PROBING THE QUANTUM STATE IN A CAVITY VIA ATOMIC 2-PHOTON TRANSITIONS

This paper contains a theoretical treatment of a scheme for determinin g phase-dependent features of a single mode of quantized light fields in general states. The proposal involves using a three-level atom, in a cascade configuration, as a detector. The cascade atom, which is on two-photon resonance with the field, is prepared in a coherent superpo sition of the upper and lower levels, and detection involves measuring the probability of the cascade atom being in the upper level. The res ults depend on the phase difference between the amplitudes for the fie ld being in N and N + 2 photon states in the number state basis, and a re important in describing nonclassical states, such as squeezed and S chrodinger cat states. The analysis is based on a standard dressed ato m model approach and a Fourier treatment of the measured signal. The e xperimental possibilities of realizing this scheme are also discussed.