New efficient light guide for interior illumination

Experimental and theoretical studies of the recently patented prism light guide are described [L. A. Whitehead, U.S. Patent 4,260,220 (7 Apr. 1981)]. This device combines the total internal reflection of optical fibers with the low attenuation of air transmission of light. Since it can be moulded from acrylic plastic, the cost of the guide is low enough to make large-scale interior illumination with piped light feasible.