Nd:YVO4 amplifier for ultrafast low-power lasers

An Nd:YVO4 amplifier consisting of two modules end-pumped at 808 nm at 30-W total absorbed power has been designed for efficient, diffraction-limited amplification of ultrafast pulses from low-power seeders. We investigated amplification with a 50-mW, 7-ps Nd:YVO4 oscillator, a 2-mW, 15-ps Yb-fiber laser, and a 30-mW, 300-fs Nd:glass laser. Output power as high as 9.5 W with 8-ps pulses was achieved with the 250-MHz vanadate seeder, whereas the 20-MHz fiber laser was amplified to 6 W. The femtosecond seeder allowed extracting Fourier-limited 4-ps pulses at 7-W output power. To our knowledge, these are the shortest pulses from any Nd:YVO4 laser device with at least 7 W output power. This suggests a novel approach to exploit the gain bandwidth of vanadate amplifiers with high output power levels. Such amplifier technology promises to offer an interesting alternative to high-power thin-disk oscillators at few picoseconds duration, as well as to regenerative amplifiers with low-repetition-rates fiber seeders.