One of the principal goals in the design of photonic crystals is the engineering of band gaps and defect states. Here I describe the formation of topologically protected localized midgap states in systems with spatially distributed gain and loss. These states can be selectively amplified, which finds applications in the beam dynamics along a photonic lattice and in the lasing of quasi-one-dimensional photonic crystals.
© 2013 Optical Society of America
Original Manuscript: April 16, 2013
Manuscript Accepted: May 2, 2013
Published: May 27, 2013
Henning Schomerus, "Topologically protected midgap states in complex photonic lattices," Opt. Lett. 38, 1912-1914 (2013)