Optomechanically induced transparency and gain

Optomechanically induced transparency is an important quantum phenomenon in cavity optomechanics. Here, we study the properties of optomechanically induced transparency in the simplest optomechanical system (consisting of one cavity and one mechanical resonator) considering a nonlinear effect that was ignored in previous works. With the nonlinear effect, we find the ideal optomechanically induced transparency dip can be easily achieved, and the width of the optomechanically induced transparency dip can become very narrow especially in the unresolved sideband regime. Finally, we study the properties of optomechanically induced gain, and give the analytic expression about the maximum value of gain.