Adiabatic Rapid Passage in Ruby at 8 mm Wavelengths†

An investigation of adiabatic rapid passage has been made in ruby at 8 mm wavelengths. Performance data are given on a two-level ruby maser operated both as a pulsed amplifier and as an oscillator at these wavelengths. When amplifying, values of gain and bandwidth of up to about 14 ds and 10 Mc/ s at 1-4° k were obtained, giving root gain-bandwidth products of up to about 50 Mc/ s. In preliminary experiments using the maser as an oscillator output powers of about 70 / z/ v at 33-1 Gc/ s were obtained at 1. 4° K. The inversion technique used, which incorporates magnetic field modulation with the use of the crystal as a cavity, could be readily scaled to considerably higher frequencies.