摘要:

We propose a realistic scheme to determine the quantum state of a single-mode cavity field even after it has started to decay due to the coupling with an environment. Although dissipation destroys quantum coherences, we show that at zero temperature enough information about the initial state remains, in an observable quantity, to allow the reconstruction of its Wigner function. 42.50.-p, 03.65.Bz, 42.50.Dv.

ISSN:0950-0340    

DOI:10.1080/09500349908231283

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

In this paper, we present the development and study of a photopolymerizable system composed of a xanthene dye (1) andN-methyldiethanolamine (MDEA) as photoinitiator with a monomer mixture of 2-hydroxyethyl metacrylate (HEMA) and pentaerithritol triacrylate (PETA). Diffraction yield, sensitivity and inhibition time of the formed gratings are the parameters studied when the materials have been irradiated with a wavelength of 514 nm and spatial frequency of 1000 lines mm−1. The best results obtained in the copolymerization were diffraction efficiencies over 40% with energetic exposures of 800 mJ cm−2, with a decrease of inhibition time when high concentrations of PETA were used.

ISSN:0950-0340    

DOI:10.1080/09500349908231284

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

In this paper, the properties of the demultiplexing module using the serialized nonlinear optical loop mirrors have been investigated. The noise of the demultiplexing output has been discussed in detail. The influences of the switches' settings on the noise and the properties of the bit error rate of each demultiplexing channel have also been investigated. It is shown that the power penalty of the demultiplexing module in a serial structure using the nonlinear optical loop mirrors is much lower than that in the parallel structure and it will be very small if the settings of the loop mirrors are carefully chosen

ISSN:0950-0340    

DOI:10.1080/09500349908231285

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

To study the interdiffusion effects in optical filters, we calculated the optical performances of diffused Fabry—Perot filters with several laws of index versus mixture for large interdiffusion and investigated the influences of the laws on the characteristics of filters. Some consequences of the calculated results for optical effects of interdiffusion are discussed. In this presentation we used a new calculation method by means of an equivalence between a general filter and an appropriate three-layer system at a wavelength. This equivalence might possibly be developed into a tool for treating optical thin films for some applications

ISSN:0950-0340    

DOI:10.1080/09500349908231286

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

Optical densities before bleaching and final Lin curves of planewave phase holograms recorded in Agfa—Gevaert 8E75HD emulsions were measured for various combinations of developers (AAC, Pyrogallol and Catechol) and bleaching agents (R-9 and EDTA). To characterize the processing, the square root of the diffraction efficiency of the processed holograms was related to the amplitude of the optical density modulation obtained at the development step. Characteristics of similar forms were obtained for all the processings, with significant differences in the slope and extent of the curves, so that sensitivity, linearity and dynamic range of the processes could be compared directly.

ISSN:0950-0340    

DOI:10.1080/09500349908231287

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The axial imaging properties of a confocal microscope using a single mode fibre as a detector are analysed. The axial response is calculated simply by performing an overlap integral in the back focal plane of the collector objective. The effects of axial misalignment of the fibre are investigated. The behaviour of the system has similarities with that of a confocal system with pinhole aperture and a finite Fresnel number geometry

ISSN:0950-0340    

DOI:10.1080/09500349908231288

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

We investigate the effects of spontaneous emission on two different laser-driven autoionization systems. We find that, under specific conditions, the relaxation decay processes can interfere destructively and lead to dark lines and spectral narrowing in the spontaneous emission spectra of these systems.

ISSN:0950-0340    

DOI:10.1080/09500349908231289

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

A scheme is proposed for preparing superpositions of many equidistant coherent states on a circle for the motion of an ion in an anisotropic two-dimensional trap, in which the ion is tightly bound in theydirection. In the scheme the ion is excited by one laser field in thexdirection and then by two laser fields propagating along thexandydirections alternately many times. Then a state-selective measurement on the ion is made, which collapses the vibrational motion to a coherent state superposition.

ISSN:0950-0340    

DOI:10.1080/09500349908231290

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

The semiclassical interaction of a two-level atom with a singlemode field, taking into account the atomic reaction onto the field, is considered. Analytical expressions for the field and atomic dynamics are found. An expansion of this solution in terms of the inverse of the field intensity is performed. To zeroth order, the classical Rabi solution is recovered, while first-order corrections give rise to a slow modulation of the atomic dipole, in agreement with a fully quantum model. The evolution of the atomic dipole is studied in the framework of the reducedQfunction, both in the semiclassical and quantum regimes. PACS 42.50.Dv — 03.65.-w.

ISSN:0950-0340    

DOI:10.1080/09500349908231291

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

We have measured the propagation losses of Cu—Na-ion-exchanged channel glass waveguides using both scattering and interferometric methods. In the first method, the waveguide was coated with a fluorescence film to enhance the scattered optical field along the channel waveguide which was then captured by a charge-coupled device camera. A straight line is adjusted to the intensity profile by the least-squares method, and the slope yields the attenuation coefficient. In the interferometric method, the temperature of the waveguides was changed and the intensity output was, measured. From contrast changes of waveguide's intensity output, the attenuation coefficient is calculated. Also, an analysis of the optical absorption of copper waveguides in the 200–1900 nm range to detect the copper oxidation state is presented.

ISSN:0950-0340    

DOI:10.1080/09500349908231292

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor