Nonimaging Optics

1 NONIMAGING OPTICAL SYSTEMS AND THEIR USES

1.1 NONIMAGING COLLECTORS

Nonimaging concentrators and illuminators have several actual and some potential applications, but it is best to explain the general concept of a nonimaging concentrator by highlighting one of its applications; its use of solar energy. The radiation power density received from the sun at the earth’s surface, often denoted by S, peaks at approximately 1kWm⁻², depending on many factors. If we attempt to collect this power by absorbing it on a perfect blackbody, the equilibrium temperature T of the blackbody will be given by¹

     (1.1)

where σ is the Stefan Boltzmann constant, ...