Widely tunable and narrow-bandwidth pulsed mid-IR PPMgLN-OPO by self-seeding dual etalon-coupled cavities

Integrating narrow-bandwidth and wavelength tunability together is crucially important in upgrading the applications of optical parametric oscillators (OPO). Here, we have demonstrated a widely tunable, narrow-bandwidth and efficient mid-IR OPO pumped by a single-longitudinal-mode pulsed Yb-fiber laser. By restricting the bandwidth of the oscillated signal via self-seeding dual etalon-coupled cavities, the bandwidth of the idler can be suppressed to about 0.35 nm, with a wide tunable range of 2.85-3.05 μm, which can be achieved by synergistically adjusting the temperatures of PPMgLN crystal and one of the etalons. The maximum idler power at 3.031 μm is 2.67 W with an optical-to-optical conversion efficiency of 17.4%.