Microwave Atomic Oscillator Using the Hyperfine Transition of Rb87

A new method of optical detection of the mF 0 mF 0, Delta F 1 ground state magnetic hyperfine transition in alkali atoms, which is important for atomic frequency standards because of its first order independence of an external magnetic field, was investigated. After orientation by optical pumping, a quantum mechanical superposition state is produced by a 90 degree rf pulse. A phase change between mF 0 state and its partner states of the same F value is caused by a microwave field at 6835 Mcsec coupling the two mF 0 states. This phase change is converted into a population change by a second rf pulse to yield a large change in the resonance scattering of the optical pumping light, on the order of that obtained by reversal of the orientation of the vapor. Other methods of optical detection of this resonance were studied. Wall coatings for the inhibition of spin relaxation in confined oriented vapors were studied experimentally.