Abstract
A summary is given of the lectures and papers presented at the Sixth International School on Coherent Optics (Quantum Optics '85), Ustron, Poland, on September 19–26, 1985. Recent progress in theoretical and experimental quantum optics is reported under the headings of quantum statistical properties of optical fields, appearance and properties of chaos in quantum systems, influence of high-power radiation on the relaxation processes, nonlinear and multiphoton processes.