Anamorphic concentration of solar radiation beyond the one-dimensional thermodynamic limit

We propose and demonstrate a new scheme for anamorphic concentration of a b ig (40 cm x 40 cm) diffuse light source to achieve an extremely high concen tration in one lateral direction at the expense of that in the other direct ion, to preserve the total (two-dimensional) optical brightness. Such anamo rphic concentration is achieved by a combination of two conventional two-di mensional concentrators and a properly designed retroreflector array. Our e xperiments in search of a diffuse white-light source with properties compar able with those of solar radiation have yielded 28-fold improvement of the one-dimensional concentration ratio compared with those of conventional con centrators and 14-fold improvement compared with the one-dimensional thermo dynamic limit. (C) 2000 Optical Society of America OCIS codes: 080.2740, 22 0.1770, 230.6080, 350.6050.