摘要:

Transit times and eigenvalue equations found using ray-optics methods are compared with the exact wave-equation solution results. Geometric optics gives excellent accuracy for commonly used values of the dimensionless waveguide parameterV. Even when the effects of dispersion are included, the WKB condition gives exactly the same transit times as the more physically intuitive ray-optics technique.

ISSN:0030-3909    

DOI:10.1080/713819799

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Nous proposons une méthode simple permettant de déterminer si la relaxation de rotation avait le temps de se faire, dans le cas d'un composé organique en solution excité par un faisceau polarisé. Pour cela on compare les seuils d'émission laser dans deux cas: quand la polarisation de l'émission stimulée est parallèle à la polarisation de la source excitatrice et quand elle est perpendiculaire. La sélection de la polarisation de l'émission stimulée se fait avec un polariseur placé à l'intérieur de la cavité laser.

ISSN:0030-3909    

DOI:10.1080/713819803

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Calculation of distortion is developed by means of the plate diagram. This method is valid for all systems with one or two mirrors in the collimator and in the camera, and also for those with three or more mirrors, provided that their curvature centres, in each branch, are aligned. The problem of the slitimage curvature may also be solved by this method for spectrographs and monochromators which fulfil the condition established above. The results are checked with those obtained by K. P. Miyake with the light-path function for monochromators with off-axis parabolical mirrors.

ISSN:0030-3909    

DOI:10.1080/713819796

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

A vector Kirchoff, aperture-field analysis is employed to derive theorems relating (1) the far-field coherency matrix and the source mutual coherence tensor and (2) the far-field mutual coherence tensor and the coherency matrix elements. These theorems are derived for monochromatic sources and thermal radiation sources. The correspondence of these relations with previous results is noted. Sufficient requirements relating the components of the source generalized mutual coherence tensor are derived for propagation of completely polarized and unpolarized light. It is demonstrated that if the radiation source is cross-spectrally pure, the far-field intensity results from a convolution of spectral densities of the source-field's spatial and temporal fluctuations. The tensor analogue of the far-field van Cittert-Zernike theorem is found to be functionally identical with this classical result; however, strict incoherence of the source is not required for the validity of this theorem.

ISSN:0030-3909    

DOI:10.1080/713819797

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

We have theoretically investigated the problem of electromagnetic diffraction by a wide-angle spherical mirror receiving obliquely incident plane waves of linearly polarized monochromatic radiation. The Debye-Picht- Luneburg-Wolf integral representation of the diffracted field has been applied to determine the electromagnetic fields in the caustic region of the mirror. The direction cosines of the reflected rays were first calculated through the boundary conditions for a perfect conductor. The elementary solid angle for the reflected ray-cone was next reduced to a very simple and exact expression involving the obliquity σ of the incident beam. Two cases of polarization of the incident wave have been considered, namely, (1) with the field parallel and (2) perpendicular to the meridional plane of incidence. Explicit integral expressions for the field components in these two cases, have been obtained as functions of the obliquity σ. It has been shown that the diffracted field in the meridional plane of incidence can be decomposed into TM and TE modes. It has also been found that there exists a strong longitudinal field on the oblique axis of incidence, unlike in the case of normal incidence where the axial field is purely transverse. Finally, for small obliquities of the incident beam and observation in the meridional plane of incidence, simple formal expansions of the field have been obtained in terms of integrals involving Bessel functions.

ISSN:0030-3909    

DOI:10.1080/713819802

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/713819804

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/713819805

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/716099445a

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/713819798

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor