Sajeev John’s pioneering research on using photonic crystals to capture and process light has enabled the unprecedented control of light flow in optical microchips. Dr. John has provided the framework for using photonic crystals to direct light within the photonic band gap, much like traditional semiconductors process electrons in electronic chips. Dr. John’s light-capturing materials prevent light from diffracting, scattering, and ultimately escaping a chip to allow for microscopic control of photons in an optical microchip. Photonic materials based on Dr. John’s work have found applications in optical communications, lighting technologies, and microstructured optical fibers used for endoscopic laser surgery. His theoretical models also show promise for high-efficiency solar energy harvesting, metallic photonic crystal filaments with laser-like light emission, and three-dimensional optical waveguide circuits for all-optical information processing.