Second harmonic generation in surface periodically-poled lithium niobate waveguides: on the role of multiphoton absorption
Second harmonic generation is investigated in lithium niobate channels realized by proton exchange and quasi-phase-matched by surface periodic-poling. The reduction in conversion efficiency at high powers is interpreted in terms of multi-photon absorption via two-color terms, yielding an estimate of the dominating three-photon process.
physics.optics↗