Negative Kerr nonlinearity of graphene as seen via chirped-pulse-pumped self-phase modulation

Abstract

We experimentally demonstrate a negative Kerr nonlinearity for quasi-undoped graphene. Hereto, we introduce the method of chirped-pulse-pumped self-phase modulation and apply it to graphene-covered silicon waveguides at telecom wavelengths. The extracted Kerr-nonlinear index for graphene equals n2,gr = -10^(-13) m^2/W. Whereas the sign of n2,gr turns out to be negative in contrast to what has been assumed so far, its magnitude is in correspondence with that observed in earlier experiments. Graphene's negative Kerr nonlinearity strongly impacts how graphene should be exploited for enhancing the nonlinear response of photonic (integrated) devices exhibiting a positive nonlinearity. It also opens up the possibility of using graphene to annihilate unwanted nonlinear effects in such devices, to develop unexplored approaches for establishing Kerr processes, and to extend the scope of the "periodic poling" method often used for second-order nonlinearities towards third-order Kerr processes. Because of the generic nature of the chirped-pulse-pumped self-phase modulation method, it will allow fully characterizing the Kerr nonlinearity of essentially any novel (2D) material.

Cited by in corpus (7)

• Graphene oxide films for ultra-flat optics and linear and nonlinear integrated photonic circuits
• Third-order nonlinear optical response of 2D materials in the telecom band
• Electrically Tunable Optical Nonlinearities in Graphene-Covered SiN Waveguides Characterized by Four-Wave Mixing
• Post-2000 Nonlinear Optical Materials and Measurements: Data Tables and Best Practices
• Enhanced optical Kerr effect method for a detailed characterization of the third order nonlinearity of 2D materials applied to graphene
• Tunable plasmon-enhanced second-order optical nonlinearity in transition metal dichalcogenide nanotriangles
• Third harmonic generation of undoped graphene in Hartree-Fock approximation