Lenses can bend light and sound in almost any direction

When an optical fiber is bent by 90° or more, the light begins to leak away, posing a problem for fiber optics communications. But by using special lenses that can bend light by not only 90°, but also 180° (i.e., a U-turn) or 360° (i.e., a full loop), scientists may limit light leakage in optical fibers and overcome this problem, not to mention provide a useful material for many other applications. Recently, a team of scientists has theoretically investigated materials for achieving this kind of advanced light control, which could work equally well for sound waves.