Albert Einstein described the theoretical basis for lasers in 1916. In the 1950s and 1960s, stimulated emission of electromagnetic energy was demonstrated. Light amplification by stimulated emission of radiation (laser) produces light that is coherent, monochromatic and collimated. The photons of laser light lead to photobiomodulation, which stimulates tissue.
This abstract is available by permission of the publisher. Full text is available by subscription.