ISSN:0950-0340    

DOI:10.1080/09500349014551911

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Features and applications of the laser scanning microscope are described, focusing on confocal imaging, the image contrast enhancement effect and three-dimensional surface profile measurement. A longitudinal resolution of 0·01 μm is obtained using a surface profilometer with a position-sensitive detector.

ISSN:0950-0340    

DOI:10.1080/09500349014551921

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

We use a new limiting procedure, developed to study quantum-optical phase, to examine canonically conjugate operators in general. We find that Dirac's assumption that photon number and phase should be canonically conjugate variables, similar to momentum and position, is essentially correct. The difficulties with Dirac's approach are shown to arise through use of a form of the canonical commutator which, although the only possible form in the usual infinite Hilbert space approach, is not sufficiently general to be used as a model for a number-phase commutator. The approach in this paper unifies the theory of conjugate operators, which include photon number and phase, angular momentum and angle, and momentum and position as particular cases. The usual position-momentum commutator is regained from a more generally applicable expression by means of a domain restriction which cannot be used for the phase-number commutator.

ISSN:0950-0340    

DOI:10.1080/09500349014551931

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The quantum mechanical master equation for a single two-level atom in a single-mode optical cavity is numerically solved in both the quantum and the semiclassical limits. The quantum limit of few cavity photons shows semiclassically forbidden behaviour such as steady state two-level population inversion. Qualitatively new fluorescent spectra, having sidebands broadened by the cavity interaction, also occur. The quantum theory of the single-atom laser with injected signal is presented. At the interface between its quantum and semiclassical dynamics we elucidate the signature of semiclassical limit cycles.

ISSN:0950-0340    

DOI:10.1080/09500349014551941

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

This paper gives an introduction to quantum noise and the limits it places on optical measurements. Squeezed states of light, and their representation on phasor diagrams, are then introduced. The use of squeezed states to improve interferometric measurements is described. Quantum non-demolition measurements are discussed, with particular reference to their use in high sensitivity absorption experiments. Finally, sources of some other types of non-classical light and possible experiments making use of these sources are considered.

ISSN:0950-0340    

DOI:10.1080/09500349014551951

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Observations of optical nutations from the NaD2line excited by resonant, π-polarized light have indicated that the oscillations consist of essentially one frequency. Considering the complexity of the energy-level configuration associated with this line, the experimental results are surprising. However, it is shown that this pseudo-two-state behaviour is predicted by both a semiclassical theory and a completely quantum electrodynamic approach when the intensity of the light is above a moderately valued threshold, namely, when the power broadening is greater than the hyperfine splitting of the upper states.

ISSN:0950-0340    

DOI:10.1080/09500349014551961

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The quest to detect gravitational radiation is on the threshold of a new era. Technological developments in the 1980s have led to the point where it is now possible to design an instrument based on the Michelson interferometer which should not only be able to detect gravity waves but should function as an astronomical observatory. Stimulated by the need for a southern hemisphere facility, the Australian National University in collaboration with the University of Western Australia is poised to enter this exciting field. Here, we will briefly describe the principle of operation of these giant laser interferometers and examine performance limits imposed by the Heisenberg uncertainty principle.

ISSN:0950-0340    

DOI:10.1080/09500349014551971

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

A superelastic electron-scattering technique is described in which electrons are scattered from optically pumped sodium atoms. The scattering parameters derived from these experiments are shown to provide a sensitive and dynamic description of the excited 32P state of the sodium atom. These parameters are compared with those derived from electron-photon coincidence experiments which are the time reversed equivalent of the present experiments. Although the present results agree with the previous data, the much larger kinematic range of the present work indicates that optical pumping will be the technique of choice for future measurements. The parameters are also compared with those predicted by a coupled-channels theory where fair agreement is found.

ISSN:0950-0340    

DOI:10.1080/09500349014551981

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The non-coplanar symmetric (e, 2e) reaction at several kilovolts is understood so well that it provides an accurate and sensitive tool for observing the motion and correlation of electrons in atoms and molecules. Examples are given of both the determination of experimentally defined orbitals; which are equivalent within experimental error to orbitals calculated by appropriate variational methods, and of quantities dependent on initial- and final-state correlations.

ISSN:0950-0340    

DOI:10.1080/09500349014551991

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Picosecond time-resolved fluorescence spectroscopy and computer analysis procedures have been applied to study electronic energy transport in synthetic macromolecules. Second-harmonic generation and sum frequency mixing of actively mode-locked lasers provides tunable ultraviolet radiation for excitation of a wide range of vinyl aromatic polymers. Time-correlated single photon counting detection techniques enable the recording of fluorescence decay data with a time resolution of less than 50 ps and when combined with curve-resolution techniques based on principal factor analysis can provide insight into the heterogeneous fluorescence from polymers. The application of these techniques is described to examine energy transfer and excimer formation in solutions of poly(acenaphthalene), poly(2-naphthylmethacrylate) and films ofp-methyl styrene/acrylonitrile co-polymers.

ISSN:0950-0340    

DOI:10.1080/09500349014552001

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor