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 α 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 α changes the transparency window from symmetric to asymmetric window profile and looks like Fano resonances. Moreover, in the presence of α , 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. Graphical abstract