The design, construction, and characterization of a diode-pumped SESAM mode-locked TE M 00 Nd:YV O 4 green laser were reported. Based on the simulation results, the technical route for the construction and optimization of the resonator was determined. A KTP was used as the intracavity frequency doubling crystal. The maximum output average power at 532 nm was 500 mW with a repetition rate of 82 MHz at a pump power of 5 W. In addition, the measured and simulated beam quality was about M 2 < 1.4 , indicating the single-mode operation of the laser. Moreover, the spectral characteristics of the laser at 1064 nm and 532 nm were analyzed. The time duration of the pulses at 1064 nm was about 9.4 ps. The theoretical calculations based on the time-bandwidth product evaluation method predicted the time duration of 6.6 ps for the pulses at 532 nm.

This study presents a compact intracavity difference-frequency generation (DFG) source designed for mid-infrared (mid-IR) applications. By optimizing overlap between the pump and signal beams, we obtained a black-box efficiency (${\eta }_{BB}$) of 3.4% W⁻¹ and a maximum DFG output power of 63 mW at a wavelength of 3437 nm for a 50 mm long periodically poled lithium niobate (PPLN) crystal. The mid-IR laser was systematically studied for various PPLN lengths (29 mm, 40 mm, and 50 mm), demonstrating extensive tunability across a range of mid-IR wavelengths. Stability assessments over short-term (2 min) and long-term (2 h) periods were also investigated, showing stability values of 0.91% and 1.08%, respectively. These advancements position our DFG laser as a promising candidate for potential applications in greenhouse gas detection and satellite communication, addressing the growing demand for reliable and efficient mid-IR sources.