Mid-band zero group velocity in slow light structures

摘要

We study theoretically slow light structures exhibiting zero group velocity in middle of the Brillouin zone. We find that in order to exhibit a mid-band group velocity point in its dispersion relation, a slow-light structure must possess two distinct optical paths supporting counter-propagating power flows. This is in contrast to conventional slow-light structures which exhibit zero group velocity only at the edge of their Brillouin zone, which indicates the emergence of a standing wave.