Optical Parametric Amplification in Photonic Chips Integrated with 2D Materials

On-chip integration of two-dimensional (2D) materials provides a promising route for implementing nonlinear integrated photonic devices that break existing barriers and unlock new capabilities. Although 2D materials with ultrahigh optical nonlinearity have driven this technological progress, their high optical absorption also constitutes an Achilles’ heel. Whether 2D materials can overcome their intrinsic absorption and generate net gain (NG) via optical parametric amplification (OPA) processes is a critical and intriguing question, which is central to many nonlinear optical applications. Recently [1], we experimentally demonstrated enhanced OPA and achieved NG in silicon nitride waveguides integrated with 2D graphene oxide (GO) under pulsed pumping. Based on material parameters from this work, this perspective systematically analyzes the feasibility of achieving NG in more widely used, yet more challenging, scenarios involving silicon waveguides incorporating GO and continuous-wave pumping. The results show that a gap still exists toward achieving this goal, but it can be bridged through combined efforts in optimizing waveguide structure, reducing loss of GO, and improving GO’s thermal stability. We also investigate different waveguide structures as well as other 2D materials, and analyze the gap in each case. This work provides a critical roadmap and useful guidance for future developments towards achieving NG via OPA in integrated photonic devices incorporating 2D materials.