Atom optics has seen fast development and vast achievements,and has wide application prospects.The basic principles of the manipulation and control of cold atoms using magnetic and laser fields are briefly introduced,followed by a detailed review of recent progress of geometric and wave atom optics as well as potential applications and the development of atom optics devices Topics include the reflection of atom beams and mirrors,the deflection(refraction) and focusing of atom beams and lenses,the diffraction of atom matter waves and gratings,atom interferometers,and atomic holography.
Atom optics has seen fast development and vast achievements,and has wide application prospects.The basic principles of the manipulation and control of cold atoms using magnetic and laser fields are briefly introduced,followed by a detailed review of recent progress of geometric and wave atom optics as well as potential applications and the development of atom optics devices Topics include the reflection of atom beams and mirrors,the deflection(refraction) and focusing of atom beams and lenses,the diffraction of atom matter waves and gratings,atom interferometers,and atomic holography.
Matter wave optics has a long tradition spanning over many decades starting with electron and ion optics. These techniques now find commercial applications in microscopy and lithography. Neutron optics contributed many beautiful experiments that tested many fundamental principles in quantum mechanics. Over the last decade the field of atom optics has been developed. In particular the availability of narrowband tunable laser sources has opened up the addressing of the internal electronic degrees of freedom of the atoms and as a result, the manipulation of their trajectories. The dissipative nature of the atom light interaction is used for laser cooling methods e.g. to collimate atomic beams to a high brightness whereas the dispersive nature of the interaction is used to realize different atom optical components like lenses, beam-splitters and mirrors. Consequently atom optics is now at a stage where applications of those elements in more complex systems are studied. An overview of recent developments is given. This includes atom interferometry and atom lithography experiments and experiments with a quasi 2D gas of ultra cold atoms in planar waveguides. Future directions and applications are outlined.
Interference with atomic and molecular matter waves is a rich branch of atomic physics and quantum optics. It started with atom diffraction from crystal surfaces and the separated oscillatory fields technique used in atomic clocks. Atom interferometry is now reaching maturity as a powerful art with many applications in modern science. In this review the basic tools for coherent atom optics are described including diffraction by nanostructures and laser light, three-grating interferometers, and double wells on atom chips. Scientific advances in a broad range of fields that have resulted from the application of atom interferometers are reviewed. These are grouped in three categories: (i) fundamental quantum science, (ii) precision metrology, and (iii) atomic and molecular physics. Although some experiments with Bose-Einstein condensates are included, the focus of the review is on linear matter wave optics, i.e., phenomena where each single atom interferes with itself.
The Optics and Interferometry with Atoms symposium provided an opportunity for a general audience to learn about develop ments of this new field.The goal of atom optics is to do with atoms what usual optics does with photons, e.g., reflection, refraction, focusing, interference.Two techniques have been used up to now in order to act on atomic trajectories: interaction with quasiresonant laser light and interaction with diffracting fabricated microstructures.In his introduction, J. Mlynek (Constance) explained that several basic elements of atom optics have already been demonstrated (mirrors, lenses, beam splitters, interferome ters) but many improvements are still expec ted.He also anticipated exciting applications.For instance, atomic microprobes will use particles much less energetic that electronic microscopes (meV instead of KeV) and ato mic interferometers will permit highly sensi tive measurements of gravitational or Inertial effects, both for detection purposes and for fundamental tests of relativity.An example of an atomic interferometer, based on a idea by C. Borde using Ramsey fringes, was described F. Riehle (PTB, Braunschweig).Sensitivity to rotations has been demonstrated, light-shifts measured, and a new experiment based on cold, trap ped atoms instead of an atomic beam is in progress.J. Robert (Paris-Nord) reviewed the basic principles of Stern-Gerlach inter ferometry for application to the so-called "scalar Bohm-Aharonov effect"; a new scheme involving four interaction zones should yield new results.Finally J. Dalibard (Paris) described the atomic cavity based on a concave mirror for bouncing atoms (Fig. 1).It opens the path to the observation of multiple atomic multiple interferences, i.e., observing the modes of an atomic cavity.The ultimate goal would be to accumulate many bosonic atoms in the same mode to realise the atomic equivalent of a laser mode filled with many photons.
