The N- and CPT- joint resonance: Theory, experiment and implications for novel compact frequency references.

There has been considerable recent interest in the use of the hyperfine N-resonance in clock applications. We describe the solution of a quantum optics model of the joint N- and CPT- optical resonance with particular attention to its lineshape and lightshift/detuning shift behavior. Recent experimental progress allows a direct detailed test of aspects of this theory. This has led to a preliminary view of the promise and problems of this approach to compact frequency standards.