Antilaser: resonance absorption mode or coherent perfect absorption?
N.N. Rosanova,b,c aIoffe Institute, ul. Polytekhnicheskaya 26, St. Petersburg, 194021, Russian Federation bS I Vavilov State Optical Institute, Birzhevaya liniya 12, St. Petersburg, 199034, Russian Federation cITMO University, Kronverksky Pr. 49, bldg. A, St. Petersburg, 197101, Russian Federation
It is shown that the main idea of the recent study of "coherent perfect absorption" coincides with that published in 1962 by A.P. Khapalyuk. Generalization of this approach to the case of layered systems with alternating absorbing and amplifying media needs a more thorough analysis of possible instabilities.