ABSTRACT

This chapter discusses the concept of flowline for nonimaging optical designs. All Lambertian radiators that subtend the same solid angle at a point, in the strict sense that they are bounded by the same cone, give the same vector flux at that point. The chapter discusses the geometry for calculating the vector flux for a luminous disk and describes a simplified method for calculating lines of flow. A mirror surface placed along lines of flow of the vector flux will not disturb the overall flow pattern under a certain condition. Since light rays are reversible, a way to construct a concentrator with maximum theoretical concentration is to place mirrors in the flowlines under conditions of detailed balance of the rays. The chapter also provides a discussion on generalized flowline concentrators with refractive components.