Modulation and Enhancement of Optical Nonlinearity in2DMaterials

Atomically thin van der Waals two-dimensional (2D) materials provide the opportunities to realize on-chip integration of nonlinear optical devices. Although nonlinear susceptibility of 2D materials is large, the short light–matter interaction limits the efficiency of nonlinear optical process. In addition, practical application requires the nonlinear response that can be actively tuned. In this chapter, the main strategies to enhance and manipulate the optical nonlinearity of 2D materials will be introduced, including structural engineering, optical manipulation, electrical manipulation, and magnetic manipulation.