Method for Dispersing Light Using Multilayered Structures

Stanford researchers have invented a novel method and device for separating light of differing wavelengths. This method uses a very simple and compact multilayer dielectric structure having high angular dispersion at certain wavelengths and angles of incidence. The structure is composed of alternating layers of dielectric materials of different refractive indices, and is designed to operate just outside the main reflection. In this region, there is strong group velocity dispersion, causing different wavelength of light to travel at different angles through the dielectric stack. As a consequence, different wavelength components of a polychromatic beam are separated as they pass through the device. This device can also operate as a multiplexer by simply reversing the direction of the light.