Transient frequency shift in a single-mode quasi-continuous diode-pumped Nd: YAG laser

The transient frequency shift of a quasi-continuous single-mode frequency-d oubled diode-pumped Nd:YAG ring laser has been measured using a confocal sp herical Fabry-Perot. At a rate of 50 Hz, a quasi-linear shift of 5.4 MHz at the fundamental 1.06-mum wavelength has been measured during the 150-mus l aser pulse duration. The doubled frequency, which is obtained by an intraca vity LBO crystal, shows also a similar but doubled linear shift. This obser ved frequency shift is interpreted as due to thermal effects in the rod and fits well a modeling of the pulsed laser diode pumping. Introducing intrac avity compensation, a piezoceramic transducer mounted cavity mirror, has li mited the observed shift to less than +/-1 MHz, Such a quasi-continuous Nd: YAG single-mode and frequency stabilized device should be a very suitable s ingle-mode laser source to pump optical parametric oscillator systems.