A mathematical method of finding a surface that focuses a finite size source has been developed. We show its use solving two particularly simple cases in which we compare the energy efficiency of the new surface to the classical elliptical cavities. In the examples given, the new designs are frequently advantageous.
© 1990 Optical Society of America
Rosa Weigand and Jose Manuel Guerra, "Envelope mirror: a new concept of focusing reflecting optics," Appl. Opt. 29, 4608-4613 (1990)