Molding the flow of light

A new class of materials, called photonic crystals, affects a photon's properties in much the some way that a semiconductor affects an electron's properties. The ability to mold and guide light leads naturally to novel applications in several fields, including optoelectronics and telecommunications. The authors present an introductory survey of the basic concepts and ideas, including results for never before possible photon phenomena. The paper considers how computer calculations and design play particularly important and complementary roles in experimental investigations of photonic crystals.