Zeeman Shift Measurement Of Cesium Atom Based On Nanofiber

Using quantum mechanics to explain light,matter and their interactions opens up a new approach to manipulate the quantum states of light and matter.It has led to a broader understanding of quantum physics and the emergence of more advanced technologies governed by quantum rules.Manipulating the quantum states of light and matter is a challenge in contemporary physics.Various techniques are being used to control the interaction of light with matter,including cold atomic physics,cavity quantum electrodynamics(cavity QED),and collective super-radiant emission.In this paper,we use nanofiber to modify the light field,so the light field presents a special distribution.Optical nanofiber has been widely used in optical couplers,optical manipulation and quantum storage due to its advantages of high power density and ultra-low saturation intensity resulted from the sub-wavelength range of beam waist diameter.Optical nanofiber has a strong ability to bind light field and forms optical evanescent field on its surface.The electromagnetic induced transparency of nanofiber,two-photon transition and the all-optical modulation were demonstrated by using this property.In this thesis,the interaction between the optical fiber and the atom is studied by using the strong binding ability of the nanofiber to the optical field,including the absorption and saturation effect of cesium atoms on the nanofiber and the measurement of the Zeeman shift of cesium atoms.Based on the advantages of high power density of nanofiber,we only need the light intensity of navawatt-scale to ensure the smooth progress of the experiment,which is the advantage of studying the interaction between light and atoms compared with space light.The research content of this paper is as follows: 1.Tapered nanofiber is successfully fabricated by flame-brush method.When the nanofiber is fabricated successfully,the diameter measured by the electron microscope is about 500 nanometers,and the transmission rate is up to 99%,which ensures experimental normal progress.2.We built the optical path and vacuum system that meet the experimental requirements.In chapter 3,the absorption saturation characteristics of cesium atoms on nanofiber are investigated.The third chapter is prepared for the experiment of measuring the Zeeman shift of cesium atom based on nanofiber in the fourth chapter.3.The design of heating structure of nanofiber.The temperature of nanofiber should not be too high,which may break up nanofiber due to thermal effect.The surface temperature of the optical fiber should also be higher than the temperature of the cavity,which is to prevent the accumulation of atoms on nanofiber.4.The absorption saturation of cesium atoms on nanofiber was measured at different light intensities and temperatures.The Zeeman frequency shift rates of cesium atoms under different magnetic fields are measured by nanofiber,this method only requires intensity of nanowatt power.