In OPN's December “Optics in 2015” review of interesting research conducted in the previous year, a team led by Rajesh Menon of the University of Utah (USA) describe their use of “digital metamaterials” to develop tiny, power-efficient devices for optical communication. The first video below shows data from what the team describes as the smallest polarization beam splitter (PBS) thus far—a mere mere 2.4 microns in width. The second video shows an integrated mode-converting polarization beam splitter (PBS) only four microns in width.