Research On Optomechanically Induced Transparency And Second-order Sideband Control In Hybrid Cavity Optomechanical Systems

Cavity optomechanical systems usually consist of optical microcavities coupled to mechanical oscillator by radiation pressure.Benefiting from the continuous progress of nanofabrication technology,the preparation of optical microcavities has also matured,enabling the rapid development of cavity optomechanical in many fields,such as quantum information processing,preparation of non-classical states,ultra-sensitive measurements,and quantum sensor.In recent years,OMIT in cavity optomechanical systems has shown great potential in the field of quantum storage,and several different hybrid cavity optomechanical systems have been proposed,including the PT-symmetric optomechanical system,the Laguerre-Gaussian rotating cavity optomechanical system and the atomic media-assisted optomechanical system.In addition,nonlinear medium can be added to the optomechanical system,providing more ways for quantum manipulation and quantum information processing.Furthermore,as a typical nonlinear phenomenon in optomechanical system,high-order sideband effect is produced by the interaction of four-wave mixing and Raman scattering.Generally,the efficiency of the high-order sideband in the optomechanical system is much lower than the first-order sideband.Therefore,the enhancement of the higher-order sideband effect in the optomechanical system has attracted extensive attention.Firstly,a four-mode hybird cavity optomechanical system containing a Kerr medium is proposed.When the Kerr coefficient is increased,the optomechanical system transitions more easily from the steady state to the unsteady state.When the gain-loss ratio is fixed,increasing the Kerr coefficient will reduce the width of the stable region corresponding to the gain-loss ratio.In addition,compared with the optomechanical system without Kerr medium,it can be found that adding the Kerr medium to the passive cavity results in an increase in the absorption rate of the optomechanical system at the resonance.When the system is in a steady state,the position of the absorption peak can be changed linearly by varying the Kerr coefficient.Furthermore,it is also found that the transition between fast and slow light in the optomechanical system can be achieved by adjusting the Kerr coefficient,the tunneling strength and the amplitude of the pumping field.Then,we also study the high-order sideband effect in the PT symmetric nonlinear cavity optomechanical system.An optical parametric amplifier(OPA)and a Kerr medium are inserted in the passive cavity,and the other cavity is active cavity.When the system is PT-symmetric,changing the tunneling intensity causes the gain in the optomechanical system compensates the losses in the passive cavity,resulting in a significant increase in the second-order sideband efficiency.When the gain of the OPA increases,the number of photons in the passive cavity increases,and the nonlinearity is enhanced,so that the second-order sideband efficiency is significantly enhanced.In addition,the generation efficiency of the second-order sideband can be significantly increased by changing the PT symmetry structure.Furthermore,it is also found that the gain of OPA can effectively control the slow-fast light effect in the optomechanical system.