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Document Type:Latin Dissertation
Language of Document:English
Record Number:55423
Doc. No:TL25377
Call number:‭3461786‬
Main Entry:Mark Vilensky
Title & Author:Manipulating Neutral Atoms and Molecules by Strong Non-Resonant Laser FieldsMark Vilensky
College:The Weizmann Institute of Science (Israel)
Date:2008
Degree:Ph.D.
student score:2008
Page No:62
Abstract:Manipulating neutral particles by laser light has been of great interest during the last decade. The main effort is placed on atom cooling together with atomic beam deceleration, deflection, focusing, mirroring, and related aspects of atom optics. In the present thesis we provide indepth analytical and numerical analysis of the optical shaker approach to non-resonant laser cooling, and propose new methods for deceleration and cooling atoms/molecules in a feedback-controlled bistable cavity. Moreover, application of the latter technique to cooling of a micromechanical object is also proposed and analyzed. In the Introduction we review the current state-of-the-art cooling techniques and provide a brief history of their development. Chapter I presents in-depth analysis of the optical shaker operation; we study the issue of the detection of the dipole force in the far zone, which is the main building block of the optical shaker technique. The effects of the finite response time of the detectors and of the phase modulator are modeled numerically. The thresholds for cooling are estimated analytically and verified numerically. Minimal requirements for the stability of the laser sources are formulated. Perturbation theory analysis of the heating rate of an ensemble of particles embedded in a non-stationary sinusoidal (non-harmonic) potential is provided. In addition, a preliminary study of the adaptive cooling strategy is outlined. Chapter II presents a new method for deceleration of a single particle and cooling of an ensemble of particles in a bistable optical cavity. Optical bistability is achieved by non-linear feedback control of the field incident on the cavity. The technique realizes cavity-induced Sisyphustype cooling mechanism. This approach is rather generic because of its off-resonance nature. The bistable cavity introduces a “dry friction” stopping force, and requires a relatively “bad cavity” for its implementation. We provide an analytical estimate for the stopping force for a single particle. Full numerical simulation of a single particle deceleration in the strong and weak coupling regimes was done. We also demonstrate efficient cooling of an ensemble of particles in a bistable cavity. In Chapter III we propose a novel method for cooling a micromechanical object, such as micromirror or a cantilever in a cavity with dispersive optical bistability. In this case, the feedback controls the phase of the intracavity field. Stability analysis of such an opto-mechanical system was performed in order to find the parameters required for the mirror cooling. The mechanism of the feedback enhanced cavity cooling is studied in detail.
Subject:Pure sciences; Laser cooling; Particle cooling; Particle deceleration; Low Temperature Physics; Optics; 0598:Low Temperature Physics; 0752:Optics
Added Entry:Y. A. Prior, Ilya
Added Entry:The Weizmann Institute of Science (Israel)