Frequency adding lasers and optical amplifiers

Abstract From the Canadian patent

of the Invention, A method for creating population inversions for use in stimulated emission devices which beam combine, beam clean-up or frequency, up-convert electromagnetic radiation. The invention comprises near resonantly enhanced multiphoton pumping of a multilevel quantum medium with pump beams of appropriate intensities and frequencies detuned from the transition frequencies of the medium. The intensities are orders of magnitude lower than those required for non-resonantly enhanced multiphoton pumping. The detuning is smaller for the maximum multiphoton resonance than for the single photon resonances. Appropriate medium decay constants are required for creating a population …