摘要:

Kerr nonlinearity, combined with feedback and diffraction, can be used to suppress phase distortions of laser beams and improve their collimation. No reference beam is required, nor need the beam re-traverse the distorting medium.

ISSN:0950-0340    

DOI:10.1080/09500349314551881

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A technique is described for the frequency modulation of a diode laser based on the optothermal effect. It is shown that it is possible to generate the frequency modulation with a minimum of power modulation. A frequency shift of approximately 1 GHz per mW of optothermal pump power was achieved in practice. The power modulation was about 7% of that observed when injection current modulation was used to generate a similar frequency shift. The optothermal frequency modulation technique was applied in a phase recovery scheme for a fibre interferometer based on pseudo-heterodyne signal processing.

ISSN:0950-0340    

DOI:10.1080/09500349314551891

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The concept for building a multistage switching network with optoelectronic components for several hundred parallel channels is investigated. The key components for an experiment are: laser arrays, microlens arrays, holographic optical permutation elements and a monolithic optoelectronic application specific integrated circuit with integrated photodetectors and electronic logic for switching. The demonstration presented in this contribution is a non-blocking and selfrouting shuffle exchange network implementing Batcher's sorting algorithm. It consists of three cascaded stages each having four parallel channels running at a clock rate of 1 MBit s−1. Scaling towards larger number of channels and higher overall data throughput is considered.

ISSN:0950-0340    

DOI:10.1080/09500349314551901

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The problem of the presence of a travelling electromagnetic wave in an inhomogeneous medium is addressed. An argument is presented in favour of the option that the Poynting vector determines whether the wave is travelling or not. A strict harmonic solution to the Maxwell equations in a plane stratified medium is shown not to be a travelling wave. This solution can be decomposed into two travelling fields which separately do not satisfy the Maxwell equations and which are identified as the transmitted and return fields. The direction of the Poynting vector for the transmitted field satisfies the generalized Snell's law. The reflectance of a layer of such a medium is calculated and shown to be zero for some incidence angles. Phases of the two travelling fields are considered and shown to be different from those of geometric optics.

ISSN:0950-0340    

DOI:10.1080/09500349314551911

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A general expression for the mutual coherence function of an electromagnetic field propagating in a fibre waveguide is presented by means of classical coherence formalism and the guided modes field representation. Moreover, this expression is applied to a limiting case of the fibre waveguide excitation by cross-spectrally pure, spatially coherent and quasi-monochromatic source with a symmetrical spectrum. In particular, the complex degree of both spatial and temporal coherence at the exit face of a two-mode, weakly-guiding, step-index fibre waveguide is discussed as a function of an exciting condition of guided modes, an intermodal dispersion and a temporal coherence of the source, respectively.

ISSN:0950-0340    

DOI:10.1080/09500349314551921

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

We discuss self-phase modulations and related transverse effects accompanying interaction of a light beam with a second harmonic radiation generated by it. Some experimental observations are explained by a simple perturbative approach. Numerical simulations provide a further insight into the nature of transverse self-effects in quadratically nonlinear media. An effectivex(3)-like behaviour of dispersive quadratically nonlinear media is discussed. Such feature may lead to important consequences for measurements of thex(3)tensor in complex nonlinear media.

ISSN:0950-0340    

DOI:10.1080/09500349314551931

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

ISSN:0950-0340    

DOI:10.1080/09500349314551941

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Entangled coherent states, with arbitrary weighting of the two product coherent states in the superposition, might be produced by incorporating an optical bistable device in a coupled cavity configuration. This scheme is contrasted with the entangled coherent states that arise due to interaction in an optical Kerr medium and produce only equally weighted entanglements. The entanglement is shown to occur, not between coherent states, but between states which closely approximate coherent states. An interaction which does produce entanglement between true coherent states is introduced but is shown to be unphysical.

ISSN:0950-0340    

DOI:10.1080/09500349314551951

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

We consider a three-level atom in any of its possible configurations, ladder, lambda or vee, which interacts with two classical, resonant, monochromatic electromagnetic fields. We suppose the levels

ISSN:0950-0340    

DOI:10.1080/09500349314551961

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The quantum dynamics of a coherently driven nonlinear oscillator are studied by solving the Schrödinger equation numerically. The results are used to examine the effect of increasingly strong driving on the mean number, squeezing, the second-order correlation function and the general behaviour of theQfunction. For comparison, the corresponding quantities for the classical Liouville dynamics are also computed. It is found that while the dynamics do maintain some quantum aspects as the strength of the driving is increased, the spectacular quantum features of the undriven nonlinear oscillator are in fact progressively lost.

ISSN:0950-0340    

DOI:10.1080/09500349314551971

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor