Modulation And Optimization Of Quantum Optical Properties In Cavity Optomechanical System

Cavity optomechanical system(COMS)mainly studies the interaction between optical cavity field and mechanical system.With the continuous development of the laser technologies and the micro-fabrication technologies,COMS has made remarkable achievements and breakthroughs in experiments.Due to the compatibility of COMS,the cavity and nonlinear mediums can be combined to form a hybrid COMS.At the same time,a great range of the quantum effects appear,such as atom-assisted mechanical cooling,the all optically controlled phonon blockade,atom-enhanced photon-phonon coupling strength,the generation of nonclassical phonon states,and optomechanically induced transparency and fast-slow light effect.These researches have promoted the development of quantum science in signal processing and propagation,quantum sensing and precision measurement.In this thesis,we mainly research the optical properties of first-order and second-order sideband in hybrid COMS.The specific research contents are as follows:Firstly,we study the optomechanically induced transparency(OMIT),fast-slow light and second-order sideband generation in the hybrid Laguerre-Gaussian rovibrational cavity.There are two windows due to two mechanical modes in this system,i.e.,double-OMIT is realized in this system.The effects of mechanical field and optical parametric amplifier on the transmission spectrum are discussed.The results show that the widths and heights of two transparent windows can be changed by adjusting the amplitude and phase of the mechanical field,and the transition from optomechanically induced absorption to transparency and amplification is realized.Selecting appropriate gain and phase of the optical parametric amplifier,mechanical field can modulate the group delay at resonant point,and the conversion between fast and slow light can be accomplished by tuning mechanical field.In addition,the efficiency of the second-order sideband generation can be adjusted by mechanical field,and it can be enhanced significantly due to the optimization of optical parametric amplifier.Then,we investigate the optomechanically induced transparency and group delay in loop-coupling interaction cavity optomechanical system.Since the system has a pair of PT-symmetric mechanical resonators,there is exceptional point.Tuning the coupling strength between two mechanical resonators,the system changes from the PT-broken phase to the PT-unbroken phase.The transmission spectrum displays the transition from single to double transparency windows.Adjusting the phase of the mechanical field can optimize the changes of transmission rate and obtain optomechanically induced transparency windows at different frequencies.By selectively driving two mechanical oscillators,the group delay at the resonant point can be controlled,and changing the power of the driving field can achieve the conversion of group delay between fast and slow light.