摘要:

In this letter the first performance of tunable solid-state ultraviolet laser, based on 5d-4f transitions of Ce3+ions in a colquiriite LiCaAlF6single crystal, is reported. Our findings hold promise for devising a tunable u.v. all-solid-state laser pumped by the fourth harmonic radiation of any commercially available Nd laser.

ISSN:0950-0340    

DOI:10.1080/09500349314550011

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

It is shown that the static dipole-dipole interaction influences the steady-state collective mean atomic inversion for two-atom resonance fluorescence in a broadband squeezed vacuum.

ISSN:0950-0340    

DOI:10.1080/09500349314550021

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

An exact method of the evaluation of the effects of the finite spatial resolution of the recording material on the reconstructed holographic image is presented in this paper. The method is based on substitution of the amplitude transfer function (the square root of the modulation transfer function) of the recording material modelled by analytical function to the double Fresnel-Kirchhoff integral. Numerical calculations have been carried out for microline objects in three recording geometries, including one with a tilted object plane.

ISSN:0950-0340    

DOI:10.1080/09500349314550031

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

In the context of the nonlinear interaction of counterpropagating light beams, we demonstrate the unrealistic symmetries that arise in the simulation of spontaneous pattern formation when using square computational grids. We have formulated a generalization of the split-step Fourier method which allows for non-orthogonal spatial grids. Implementation is shown to be simple and to entail negligible computational overheads. Results for two-dimensional Gaussian and extended cosine-bell input beam profiles are presented.

ISSN:0950-0340    

DOI:10.1080/09500349314550041

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A fundamental theorem of quantum cryptography is proved which states the conditions under which an eavesdropper can be detected. A corollary of this theorem is that any two-alphabet quantum cryptography scheme must sacrifice some of the potential key data to guarantee security.

ISSN:0950-0340    

DOI:10.1080/09500349314550051

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Linear couplers with asymmetric gain or loss are considered. The resonance, which exists between the mean differential gain coefficient and the local mode-coupling coefficient, changes the effective beat length and leads to complete optical switching in a many beat length device.

ISSN:0950-0340    

DOI:10.1080/09500349314550061

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

In this paper we investigate theoretically the behaviour of a quantum optical oscillator, consisting of two-level atoms strongly coupled to a cavity mode, in the optical domain. In contrast with the usual laser theory, we include explicitly the effects of atomic spontaneous emission and of cavity decay in the interaction of the atoms with the cavity field, using a quantum mechanical master equation approach. It is shown that such an oscillator produces sub-Poissonian light with a large degree of noise reduction even for the case when the atom–field coupling constant is only marginally larger than the spontaneous decay rate.

ISSN:0950-0340    

DOI:10.1080/09500349314550071

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Wavelength demultiplexing of the signal and reference arms in a pressure sensor determining the pressure from the diaphragm curvature is applied. Using one optical fibre for both signal and reference arms gives a measurement accuracy better than 2% of full scale for additional fibre losses of up to 8 dB. The sensor system has a useful dynamic range of more than 25 dB.

ISSN:0950-0340    

DOI:10.1080/09500349314550081

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The phase properties of the squeezed number states have been studied from the lower order to the higher order via the measured phase operators (MPO) introduced by Barnett and Pegg and compared with those obtained via the Hermitian and Susskind-Glogower phase operators. We have found many new, interesting results. For the lower order, the phase fluctuations of the MPO are exactly independent of the photon numbern. For the higher order, the corresponding fluctuations are a decreasing function ofn.

ISSN:0950-0340    

DOI:10.1080/09500349314550091

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Free space propagation of an array of optical vortices nested in a smooth (Gaussian) beam is studied in the paraxial regime. It is found that when the vortices have all the same charge, their relative positions, as well as their positions within the host beam are invariant upon propagation. The array simply expands or contracts with the host beam and rotates rigidly. Vortices of opposite charges, in contrast, attract each other. Pairs can collide and annihilate. As an illustration, numerical simulation is used to compare the propagation of a pair of vortices of equal charges with that of a pair of opposite charges.

ISSN:0950-0340    

DOI:10.1080/09500349314550101

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor