Hybrid integration of 2D materials for on-chip nonlinear photonics

Interests surrounding the development of on-chip nonlinear optical devices have been consistently growing in the past decades due to the tremendous applications, such as quantum photonics, all-optical communications, optical computing, on-chip metrology, and sensing. Developing efficient on-chip nonlinear optical devices to meet the requirements of those applications brings the need for new directions to improve the existing photonic approaches. Recent research has directed the field of on-chip nonlinear optics toward the hybrid integration of two-dimensional layered materials (such as graphene, transition metal dichalcogenides, and black phosphorous) with various integrated platforms. The combination of well-known photonic chip design platforms (e.g., silicon, silicon nitride) and different two-dimensional layered materials has opened the road for more versatile and efficient structures and devices, which has the great potential to unlock numerous new possibilities. This review discusses the modeling and characterization of different hybrid photonic integration structures with two-dimensional materials, highlights the current state of the art examples, and presents an outlook for future prospects.