This volume contains notes based on the lectures delivered at the fourth New Zealand Symposium in Laser Physics, held at the University of Waikato, Hamilton, February 10-15, 1986. At this meeting, about 80 physicists work ing in many parts of the world met to discuss topics of current interest in contemporary laser physics and quantum optics. These symposia, which have been held triennially since 1977, have evolved into an important meet ing ground for experimentalists and theoreticians working in a very rapidly developing field. As the format has evolved, the number of participants, in cluding the number from overseas, has grown steadily, and this year a poster session was included for the first time, enabling a far greater range of topics to be discussed than was possible in the limited lecture time available. At this meeting the major interest of the participants concerned the the oretical investigation of squeezed states of the radiation field and the very recently reported experimental observations of such states. Other related ar eas of work reported here include bistability and chaotic behaviour of optical systems, the quantum theory of measurements, optical tests of general rel ativity, and the current technological limitations governing the stabilization of lasers. The editors would like to thank the participants for providing detailed notes for publication shortly after the meeting, and the various organisa tions that have provided financial support.

Inhalt
I Squeezed States of Light.- Penetrating the Quantum Limit: The Experimentalists' View (With 10 Figures).- Inhibition of Atomic Phase Decays by Squeezed Light: A Direct Effect of Squeezing.- Broadband Squeezing (With 1 Figure).- Theory of Squeezed Light Generation (With 10 Figures).- Experimental Studies of Squeezed-State Generation by Four-Wave Mixing in an Optical Cavity (With 6 Figures).- Intracavity Frequency Doubling for the Generation of Squeezed States of Light (With 6 Figures).- Quantum Noise in Homodyne Detection (With 6 Figures).- Oversqueezing Via Fourth-Order Interaction.- Photodetection and Induced Squeezing.- Generation of Squeezed States: Rydberg Atoms in a High Q Cavity (With 5 Figures).- II Optical Bistability and Chaos.- Single- and Multimode Instabilities in Lasers With 8 Figures).- Ordered and Chaotic Response of a Modulated or Driven NMR Laser (With 9 Figures).- Bistable Operation of an Infrared Dye Laser (With 2 Figures).- Intrinsic Optical Bistability (With 3 Figures).- Chaos in Simple Quantum Systems.- III Fundamental Problems in Quantum Mechanics.- Are There Quantum Jumps? (With 3 Figures).- Modified Optical Bloch Equations for Solids.- Ground State Photons Dressing Atoms and Molecules.- Overdamping and Quasi Quantum Nondemolition Measurements.- First Order Coherence of Vacuum Fluctuations: Optical Pumping Experiments in Presence of Electromagnetic Boundaries (With 5 Figures).- Rydberg States in Laser Fields: Wave Packets and Near-Threshold Phenomena (With 6 Figures).- Squeezing in the Degenerate Parametric Oscillator Using the Positive P-Representation (With 4 Figures).- Quantum Brownian Motion: Recent Developments (With 3 Figures).- Quantum and Many-Body Effects in a Compton Regime Free-Electron Laser (With 4 Figures).- Time-SymmetricElectrodynamics and Quantum Measurement (With 2 Figures).- IV Optical Tests of General Relativity and Other Contributions.- Quantum-Noise Quenching in Correlated Spontaneous Emission Lasers, and Their Application to High-Precision Measurements.- Ring Interferometric Tests of Nonclassical Gravitational Effects.- Fluorescence Enhancement of Rhodamine 6G Molecules in TiO2 Semiconductor Colloid.- Stabilizing Lasers for Applications in Quantum Optics (With 7 Figures).- Index of Contributors.