Efficient Preparation And Optimization Of Atomic Internal States In High-finesse Optical Microcavity

Quantum Electrodynamics(QED)mainly studies the quantum behavior of atoms interacting with light or electromagnetic fields in specific spaces,such as optical microcavities or high-quality microwave cavities.The control of the atomic state can be achieved through the strongly coupled cavity QED system,which can be applied to quantum entanglement,precision measurement,and quantum computing.However,all these works are based on the manipulation of neutral atoms in the optical microcavity.The key factor is whether there is a strong coupling between the cavity field and the atoms.With the development of cold atom manipulation technology,people can effectively cool atoms to near absolute zero,and can also initialize atomic state through the optical pumping effect.In the cavity QED system,limited by the limited intervention space of the optical microcavity,the conventional optical pumping method for preparing the atomic ground state is unsuitable.We propose to use the light field(455 nm,1 2 3 26 S ?7P),which transmits the cavity mirror with high efficiency and couples with higher atomic excited states,to prepare the cesium atoms in the cavity to a specific Zeeman state.A home-made 455 nm external cavity diode laser(ECDL)is used to do this work.The specific works of the thesis are:(1)An ECDL with type of Littrow is designed and built.The wavelength is 455 nm and maximum output power is 80 m W.It can be stably locked to the cesium atomic transition line.(2)The 455 nm laser and a 894 nm repumping laser are used to prepare the internal state of cesium atom in an optical microcavity.A theoretical model is established to analyze the experimental results.The polarizability of the atoms in the cavity is =0.7DiffP,which corresponds population of 85% for atom in state1 26,4,4FS F(28)m(28)-.Finally,the effects of the quantized magnetic field gradient,the 455 nm pump light intensity,and the polarization of the pump light on the atomic polarization efficiency are experimentally studied.