Abstract

The quantum nature of light with its dual (wave and particle) aspects has been recognized since the early days of quantum physics and directly revealed over the last thirty years by a variety of beautiful quantum optics experiments. Some can be viewed as “thought experiments” coming of age, which illustrate fundamental concepts of quantum theory. Others demonstrate that the “quantumness” of light can be used in practice to implement secure ways for optical communication (quantum cryptography) or to increase the precision of some measurements (noise reduction below the standard quantum limit).

© 2009 IEEE