Engineering of a dual-periodic optical superlattice used in a coupled optical parametric interaction

Quasi-phase matching facilitates the phase matching of any parametric interaction by setting an appropriately modulated period. We propose a dual-periodic structure that is used in the construction of a frequency-conversion device. For example, we have designed and fabricated such a dual-periodic structure in a LiTaO3 crystal. Using a fundamental source at 1.064 µm, we obtained ultraviolet radiation at 355 nm and green radiation at 532 nm simultaneously by frequency tripling and frequency doubling the fundamental source. Theoretically, this idea can be further extended to the design of a multiperiodic structure for achievement of more quasi-phase-matched processes in a single optical superlattice.