Design and Construction of a High-Precision Atomic Beam Machine for Quantum Optics and Atom Optics Experiments

摘要

We describe the design of an atomic beam machine for metastable helium atoms, optimized for quantum optics and atom optics experiments. The setup produces a highly collimated, monochromatic (single axial velocity), and bright beam of metastable helium atoms. The beam, exiting from a liquid-nitrogen cooled discharge source, is collimated using transverse laser cooling. Zeeman-slowed to an axial velocity between 100 and 300 m/s, prefocussed and funneled by two separate 2-D magneto-optic traps. The (calculated) brightness of the final beam is 1.0 * 10~(11) s~(-1) mm ~(-2) mrad~(-2) at an axial velocity v_(ax) = 250 m/s. Special attention has been paid to the thermal stability and vibration isolation of the setup and to a clean, hydrocarbon-free vacuum. The setup, which has been constructed and is presently undergoing testing, will be used for a variety of cavity QED and atom interferometry experiments. The first experiments which will be performed in the setup are photon number measurements in a high-finesse optical cavity and quantum tomography of atomic (motional) wavepackets. Another application, which we describe here in some detail, is the study of a new type of continuously pumped single-atom laser, operating in the quantized cavity field regime. The system constitutes a true inversionless, two-level, single-atom laser. Its operation is based on the asymmetry between absorption and stimulated emission in a quantized field.