Investigations On Nonlinear Phenomena Of Optomechanical System Coupled With A Quantum Dot

In recent years,the optomechanical system has attracted widespread attention and great interest.As the size of nanomechanical vibrators can reach micron and nanometer scales,optomechanical system play an increasingly important role in high-precision measurement such as displacement measurement and mass detection.By confining the quantum dots in a cavity,and constantly interacting with the photons trapped in the cavity,the interaction is stronger than the loss to achieve strong coupling between the cavity and the quantum dots,so that quantum process of quantum dot-cavity systems can be effectively manipulated.The implementation of quantum dots embedded in semiconductor optical microcavities during the growth process provides a new platform for studying the interaction of light and matter.In this thesis,the properties of optical bistable and transmission field spectra in quantum dot and optomechanical hybrid systems are studied.The main works are as follows:(1)Firstly,the development of cavity optomechanical,principles and several typical cavity light systems are introduced in detail.Then introduced the field of nonlinear optics application and development process andseveral nonlinear quantum optical effects at microscopic scale,as well as the main properties,application fields and preparation methods of quantum dots.(2)A brief introduction to the three commonly used scenes in quantum mechanics,the simplest model of light-material interaction(J-C model),quantum Langevin equation and optical bistable basic theory and tools.(3)The optical bistable in a quantum dot-cavity optomechanical hybrid system containing high-density excitons in quantum dots is studied.The amount of detuning and the effect of driving the light field frequency on the bistable state are discussed in detail.It turns out that the system exhibits an optical bistable state that is different from normal due to the combination of optomechanical coupling and exciton-exciton scattering.This non-classical property can be controlled by pumping the power and frequency of the laser.The most interesting thing is that there is a close relationship between the number of excitons and the average number of photons in the cavity.When the exciton number appears bistable,the average photon number in the cavity exhibits bistable state at the same time;when the average number of photons in the cavity is not When the bistable condition is satisfied,the bistable state of the exciton number also disappears,and the bistable parameter range of the average photon number in the cavity is almost the same as that of the excitons.We have derived the conditions for bistable under exciton-exciton scattering.(4)In this system,we also discuss in detail the physical phenomena of the transmission field spectrum and all the peaks appearing in the spectrum,which proves that the transmission field spectrum is composed of six different ones corresponding to the optical resonance,the polarization resonance and the mixed resonance,respectively.The composition of the peaks.Interestingly,although the exciton and resonant modes of quantum dots are not directly coupled,they create indirect coupling through the interaction of the cavity fields,resulting in the appearance of mixed resonance.