Abstract

Tunable laser sources in different regions of the optical spectrum are of great interest for a variety of applications in spectroscopy, photochemistry, medical diagnostics, and material processing. Green-pumped optical parametric oscillators (OPOs) are a viable approach for the generation of tunable radiation in the visible and nearinfrared. Such OPOs have been previously demonstrated by exploiting quasi-phase-matched (QPM) nonlinear crystals such as periodically-poled LiNbO₃ (PPLN), stoichiometric LiTaO₃ (PPSLT) and KTiOPO₄ (PPKTP). In particular, PPSLT has proved to be the most viable material for green pumping due to a high photorefractive damage threshold [1,2]. Here we report a green-pumped nanosecond OPO based on periodically-poled Mg-doped congruent LiTaO₃ (PPMCLT), for the first time to our knowledge. Moreover, by using a fan-out grating structure, we demonstrate extended wavelength tuning across a broad range at room temperature.

© 2019 IEEE