Frequency stability and offset locking of a laser-diode-pumped Nd:YAG monolithic nonplanar ring oscillator

The frequency stability of laser-diode-pumped, monolithic Nd:YAG solid-state unidirectional nonplanar ring oscillators was studied by heterodyne measurements. We obtained cw single-axial- and transverse-mode power of 25 mW at 1064 nm at a slope efficiency of 19%. Two independent oscillators were offset locked at 17 MHz with frequency fluctuations of less than +/-40 kHz for periods of 8 min.