array is used, the pump threshold can be typically reduced by an order of magnitude as compared with conventional (circular-mode) end-pumped systems without compromising any other laser characteristics. The combination of the presented cavity design with geometric multiplexing of diode arrays provides an efficient means for scaling end-pumped lasers to high powers.