QUASI-PHASE-MATCHED 2ND-HARMONIC GENERATION OF BLUE-LIGHT IN PERIODICALLY POLED LINBO3

LiNbO3 crystals with periodically alternating ferroelectric domains have been produced using laser-heated pedestal growth. Domain thicknesses as small as 1 μm have been achieved. This material was applied to room-temperature, quasi-phase-matched frequency doubling to generate light at wavelengths as short as 407 nm, using the d33 and d 22 nonlinear coefficients. The measured conversion efficiencies and wavelength and temperature tuning bandwidths are consistent with an effective interaction length of ≊320 μm (>230 domains). An initial test with high-intensity focused blue beams showed that the periodically poled material exhibits no discernible photorefractive damage effect.