Concentrating light in a volume as small as the wavelength itself is a challenge that is crucial for numerous applications. Researchers from AMOLF, TU Delft, and Cornell University in the U.S. have demonstrated a new way to focus light on an extremely small scale. Their method utilizes special properties of a photonic crystal and works for a broader spectrum of wavelengths than alternative methods. The researchers published their findings in Science Advances on April 18.