A laser oscillator at 535 nm produced by a chemical process yielding stimulated emission of visible radiation via fast near resonant intermolecular energy transfer comprising the steps of reacting a reaction with a first metal vapor to form metastable states of metal oxides or metal halides, transferring the energy from the metastable states to receptor metal atoms by means of near resonant energy transfer to form electronically excited receptor metal atoms in an inverted configuration, and, through multiple reflection, allowing for the repeated passage of light through the inverted gain medium so as to produce oscillation.