This talk will present the first achievements in experimental quantum optics, with the realization of squeezed light and quantum correlated beams for continuous variables, and the generation of single photons, and twin and entangled photons, leading to groundbreaking results in basic quantum physics as well as in applications. Then it will show the impressive progress in the development of novel quantum optical systems allowing for the demonstration of more fundamental properties of quantum mechanics and major advances in quantum measurement, communication, simulation and computing.