Theoretical Study On The Reflectivity And Transmissivity In Optomechanical System

Quantum cavity optomechanics describes the quantum-mechanical interaction between electromagnetic radiation and mechanical resonator. A fundamental setup of optomechanics contains a laser driven cavity with a moving end mirror. Nowadays, there are number of setup’s exist in cold atom experiment and superconducting microwave circuits, opening with illustrations of laser-cooling and sensitive displacement detection. Thus, one observed that several concepts developed to explain cavity optomechanical system with mechanical oscil-lators have also been developed in the stream of scientific literature related to cold atomic physics. Here we study the effect of the radiation pressure force of light on the mechanical oscillator. Both the properties of light field and the dynamics of the mechanical oscillation are changed from light-matter interaction.In chapter1, we discuss different features of the quantum cavity optomechanical system explored experimentally and theoretically. We also discuss the role of radiation pressure and coupling constant in an optomechanical system. We focus fundamental light-matter interaction in chapter2, in which we study the scattering of a light beam from any object such as dielectric nanoparticle sphere, molecule, atom, nanobeam etc. In this chapter, we also discuss basic formalism of an optomechanical system based on a classical and quantum basis. This formalism is very important for light matter interaction.Cavity optomechanics analysis is quickly approaching the regime where the radiation pressure force of a single photon deflects the oscillator end mirror. In chapter3, we examine an optomechanical cavity, which is coupled to a mechanical oscillator via radiation pressure and use of an external field to drive optical cavity coherently. Our analysis in this chapter is based on the weak opto-mechanical interaction. Due to the action of photon-cavity-induced radiation pressure force, the oscillating mirror will oscillate experiencing harmonic oscilla-tions. Transmission and reflection coefficients calculate analytically for fields as well as for the intensities in the limit of weak mirror-cavity couplings. We also discuss the effect of mirror-cavity coupling on the transmission and reflection. Any dielectric nanoparticle moving inside an optical cavity generates an optical inter-action. In chapter4, we study a cavity optomechanical system, in which we consider a nanoparticle inside an optical cavity that interacts with an external laser driven cavity mode. We study the interaction of light to a mechanical motion of dielectric nanoparticle in an opti-cal cavity. This interaction gives rise to different dynamics that can be used to cool, trap and levitate nanoparticle. Transmission and reflection coefficients calculate analytically for fields as well as for the intensities. In addition, we also study the time evolution of intra-cavity field intensity, particle momentum and position.Finally, conclusions and discussions are presented.