1.06–0.53 μm second harmonic generation using congruent lithium niobate

Efficient 1.06–0.53 μm second harmonic generation (SHG) has been achieved using congruent lithium niobate. Index inhomogeneities are induced in the lithium niobate, but saturate in the vicinity of the beam thereby allowing efficient SHG to occur. SHG conversion efficiencies of 50% were typically achieved with crystal lengths as short as 9 mm and fundamental power densities of 35 MW/cm2.