Multiwavelength diode array end-pumped, thermally stabilized, Nd:YAG pulsed laser

An electro-optic Q-switched multiwavelength laser diode array end-pumped Nd:YAG laser without temperature control is proposed and demonstrated in this paper. Using a 3.2 kW multiwavelength laser diode array as the pump source, a lens duct as the coupling system, RTP crystals as the Q-switch, and an end-pumped Nd:YAG crystal rod (Ø 6 × 60 mm2) as the gain medium, the laser system obtained a maximum output pulse energy of 72 mJ at room temperature with a pulse width of 15.8 ns, a repetition rate of 20 Hz, and an optic-optic conversion efficiency of 11.25%. Meanwhile, the output energy increased from 69 mJ at −40 °C to 78 mJ at 60 °C, with an energy instability of less than 10% and a pulse width instability of less than 15% over the full temperature range of 100 °C. The divergence angles of the output laser in the horizontal and vertical directions were measured as 2.5 and 2.6 mrad, respectively. The work the authors have done will provide important references for other researchers to carry out similar research studies.