Periodically poled lithium niobate monolithic nanosecond optical parametric oscillators and generators.

We fabricated and characterized periodically poled lithium niobate monolithic optical parametric oscillators (OPO's) and generators. The compact monolithic devices were trivial to align and operate and provided widely tunable, nearly diffraction-limited, stable output pulses. Low thresholds and high conversion efficiencies were obtained when the devices were pumped with 3.5-ns 1.064-mum pulses. In addition, the monolithic OPO devices exhibited broad tuning by crystal rotation through noncollinear phase matching. The bandwidth-broadening effects exhibited in the noncollinear phase-matching geometry were measured and explained.

Diffusion-bonded stacks of periodically poled lithium niobate.

We constructed diffusion-bonded stacks of periodically poled lithium niobate (PPLN). Such crystals combine the advantages of planar processing used to make PPLN wafers with the power-handling capability of large apertures. We demonstrated an optical parametric oscillator that uses a 3-mm-thick diffusion-bonded stack consisting of three 1-mm-thick PPLN crystals.