The Research On The Transparency Phenomena In Hybrid Optomechanical Systems

Cavity optomechanical system is currently the focus of extensive experimental and theoreti-cal investigations and has witnessed impressive and spectacular progress in the recent years.A figurative cavity optomechanical system consists of an optical resonator and a microme-chanical or nanomechanical oscillator,which makes optical degrees of freedom couple with mechanical degrees of freedom,and mutually modulates the cavity field and mechanical os-cillator with each other.The amalgamation of two level atom in optomechanical system can usually enhance the optomechanical coupling between cavity field and mechanical oscil-lator,which can directly enrich various nonlinear effects and be beneficial for the studying of the quantum effects in the optomechanical system like optomechanically induced trans-parency(OMIT)etc.In this dissertation,we mainly study some quantum nonlinear effects in the hybrid cavity optomechanical systems with the special emphasis on the optomechani-cally induced transparency.This dissertation includes 6 chapters where the 3rd,4th,and 5th chapters cover our main jobs in the doctoral study and the 6th chapter presents the summary and some discussions.In Chap.1,we first introduce the background as well as the development of cavity quan-tum optomechanical systems.In particular,we give a brief review of the optomechanically induced transparency and Fano resonances in the cavity optomechanical systems.In Chap.2,we bring in the reader to the field of cavity optomechanical system by intro-ducing the basic concept and knowledge.The mechanical oscillator and the radiation pressure axe first introduced and then the optomechanical system and the relevant experimental ad-vancement are presented.In addition,we,in detail,introduce the dynamic description of the optomechanical system especially including the basic Hamiltonian,optomechanical coupling,quantum Langevin equations,input output formalism and so on.Finally,we give an ex-tensive introduction of the optomechanically induced transparency and the Fano resonances which are closely related to our main jobs.In Chap.3,we have studied the transparency phenomena in the optomechanical system containing N cavities and atoms.We find that the optomechanically induced transparency windows directly depend on the number of cavities involve in the system.In particular,it is shown that the two-level atom,if trapped in the odd labeled cavity,is beneficial to enhance the width of multiple OMIT windows and can induce an extra optomechanically induced transparency window if trapped in any even labeled cavity.In Chap.4,we also investigate the multiple optomechanically induced transparency windows in two coupled optomechanical systems and analytically discuss the significant role of two optomechanical couplings and a mechanical coupling between the two resonators.The presence of these couplings lead to different quantum interference paths and generate the single,double and triple OMIT windows in the probe absorption spectrum.The width of these multiple OMIT windows and the transitions between the different OMIT windows can be effectively controlled by the system’s parameters.In Chap.5,we also study the optomechanically induced transparency and Fano res-onance in an optomechanical system with levitated nanosphere trapped inside Fabry-Perot cavity.We find that the nanosphere independent of the mechanical oscillator plays its own independent role in the output spectra and is responsible for the generation of Fano profiles along with the usual OMIT window.Thus it is shown that the Fano profile and the width of the OMIT window can be controlled simultaneously and independently by appropriate system’s parameters.In Chap.6,we give a summary of our dissertation and give some discussions about the potential applications of our main jobs.