ISSN:0950-0340    

DOI:10.1080/09500348714551431

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

ISSN:0950-0340    

DOI:10.1080/09500348714551441

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

A theoretical basis for the use of fluorescent emissions from highlying excited states as a diagnostic of excimer-laser discharge character is derived. Experimental tests have been used to place confidence limits on the approximate theory used. The greater understanding obtained has permitted indirect observation of discharge constriction using this diagnostic.

ISSN:0950-0340    

DOI:10.1080/09500348714551451

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

In this paper, the process of image formation in electron holography is calculated based on a simplified model. The results have shown that the extension of the electron-beam source can cause a decrease in the electron-holography resolution. On the other hand, the unfavourable effects due to source extension can be eliminated by using the electron-image holography method.

ISSN:0950-0340    

DOI:10.1080/09500348714551461

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

We derive conditions for the physical realizability of polarization matrices characterizing passive systems or scattering media. By physically realizable, we mean that 0 ⩽ g ⩽ 1 whereg≡ (output intensity/input intensity). Using the singular-value decomposition of an arbitrary 2 × 2 complex-valued matrix, we prove that a Jones matrixTJis physically realizable if 0 ⩽ detTJ+TJ⩽ 1. Consequently singular Jones matrices (i.e. detTJ= 0) completely extinguish the output intensity irrespective of the input intensity becauseg≡ 0. Corresponding results are obtained for Mueller-Jones matrices (the 4 × 4 real-valued matrices which are the four-dimensional representations of the two-dimensional 2 × 2 complex-valued Jones matrices). We also study the problem for general Mueller matrices; however because of their phenomenological character they do not admit of such criteria as do the Jones and Mueller-Jones matrices. This is becausegnow depends upon the matrix elements of the Mueller matrix and the input Stokes parameters; whereas for the Jones and Mueller-Jones matrices,gonly depends upon the matrix elements. Finally we study the problem of relating the input and output mean randomness.

ISSN:0950-0340    

DOI:10.1080/09500348714551471

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The problem of cavity radiation and its detection is reviewed and in particular the evolution equation of Scully and Lamb is studied with special reference to coarse-graining. It is shown that the resulting evolution equation corresponds to that of a Markov process representing the cavity population. The approximations corresponding to oscillations below and above threshold reduce the process to a branching process with immigration. The effect of the detector is also studied and the photocount statistics are shown to correspond to those of an emigration process superposed on the branching process. The identification of the evolution as a branching process is shown to result in considerable simplicity and ease in the determination of the statistical characteristics of the cavity population. In particular the Shepherd model is identified as a special case; a complex situation like the multi-mode oscillation is also identified and the corresponding statistical characteristics obtained.

ISSN:0950-0340    

DOI:10.1080/09500348714551481

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The structure and properties of optical radiation are considered in terms of inhomogeneous waves propagating in isotropic absorbing media. Within the framework of the proposed representation, it is shown that the optical properties of inhomogeneous waves can be completely defined by three independent variables related to the degree of inhomogeneity of the wave, together with the ellipticity of theEandHcomponents of the wave field. The values of these variables cannot be chosen completely arbitrarily. In a geometrical interpretation we consider these variables to be restricted to a three-dimensional region demarked by a ‘boundary wave surface’. The topology of this boundary wave surface and the possible types of inhomogeneous wave are investigated, and invariant relations are revealed. Simple and compact relations describing inhomogeneous waves are proposed.

ISSN:0950-0340    

DOI:10.1080/09500348714551491

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The basic properties of the autocorrelation function of a bar code system are studied with special emphasis placed on the method of improving the contrast of the main peak above the rest of the correlation signal. The classification of the different types of bar codes is made in accordance with their optimum performance in light utilization, the rate of increase of the main peak and the noise characteristics. These factors are important technical data in the applications of the bar codes to precision positioning.

ISSN:0950-0340    

DOI:10.1080/09500348714551501

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

The power and wavelength of the output radiation and the final energy distribution of the electron beam of a free-electron-laser oscillator are calculated at the steady-state condition in which the gain per pass is set to be equal to the round-trip loss inside the cavity. The effect of the constant axial magnetic field on the output wavelength is also discussed, which suggests a practical way to achieve a fine tuning of the output frequency of a free-electron-laser oscillator. The Stanford experimental measurements of a free-electron oscillator at the steady state are used to test the theory and show good agreement.

ISSN:0950-0340    

DOI:10.1080/09500348714551511

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor

摘要:

We present results from experiments on the ageing influence of laser-induced damage of evaporated Ta2O5quarter-wave single-layer films and coating systems of Ta2O5-SiO2at λ = 1060 nm. With Ta2O5films emphasis is placed on the correlation between increase in damage threshold and decrease in absorption with the storage time.

ISSN:0950-0340    

DOI:10.1080/09500348714551521

出版商:Taylor & Francis Group    

年代:1987

数据来源: Taylor