High-repetition-rate injection-seeded Nd:YVO₄ lasers by high-speed intracavity phase modulation

We demonstrate high-repetition-rate injection-seeded $Q$Q-switched Nd:YVO₄ ring lasers operating at 5 and 10 kHz. The frequency of the lasers is stabilized by the fast ramp-fire technique based on a ${{\rm RbTiOPO}_4}$RbTiOPO₄ intracavity phase modulator. At 5 kHz, the highest output energy of 1.5 mJ is achieved with a pulse duration of 8.1 ns, a frequency jitter of 1.7 MHz/min, and a linewidth of 71 MHz. The corresponding values at 10 kHz are 0.7 mJ, 12.1 ns, 1.9 MHz/min, and 45 MHz, respectively. The short-term timing stability is 15 ns. The performance of the lasers demonstrates that the high-speed ramp-fire technique with the intracavity phase modulator is especially appropriate to obtain stable Fourier-transform-limited single-frequency operation of high-repetition-rate injection-seeded lasers.