We report on a high-repetition-rate, high-power continuously pumped Nd:GdVO₄ regenerative amplifier. Numerical simulations successfully pinpoint the optimum working point free of bifurcation instability with simultaneous efficient energy extraction. At a repetition rate of 100 kHz, a maximum output power of 23 W was obtained with a pulse duration of 27 ps, corresponding to a pulse energy of $230~\unicode[STIX]{x03BC}\text{J}$. The system displayed an outstanding stability with a root mean square power noise as low as 0.3%. The geometry of the optical resonator and the pumping scheme enhanced output power in the $\text{TEM}_{00}$ mode with a single bulk crystal. Accordingly, nearly diffraction-limited beam quality was produced with $M^{2}\approx 1.2$ at full pump power.

1.2 μJ pulses with average power of 9 W were directly generated from a passively mode-locked picosecond oscillator based on a Nd:GdVO4 bulk crystal. Short cavity operation in continuous wave and mode-locking regimes was conducted first to confirm the resonator performance and proper alignment. With a carefully calibrated q-preserving multi-pass cell inserted into the laser cavity, the cavity length of the original short cavity was extended while the mode-matching condition was maintained fairly well. Compared with the short cavity, nearly fivefold energy enhancement was achieved while the diffraction-limited beam quality was undisturbed. To the best of our knowledge, this is the highest output power ever produced from a mode-locked oscillator based on a single bulk crystal at a repetition rate below 10 MHz without cavity dumping.

The laser performance of a new Yb:germanophosphate (Yb:GP) glass is investigated. A maximum output power of 826 mW at 1063 nm is achieved with direct diode pumping at 976 nm. The wavelength is tuned from 1034.47 to 1070.83 nm, corresponding to a tuning range of 36.36 nm. Thermal lens effects are investigated to optimize the optical cavity.