Enhanced optomechanically induced transparency and slow/fast light in a position-dependent mass optomechanics

We impart a theoretical method to enhance optomechanically induced transparency (OMIT) and slow/fast light in a standard optomechanical system composed of a fixed mirror and a moving end mirror. The system is driven by a strong pump field and probed by a weak probe field, respectively. We consider the mass of the mechanical resonator is position-dependent which generates a nonlinear effect in the system. In this paper, we show that the nonlinear parameter alpha of the position-dependent mass shifts the system from Stokes to the anti-Stokes regime, as a result, OMIT of the transmission field enhances. Further, we show the nonlinear parameter alpha changes the transparency window from symmetric to asymmetric window profile and looks like Fano resonances. Moreover, in the presence of alpha, we explain the behavior of mirror field coupling on the width of the transparency window as well. In particular, we present the enhancement of slow/fast light corresponds to the positive/negative dispersion of the phase associated with the transmission probe field.