I got my Ph.D.in Physics in 1976 from the University of Rochester, USA, in the field of quantum optics. After a research assistantship at the ETH in Zurich, Switzerland, from 1976 to 1977, I became a professor at the Pontifical Catholic University at Rio de Janeiro, Brazil. In 1994, I became a Full Professor at the Federal University of Rio de Janeiro, Brazil, being elected Emeritus Professor of the same institution in 2021. In the same year, I was hired as part-time Distinguished Professor at the Institute for Quantum Science and Engineering of Texas A&M University. In 2000, I was awarded the Brazilian Grand-Cross of the National Order of Scientific Merit. I was a recipient, in 2001, of the Physics prize of The World Academy of Science (TWAS), and, in 2010, of the Brazilian National Science Prize Admiral Alvaro Alberto, awarded by the Brazilian National Research Council. I have also been involved with science policy, as President of the Brazilian Academy of Sciences (2016-2022) and Secretary-General of TWAS, for the period 2019-2022, and also as member of the board of the International Science Council and committees of the InterAcademy Panel. I am Fellow of the American Physical Society and of Optica (former Optical Society of America). I am a foreign member of the European Academy of Sciences and the Chinese Academy of Sciences.

My research is in the areas of quantum optics and quantum information. I am especially enthusiastic about proposing experiments that probe subtle aspects of the quantum world. More specifically, I have been interested in the role of the environment on the dynamics of several systems. This has involved work on atomic decay, laser and micromaser dynamics, trapped ions, cavity quantum electrodynamics, and entanglement. Interaction with an environment leads to loss of quantum features, a phenomenon known as decoherence. I am particularly interested in the effect of the environment in connection to the classical limit of quantum mechanics, including chaotic systems, and have worked on proposals of experiments on decoherence and for measuring the quantum state of a field in a cavity, which have actually been implemented at Ecole Normale Supérieure, in Paris. More recently, I have been involved in the realization of experiments in the quantum optics lab at the Federal University of Rio de Janeiro, investigating, with twin-photon beams, the detection of entanglement and the relation between local and global dynamics under the action of different kinds of environment. One of the main themes of my research nowadays is quantum metrology, involving both theoretical developments and experimental realizations.