FROM LASERS AND MASERS TO PHASEONIUM AND PHASERS

An ensemble of three-level atoms having a ground state doublet and a far removed excited state displays unusual behavior when the doublet is coherently prepared, e.g., cancellation of absorption and an enhanced index of refraction. Similar effects can be observed using a coherently prepared excited state doublet and a far removed ground state. Such a phase coherent atomic ensemble ("phaseonium" for short) is, in a real sense, a new state of matter and lasers and masers based on such a medium exhibit many unusual features such as lasing without population inversion and quenching of the Schawlow-Townes quantum noise. Such phaseonium based lasers and masers ("phasers" for short), also hold promise for sources of bright squeezed light. The potential application of these ideas to high precision magnetometry and particle acceleration are particularly interesting.