Summary form only given. A brief history of the laser cooling and trapping of atoms will be presented, covering some of the cooling and trapping techniques that have been developed over the past 15 years. The cooling and trapping technology is already being applied in numerous areas of science and engineering. Applications to be discussed include atomic clocks, atom interferometers for inertial sensors and for the measurement of the fine structure constant, as well as studies in polymer dynamics and protein motion.
Summary form only given. A brief history of the laser cooling and trapping of atoms will be presented, covering some of the cooling and trapping techniques that have been developed over the past 15 years. The cooling and trapping technology is already being applied in numerous areas of science and engineering. Applications to be discussed include atomic clocks, atom interferometers for inertial sensors and for the measurement of the fine structure constant, as well as studies in polymer dynamics and protein motion.
Summary form only given. Techniques for cooling and trapping atoms now provide unique capabilities for the manipulation of atoms. In particular, they make possible very low temperatures, extraordinarily high atomic phase space densities, and long perturbation-free observation times. These capabilities enable one to carry out many new measurements on atoms with great precision and/or in entirely new regimes of temperature and density. This tutorial will concentrate primarily on the practical aspects of how to apply current laser cooling and trapping techniques. This will include descriptions of the various techniques and their capabilities, as well as a discussion of tradeoffs between price, complexity, and various performance parameters. Finally, I will briefly discuss how these techniques are applied in a number of specific cases including cold collisions, precision measurements including atomic clocks, atom interferometry, collecting radioactive isotopes, and the creation of Bose-Einstein condensates.
A review is presented of some of the principal techniques of laser cooling and trapping that have been developed during the past 20 years. Its approach is primarily experimental, but its quantitative descriptions are consistent in notation with most of the theoretical literature. It begins with a simplified introduction to optical forces on atoms, including both cooling and trapping. Then its three main sections discuss its three selected features, (1) quantization of atomic motion, (2) effects of the multilevel structure of atoms, and (3) the effects of polychromatic light. Each of these features is an expansion in a different direction from the simplest model of a classical, two-level atom moving in a monochromatic laser field.
As a matter of fact, the laser cooling and trapping has already been widely used in various fields in advanced atoms controlling. With this in mind, this study gives a systematical analysis of the principle of laser cooling and trapping, and the development of them in the recent years. To be specific, this study will discuss the applications that has invented in the recent year based on the laser colling and trapping (especially for the state-of-art facilities), and makes a comparison between the concepts of laser cooling and laser trapping accordingly. Then, based on the analysis and evaluations, the limitations of laser cooling and laser trapping have been shown, and the future outlooks are also claimed and demonstrated as well. To sum up, the study concludes by discussing the limitations of these techniques, and gives some methods to solve these issues. Overall, these results shed light on guiding further exploration of laser cooling and trapping.
Recently, laser cooling methods have been extended from atoms to molecules. The complex rotational and vibrational energy level structure of molecules makes laser cooling difficult, but these difficulties have been overcome and molecules have now been cooled to a few microkelvin and trapped for several seconds. This opens many possibilities for applications in quantum science and technology, controlled chemistry, and tests of fundamental physics. This article explains how molecules can be decelerated, cooled and trapped using laser light, reviews the progress made in recent years, and outlines some future applications.
An advanced computer code is undergoing development for numerically simulating laser cooling and trapping of large numbers of atoms. The code is expected to be useful in practical engineering applications and to contribute to understanding of the roles that light, atomic collisions, background pressure, and numbers of particles play in experiments using laser-cooled and -trapped atoms. The code is based on semiclassical theories of the forces exerted on atoms by magnetic and optical fields. Whereas computer codes developed previously for the same purpose account for only a few physical mechanisms, this code incorporates many more physical mechanisms (including atomic collisions, sub-Doppler cooling mechanisms, Stark and Zeeman energy shifts, gravitation, and evanescent-wave phenomena) that affect laser-matter interactions and the cooling of atoms to submillikelvin temperatures. Moreover, whereas the prior codes can simulate the interactions of at most a few atoms with a resonant light field, the number of atoms that can be included in a simulation by the present code is limited only by computer memory. Hence, the present code represents more nearly completely the complex physics involved when using laser-cooled and -trapped atoms in engineering applications. Another advantage that the code incorporates is the possibility to analyze the interaction between cold atoms of different atomic number. Some properties that cold atoms of different atomic species have, like cross sections and the particular excited states they can occupy when interacting with each other and light fields, play important roles not yet completely understood in the new experiments that are under way in laboratories worldwide to form ultracold molecules. Other research efforts use cold atoms as holders of quantum information, and more recent developments in cavity quantum electrodynamics also use ultracold atoms to explore and expand new information-technology ideas. These experiments give a hint on the wide range of applications and technology developments that can be tackled using cold atoms and light fields. From more precise atomic clocks and gravity sensors to the development of quantum computers, there will be a need to completely understand the whole ensemble of physical mechanisms that play a role in the development of such technologies. The code also permits the study of the dynamic and steady-state operations of technologies that use cold atoms. The physical characteristics of lasers and fields can be time-controlled to give a realistic simulation of the processes involved such that the design process can determine the best control features to use. It is expected that with the features incorporated into the code it will become a tool for the useful application of ultracold atoms in engineering applications. Currently, the software is being used for the analysis and understanding of simple experiments using cold atoms, and for the design of a modular compact source of cold atoms to be used in future research and development projects. The results so far indicate that the code is a useful design instrument that shows good agreement with experimental measurements (see figure), and a Windows-based user-friendly interface is also under development.