Image Guidance of Pleural Biopsies: Are Electromagnetic Waves Superior to Sound Waves?

Diffraction of Electromagnetic Waves

The general method to obtain solutions of the Maxwellian equations from scalar representatives is developed and applied to the diffraction of electromagnetic waves. Kirchhoff’s integral is modified to provide explicit expressions for these representatives. The respective integrals are then evaluated using the method of stationary phase in two dimensions. Hitherto unknown formulae for the polari...

Dust-Acoustic Waves: Visible Sound Waves

A historical overview of some of the early theoretical and experimental work on dust acoustic waves is given. The basic physics of the dust acoustic wave and some of the theoretical refinements that have been made, including the effects of collisions, plasma absorption, dust charge fluctuations, particle drifts and strong coupling effects are discussed. Some recent experimental findings and out...

Phs 342 : Electromagnetic Waves

Cosmic sound waves rule

© 2008 American Institute of Physics, S-0031-9228-0804-010-6 Relativistic sound waves raced through the hot plasma that filled the universe for its first 380 000 years. That sound left an imprint that is still discernible in the cosmic microwave background and also in the large-scale distribution of galaxies. Measurements of the sound waves manifested in the CMB, coupled with a detailed underst...

Time reversal of electromagnetic waves.

We report the first experimental demonstration of time-reversal focusing with electromagnetic waves. An antenna transmits a 1-micros electromagnetic pulse at a central frequency of 2.45 GHz in a high-Q cavity. Another antenna records the strongly reverberated signal. The time-reversed wave is built and transmitted back by the same antenna acting now as a time-reversal mirror. The wave is found ...