Diffraction by volume gratings with imaginary potentials

@article{Berry1998DiffractionBV,
  title={Diffraction by volume gratings with imaginary potentials},
  author={Michael V. Berry and D H J O’Dell},
  journal={Journal of Physics A},
  year={1998},
  volume={31},
  pages={2093-2101}
}
A medium described by an imaginary potential (or imaginary (refractive index) 2 ), that varies sinusoidally in one direction, acts as a volume grating for plane waves incident on it obliquely or normally. Two peculiar features are identified. First, if the potential is weak, so that there are only two significant diffracted beams near the Bragg angle, and three for normal incidence, diffraction is strongly affected by degeneracies of the non-Hermitian matrix generating the 'Bloch waves' in the… 

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References

SHOWING 1-10 OF 13 REFERENCES

Bloch wave degeneracies in systematic high energy electron diffraction

  • B. BuxtonM. Berry
  • Physics
    Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences
  • 1976
For the systematic diffraction of high energy electrons by a thin crystalline slab, we study the accidental degeneracies of the Bloch waves excited in the specimen by the incident beam. It is shown

The diffraction of light by high frequency sound waves: Part I.

4. Summary(a) A theory of the phenomenon of the diffraction of light by sound-waves of high frequency in a medium, discovered by Debye and Sears and Lucas and Biquard, is developed.(b) The formula

Between wave and particle-the semiclassical method for interpreting high-energy electron micrographs of crystals

Abstract The concepts of “semiclassical mechanics” are applied to the propagation of an electron beam through a crystal lattice. We obtain a variety of approximate descriptions which bridge the gap

The diffraction of light by high frequency sound waves: Part III

SummaryThe theory developed in Part I of this series of papers has been developed in this paper to find the Doppler effects in the diffraction components of light produced by the passage of light

High-Voltage Electron Microscopy

  • V. Cosslett
  • Materials Science, Chemistry
    Quarterly Reviews of Biophysics
  • 1969
Summary The main advantage of high voltage in electron microscopy is greater penetration. When using an aperture of optimum size the thickness of specimen that can be imaged increases almost linearly

Atom Waves in Crystals of Light.

TLDR
The experiments confirm that inside the light-field atoms fulfilling the Bragg condition form a standing matter wave pattern and observe anomalous transmission of atoms through resonant light fields.

Propriétés optiques des milieux solides et liquides soumis aux vibrations élastiques ultra sonores

Dans cet article sont decrites les principales proprietes optiques presentees par les milieux solides et liquides, soumis a des vibrations elastiques ultra sonores dont les frequences s'etagent de

The diffraction of light by ultrasound

The Crossing of Potential Surfaces.