Relaxation oscillation suppressed, narrow linewidth, high beam quality, 1319 nm long-pulsed duration laser

We first report a 1319 nm long-pulsed duration laser with relaxation oscillation suppressed by placing lithium triborate crystals into the laser cavity. Two more etalons were added into the laser cavity to further increase the difference in cavity loss between oscillating and non-oscillating modes. With very little reduction in average output laser power, the smooth temporal profile laser pulse was obtained with a pulse duration of 150 μs. The average output power was 5.45 W, and the beam qualities Mx2 and My2 were 1.12 and 1.20.