Yellow–green–blue triple-wavelength laser for an oceanic lidar: optimizing penetration depth from inshore to open ocean water

We have demonstrated a yellow-green-blue triple-wavelength pulsed laser based on a parallel frequency-doubled optical parametric oscillator. Pumped by a 532.2 nm pulsed laser, the potassium titanyl phosphate crystal-based optical parametric oscillator generated a signal laser at 972 nm and an idler laser at 1176 nm. After two parallel second harmonic generators, the signal laser and the idler laser were simultaneously frequency-doubled to a 486 nm blue laser and a 588 nm yellow laser, corresponding to the optimal penetration wavelengths for open ocean and inshore water, respectively. The maximum single pulse energy and pulse width of the blue laser were 14.93 mJ and 5.12 ns, and the maximum single pulse energy and pulse width of the yellow laser were 10.75 mJ and 3.18 ns. In addition, the pulse energy and pulse width of the green laser were 65.8 mJ and 5.28 ns. This triple-wavelength pulsed laser has the potential to be used to enhance the penetration depth of oceanic lidar from inshore to open ocean water.