MASER OSCILLATION AND MICROWAVE SUPER-RADIANCE IN SMALL SYSTEMS OF RYDBERG ATOMS

Superradiance and transient maser action have been obtained at millimeter wavelengths with alkali Rydberg atoms as the active medium. The emission was detected by monitoring the evolution of Rydberg-state populations using field ionization. Because of the strong Rydberg-atom-radiation-field coupling, the number of radiators at threshold is far smaller than in conventional masers. The estimated radiated energy is extremely low, 10 to 103 eV. Applications for spectroscopy and microwave detectors are considered. © 1979 The American Physical Society.