Maser Oscillation and Microwave Superradiance in Small Systems of Rydberg Atoms

Abstract

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 ${10}^3$ eV. Applications for spectroscopy and microwave detectors are considered.