Phase-matched nonlinear optics via patterning layered materials.

The ease of integration and a large second-order nonlinear coefficient of atomically thin layered two-dimensional (2D) materials presents a unique opportunity to realize second-order nonlinearity in a silicon compatible integrated photonic system. However, the phase-matching requirement for second-order nonlinear optical processes makes the nanophotonic design difficult. We show that by nano-patterning the 2D material, quasi-phase-matching can be achieved. Such patterning-based quasi-phase-matching could potentially compensate for inevitable fabrication errors and significantly simplify the design process of the nonlinear nanophotonic devices.