Second-Harmonic Generation in Thue-Morse Optical Superlattice

A Thue-Morse optical superlattice made from a single crystal with laminar ferroelectric domain structure was proposed to realize second-harmonic generation. Due to the singular continuous Fourier spectrum in Thue-Morse sequence, this structure shows more plentiful harmonic spectrum, and the intense peaks can be classified according to their different intensity distributions within the superlattice. The harmonic spectra in real space and reciprocal space are presented and discussed.