High power, long pulse duration, single-frequency Nd:YVO4 master-oscillator power-amplifier

An efficient single-frequency Nd:YVO4 master-oscillator power-amplifier is described. Gated pulses from a CW diode-pumped ring laser were amplified by three Nd:YVO4 amplifiers. Pulses of 1mJ energy; 2 kW peak power and 1 μs duration were obtained at a repetition frequency of 10 kHz. Analogue shaping of the input pulses was used to control the output pulse shape and thus extend the useful range of pulse widths from the ∼100 ns to the ∼μs regime. A simple mathematical expression was used to model the results which provided reasonable agreement with the experimental work. This system offers a promising pump source for a quasi-CW singly-resonant optical parametric oscillators.