Nonlinear coherent optical responses of tunable optomechanical system based on a bilayer graphene

We have theoretically investigated the nonlinear coherent optical properties of a tunable bilayer graphene with an optical pump-probe technique. The distinct linear/nonlinear optical absorption and the optical Kerr effect have been demonstrated in this tunable bilayer graphene. A feasible way to measure the coupling strength between the electron-hole excitations and the G-mode phonon is proposed with this system. Furthermore, the nonlinear optomechanical properties in this bilayer graphene can be tuned by electrical gating conveniently. The high efficiency and tunability of optical Kerr effects in bilayer graphene predict its potential applications in novel graphene-based optical modulators and switches.