Study On Quantum Cavity Optomechanical System Cooling Inweak Coupling Regime

Cavity optomechanical system is coupled system of light field and mechanical field. It can be used for regulation of macroscopic quantum mechanical systems. The cavity optomechanical system has great value in the field of communication. For these purposes, a crucial step is to cool the mechanical system to its quantum ground state. This paper studies the cooling of the F-P cavity optomechanical system in the weak coupling regime, including cooling of the single-beam cavity optomechanincal system and the two-beam cavity optomechanincal system.In the first part, we determine the Hamiltonian of single-beam cavity optomechanincal system, according to the Hamiltonian derive the quantum Langevin equations; Then we use the perturbation method to solve quantum Langevin equations and get the radiation pressure and the noise spectral density of the radiation pressure. Getting the average number of phonons with the steady state equation of the system, and using the quantum Langevin equations derived quantum noise spectral density of the mechanical vibration. Finally, analysis the effect of the various parameters for the cooling of the single-beam cavity optomechanincal system.In the second part, we determine the Hamiltonian of two-beam cavity optomechanincal system analog the Hamiltonian of single-beam cavity optomechanincal system, according to the Hamiltonian derive the quantum Langevin equations; Then using the perturbation method to solve quantum Langevin equations and get the radiation pressure and the noise spectral density of the radiation pressure. Getting the average number of phonons with the steady state equation of the system, and using the quantum Langevin equations derived quantum noise spectral density of the mechanical vibration. Finally, analysis the effect of the various parameters for the cooling of the two-beam cavity optomechanincal system, and Compare the cooling effect of the single-beam cavity optomechanincal system and the two-beam cavity optomechanincal system.