Wavelength and position tuning of Cerenkov second-harmonic generation in optical superlattice

We study experimentally the Cerenkov second-harmonic generation in an optical superlattice formed in periodically poled lithium niobate crystal. We demonstrate strong sensitivity of the Cerenkov signal to the wavelength, diameter, and position of the incident fundamental beam. We model the observed behavior by using simple approach based on multiple interference of second harmonic signals emitted from the vicinity of the domain walls. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3659493]