Valentin A. Fabrikant: negative absorption, his 1951 patent application for amplification of electromagnetic radiation (ultraviolet, visible, infrared and radio spectral regions) and his experiments
J. Eur. Opt. Soc.-Rapid Publ., 5 (2010) 10045s
DOI: https://doi.org/10.2971/jeos.2010.10045s