In this work, the electric field emitted from a moving source, an electric point dipole, is analyzed for the purpose of illustrating the physics behind the Doppler effect. It is found that if the (translational) motion of the source is nonrelativistic, the Doppler effect is realized in two steps: the motion of the source first causes the dyadic Green function associated with the electric field to acquire an oscillation frequency in the far-field region of the source, and then the frequency leads to the Doppler effect. It is also demonstrated that the Doppler effect is observable only in the far-field region of the source.
© 2012 Optical Society of America
Original Manuscript: March 15, 2012
Revised Manuscript: June 14, 2012
Manuscript Accepted: June 15, 2012
Published: July 18, 2012
Wei Guo and Yildirim Aktas, "Reexamination of the Doppler effect through Maxwell’s equations," J. Opt. Soc. Am. A 29, 1568-1570 (2012)