The behaviour of evanescent waves under Lorentz transformations
Abstract
It is shown that transverse magnetic (TM) or transverse electric (TE) electromagnetic waves do not exist independently; i.e., under Lorentz transformations an original TM or TE evanescent mode is transformed into a linear combination of TM and TE evanescent modes that are out of phase by pi/2. The physical reason for this phenomenon is considered. An analysis is performed which indicates that there exist two linear combinations of TM and TE modes (the left- and right-hand circularly polarized modes) that remain the same in all systems. A proof is given, demonstrating that the projection of the angular momentum of a circularly polarized electromagnetic wave along the mean velocity of energy transport (i.e., helicity) can be reversed by a Lorentz transformation, even though this velocity is equal to the speed of light.
- Publication:
-
Nuovo Cimento Lettere
- Pub Date:
- December 1978
- Bibcode:
- 1978NCimL..23..547A
- Keywords:
-
- Circular Polarization;
- Electromagnetic Radiation;
- Evanescence;
- Lorentz Transformations;
- Transverse Waves;
- Wave Propagation;
- Angular Momentum;
- Electric Fields;
- Energy Transfer;
- Magnetic Fields;
- Phase Deviation;
- Propagation Velocity;
- Physics (General)