摘要:

Phase gradients present in an optical wavefield with constant intensity can be measured using only two identical gratings and one or more photo-detectors. For Ronchi rulings, the detector output depends linearly on the spatial derivative of the optical phase perpendicular to the grating lines. The usefulness of this set-up combined with on-line data processing is demonstrated for the study of a turbulent random phase screen.

ISSN:0030-3909    

DOI:10.1080/713820787

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A recent paper by J. J. Stamnes [1982, Optica Acta,29, 823] included a misleading discussion of the role of catastrophe theory in diffraction physics. Most notably, the singularity at the shadow boundary for edge-diffraction integrals was incorrectly called a catastrophe. The true relevance of catastrophe theory is discussed, with particular reference to edge diffraction.

ISSN:0030-3909    

DOI:10.1080/713820779

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/713820776

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/713820778

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/716099585

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/713820782

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/713820774

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0030-3909    

DOI:10.1080/713820785

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The metallic diffraction grating problem has been solved for P-polarization using a conformal mapping and the surface impedance boundary condition. The method is used to calculate the electromagnetic fields diffracted by a grating having a cycloidal groove shape. The numerical results are compared with those obtained using the direct differential formalism. For low conductivities the coincidence between both results is only qualitative, whereas there exists a zone for greater conductivities where the differences are smaller than 0·;005. For even greater conductivities the approximated boundary condition employed holds more exactly, but the comparison is not possible because the direct differential method involves numerical problems.

ISSN:0030-3909    

DOI:10.1080/713820790

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

For gratings having an arbitrary symmetric profile, we prove that when the period becomes much finer than the wavelength the grating becomes equivalent to a graded uniaxial layer. We show for one polarization that this quasi-static equivalence holds when the ratio of wavelength to grating period exceeds 40. We also present a simple physical model which explains the anisotropic nature of the equivalent layer. We take the case of a finely-textured copper surface, and show that it can be a good selective absorber for polarized light, but that its performance in unpolarized light is much less satisfactory.

ISSN:0030-3909    

DOI:10.1080/713820783

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor