Novel High-power Nd:YAG-MISER

MISERs (Monolithic Isolated Single-mode End- pumped Ring lasers) represent the most stable class of single-frequency laser sources currently available. These lasers are traveling wave ring oscillators with an intrinsic optical diode.1 Spatial hole-burning and the resulting longitudinal multi-mode oscillation are therefore suppressed. The monolithic design provides very high frequency stability. These unique properties lead to a broad area of applications, e.g., free space communication, pumping of cw-OPOs or gravitational wave detection. However, for many applications the currently available output power of 1-2 W is not sufficient. Power scaling of these conventional MISERs is limited by pump light induced thermooptical aberrations and stress-induced birefringence within the Nd:YAG crystal. Especially the thermal lens leads to the appearance of higher-order transverse modes.