Using Lorentz reciprocity and power conservation, we prove that the extinction cross section of an arbitrarily shaped scatterer is always the same when illuminated from opposite directions and with the same polarization. For lossless and passive objects, this finding implies identical scattering cross sections for opposite excitations, with relevant implications on cloaking designs and scattering suppression schemes. This scattering symmetry can be broken by introducing absorption into the system, providing a path toward large scattering asymmetries when combined with Fano interference.
© 2014 Optical Society of America
Original Manuscript: April 29, 2014
Revised Manuscript: May 29, 2014
Manuscript Accepted: May 30, 2014
Published: June 30, 2014
Dimitrios L. Sounas and Andrea Alù, "Extinction symmetry for reciprocal objects and its implications on cloaking and scattering manipulation," Opt. Lett. 39, 4053-4056 (2014)