Light is a slippery fellow. Stand in a darkened hallway and close a door to a lighted room: Light will sneak through any cracks—it doesn't want to be confined. "Typically, in free space, light will go everywhere," graduate student Chia Wei (Wade) Hsu says. "If you want to confine light, you usually need some special mechanism."
Last summer, Hsu demonstrated a new way to confine light on the surface of a photonic crystal slab. "We were the first ones to experimentally demonstrate this new way to confine light," says Hsu, a graduate student in physics who is conducting research under Marin Soljacic, a professor of physics as MIT.