Atom Optics is a new branch of Atomic Physics, where one tries to act upon atoms, likewise one can act upon light (photons) in ordinary optics. The goal is therefore to reflect, focus, diffract, make interfere atoms1 .Afew years ago, this was considered as a fundamental goal, as had been the case decades ago for electron optics, or neutron optics. Indeed, it is always important to investigate the quantum behaviour of larger and larger objects, and studying the wave like behaviour of atoms has attracted a lot of attention. Moreover, atoms are objects that are coupled with the environment in a controlable way, in particular via quasi-resonant interaction with light. There is thus a hope to investigate how this coupling with the environment is relevant to the old problem of the division between the quantum world and the classical world2 ,and how it is related to the question of quantum decoherence. To keep in the domain of Atom Optics, the question of the preservation of coherence of the de Brogue waves describing the atomic motion is crucial. Another basic issue is the question of the collisions between atoms, or between an atom and a surface, when the atom is described as a matter-wave. From this point of view, the very interesting recent results in the domain of cold atoms collisions are only a part of what will probably come out, and new approaches may be fruitful. For instance, some collision effects may be considered as non-linear effects of atom optics... On the other hand, almost from the start, Atom Optics has been a domain where the question of applications has been raised. The experience of the many useful applications existing in the domain of electron and neutron optics has clearly shown the way. A first reason for expecting interesting applications to atom optics is the small value of the de Brogue wavelength, in the nanometer range or below, even at very low energies. This opens for instance the possibility of high resolution lithography, or of nanoprobes, at energies low enough to have a soft, non damaging interaction with a surface. Another important class of applications is in atomic interferometry. It can be shown that atomic interferometers (using atoms of mass Mat) are much more sensitive to inertial or gravitational effects3 than photonic interferometers (using photon of energy hw), by a ratio of the order of MatC2 / ho) . Note that this statement is true only under the condtion that the atomic and photonic interferometers under comparison have equivalent geometries, so that present day interferometers do not yet take full advantage of the 1011 factor of potential improvement. However, impressive results have already be demonstrated6. As a matter of fact, many of the papers presented in this symposium are linked to applications, either with atomic interferometers, or related to the possibility of deep focusing of an atomic beams. Most of these applications a Unite de recherche associée au CNRS can be easily understood by analogy with photon optics. However, there are also several features of atom optics that have no analogy in photon optics. The most important one is probably the possibility to increase the luminosity of an atomic beam (i.e. the flux of atoms per per unit time, surface, and solid angle) or —equivalently — to increase the atomic density in the phase space. This is possible by use of laser cooling, which is a dissipative process, and therefore is not constrained by the Liouville theorem. Another distinctive feature of atom optics —this one not particularly an advantage —is the lack of a sudden interface, that would be analogous to a glass-vacuum interface for light. By sudden interface, we mean that some characteristic parameter relevant to the propagation (the index of refraction in the case of light) changes on a scale small compared to the wavelength of the waves that propagate. In atom optics, the interfaces are usually soft, since the potentials acting on the atomic motion usually change on a scale large compared to the de Broglie wavelengths. In this overview, I intend to recall some basic principles of atom optics, and to point out some important analogies and differences with photon optics4 .Iexpect this discussion to be illustrated by the various presentations at this symposium, for which I hope to offer a framework. In addition, I will take the liberty to illustrate my presentation by some examples chosen among results obtained recently in my laboratory, on the subject of atomic mirrors. The comparison between atom optics and photon optics would of course be incomplete if I would not adress the question of the impact of Bose Einstein condensates onto Atom Optics. As many of us, I am convinced that we are assisting to a revolution as important for Atom Optics as the invention of the laser in the domain of Photon Optics, and we are lucky to have a full session on this hot subject.
Clouds of cold atoms, collected and refrigerated by laser light, can be cooled to nanoKelvin temperatures. This has created the new field of atom optics where cold atoms are manipulated, much as photons are controlled in traditional optics using mirrors, lenses, and gratings. It is also becoming possible to confine and manipulate atoms in extremely small traps and waveguides, which give access to de Broglie wave physical optics. Atoms flowing in such structures could provide a new technology based on the flow and quantum interactions of neutral atoms. Atom 'chips' could lead to integrated atom interferometers and even possibly to a quantum information processor.
The basic concepts and principles, experimental schemes and results as well as recent progress of manipulation and control of cold neutral molecules and their geometric molecule-optical devices in the world are introduced. These contents mainly include: electrostatic guide of cold polar molecules and its molecular pipe, laser deflection (refraction) of neutral molecules and its molecular prism, laser focusing of neutral molecules and its molecular lens, electrostatic and magnetic reflection of neutral molecules and its molecular mirror, and laser rotation manipulation of cold molecules and its optical centrifuge, and so on.