Nanotechnology with atom optics

A brief review of atom optics is presented, with emphasis on how it can be applied in the field of nanotechnology. Two specific examples are discussed: laser-focused atomic deposition and deterministic production of single atoms. Results are summarized for these two techniques, and discussion is presented on how they can impact progress in the development of nanotechnology.     

Anomalous transmission in atom optics

Abstract

Anomalous transmission for X-rays in crystals as discovered by Borrmann can also be observed for atoms interacting with a standing light wave on resonance. It may be interpreted as a manifestation of a grey state. We describe phenomena based on anomalous transmission for various regimes of the atom-light interaction and elucidate these by numerical calculations for argon and calcium. The grey state in anomalous transmission is linked to the dark state in velocity selective coherent population trapping in atomic threelevel A systems.     

Nanofabricated atom optics: Atom chips

Abstract

Small tight trapping and guiding potentials can be created for neutral atoms moving microns above surfaces patterned with nanofabricated charged and current-carrying structures. Surfaces holding such structures form atom chips which, for coherent matter wave optics, may form the basis for a variety of novel applications and research tools, similar to integrated circuits in electronics. In this paper we describe the basic principles of atom chip experiments.     

Lava lamp optics

An interesting optical focusing effect occurred in the early heating phases of a simple model of a lava lamp that was constructed to demonstrate convection effects. During this early heating phase, the interface between the two immiscible liquids was found to form a surface of rotation with a conic cross section that acted as a mirror to produce an excellent image of the filament of the bulb within the lower liquid. The relevant features of the lamp construction are discussed briefly, and photographs of this focusing effect are shown. A simple analysis is presented that transforms the photographed cross section of the liquid interface into the true cross section by removing the effect of the cylindrical lens formed by the fluid-filled bottle, and the resulting cross section is then fitted to the shape of an ellipse. The possible cause for the shape of this liquid interface is discussed and compared and contrasted with the somewhat analogous situation of a stretched circular membrane that is subjected to different gas pressures on either side of the membrane.     

Dissipative properties of nanostructured materials

Results of studies of the effect of the size of micro-and substructure elements (grains, twin domains, etc) on the dissipative properties of materials have been generalized. It has been shown that when the size of the microstructure elements of materials decreases to nanoscale, their dissipative properties change qualitatively. This is due to a change in mechanical energy dissipation mechanism on the transition of material to nanostructured state. The possibility of creating a new class of highly damping hard coatings based on nanostructured materials is discussed. __________ Translated from Problemy Prochnosti, No. 5, pp. 96–104, September–October, 2008.     

Emerging correlation optics

This feature issue of Applied Optics contains a series of selected papers reflecting the state-of-the-art of correlation optics and showing synergetics between the theoretical background and experimental techniques.     

Digital Fourier optics

Analog Fourier optical processing systems can perform important classes of signal processing operations in parallel, but suffer from limited accuracy. Digital-optical equivalents of such systems could be built that share many features of the analog systems while allowing greater accuracy. We show that the digital equivalent of any system consisting of an arbitrary number of lenses, niters, spatial light modulators, and sections of free space can be constructed. There are many possible applications for such systems as well as many alternative technologies for constructing them; this paper stresses the potential of free-space interconnected active-device-plane-based optoelectronic architectures as a digital signal processing environment. Implementation of the active-device planes through hybridization of optoelectronic components with silicon electronics should allow the realization of systems whose performance exceeds that of purely electronic systems.     

Terahertz graphene optics

The magnitude of the optical sheet conductance of single-layer graphene is universal, and equal to e ²/4? (where 2??? = h (the Planck constant)). As the optical frequency decreases, the conductivity decreases. However, at some frequency in the THz range, the conductivity increases again, eventually reaching the DC value, where the magnitude of the DC sheet conductance generally displays a sample- and doping-dependent value between ??e ²/h and 100 e ²/h. Thus, the THz range is predicted to be a non-trivial region of the spectrum for electron transport in graphene, and may have interesting technological applications. In this paper, we present the first frequency domain measurements of the absolute value of multilayer graphene (MLG) and single-layer graphene (SLG) sheet conductivity and transparency from DC to 1 THz, and establish a firm foundation for future THz applications of graphene.      

Blazed diffractive optics

Diffractive optical elements with blazed profiles can, in theory, have 100% relative efficiency. We review several methods for making such elements and compare their advantages and limitations. Our emphasis is on processes to produce elements other than those with approximate, stepped surfaces, such as binary optical elements. For optical methods, we offer an expression relating the maximum numerical aperture of a diffractive lens with a given maximum efficiency to the numerical aperture of the recording system.     

Precision molded-glass optics

Results achieved in high-precision molding of glass lenses are reported. The work concentrated on a 0.4- N.A. 8-mm diam lens with spherical surfaces. The glass is a specialty glass composition of index (d-line) 1.604 and Abbe number 50. Typical design tolerances which have been achieved in the molded glass lenses include relative surface figure replication of 0.06 Aim, thickness and diameter tolerances of A+/-10 Am, wedge of <10-3 rad, birefringence of less than one one-hundredth wave, and index homogeneity in the sixth decimal place. These results are directly applicable to molding precision glass aspheric lenses of similar tolerances.     

Dissipative aspects in thermographic methods

Object of this paper is to emphasize some dissipative aspects of steels in high cycle fatigue from the thermographic point of view by relating anelastic and microplastic behaviours to loading levels respectively below and above the fatigue limit. To this aim, the Two Curves Thermographic Method has been modified by using both a parabola and a power curve as regression laws instead of the traditional linear ones. Two new thermal parameters have also been considered, the thermal increment and the subtended area by the thermal profile at a very low number of cycles. Experimental data referred to C45 standard and 25CrMo4 notched steel specimens have been processed using both original and modified Two Curves methodologies and both traditional and new thermographic parameters. All changes introduced in the present paper provide good results both in terms of fatigue limit values and for as concerns the rapidity of the fatigue tests.     

A Smooth Dissipative Region Model

A Barenblatt model of the dissipative region at the edge of a mode I crack under small scale yielding is established, so that stress gradient and displacement gradient continuity prevail along the symmetry plane. The resulting model thus connects smoothly to adjacent material and it displays exceptionally smooth opening.     

Applied optics of optics and opticists. Physics and street lighting

Sodium lamps for street lighting have been produced by Philips for several decades. Continuing research has improved the quality of these lamps and modified them to meet the demands of professional users.     

Dissipative quartz transducers of mechanical energy

Translated from Izmeritel'naya Tekhnika, No. 3, pp. 49–50, March, 1992.