A 593 nm single-frequency orange-yellow pulsed laser based on Ti 3 C 2 T x film passive Q-switching

A passively Q-switched single-frequency orange-yellow pulsed laser at 593 nm is demonstrated using an LD-pumped Nd:YVO 4 crystal to generate simultaneous dual-fundamental waves at 1064 nm and 1342 nm. A Ti 3 C 2 T x film (modulation depth 7.24%) serves as the saturable absorber. Intracavity photon densities are balanced at a 1:1 ratio via a Brewster window, while a Fabry–Pérot etalon enforces single longitudinal mode operation. Sum-frequency generation in an LBO crystal produces 593 nm pulses. At a pump power of 5.8 W, the laser delivers an average power of 50.8 mW at 525.6 kHz, with 36 ns pulse width and 6.55 MHz Lorentzian optical linewidth. Over 4 hours, power instability and RMS noise remain below ±0.41% and 0.32%, respectively. The combination of Brewster window polarization control, F-P etalon mode selection, and Ti 3 C 2 T x film Q-switching provides a feasible route to stable, low-noise single-frequency orange-yellow pulsed emission.