Second harmonic generation in microdomain gratings fabricated in strontium-barium niobate crystals with an atomic force microscope

摘要

Regular surface domain gratings were created in strontium barium niobate crystals by local poling with an AFM-tip. Piezoresponse force microscopy was utilized to subsequently image the domain patterns and to investigate their temporal and thermal stability. The gratings were examined by means of nonlinear diffraction in reflection geometry using a Ti-sapphire laser (800 nm) as pump source. The well-resolved second harmonic diffraction patterns were recorded for various angles of incidence of the fundamental wave. The origin of the observed nonlinear diffraction is discussed.