Compact Q-Switched Oscillator With Combined Nanosecond and Microsecond Pulse Outputs

We have developed a laser-diode side-pumped Qswitched Nd:YAG laser capable of generating combined pulses, consisting of high-peak-power nanosecond (ns) and microsecond (μs) pulses. In free-running mode, a maximum output power of 22.1 W was achieved at a 1 kHz repetition rate with a pulse duration of 115 μs. By carefully adjusting the Q-switch trigger delay and the Q-switch opening time, a combined macro-pulse consisting of a single ns pulse and a μs pulse train was generated, where the ns pulse power ratio relative to the total combined pulse power can be adjusted from 45% to nearly 100%. The peak power of the ns pulse increases from 83 kW to 396.4 kW, while the peak power of the μs pulse decreases from 143.2 W to 87.5 W, corresponding to intensities of up to GW/cm² and MW/cm², respectively. The micro-pulse programmable Q-switched regime is well useful to extend the potential applications of the combined pulse laser, particularly in laser beam drilling.