PERFORMANCE LIMITATIONS OF ROTATIONALLY SYMMETRICAL NONIMAGING DEVICES

An upper limit on concentration for any optical device has previously been derived from the conservation of etendue. In this contribution we derive more stringent upper limits for the efficiency and the concent ration of rotationally symmetric optical devices that are a consequenc e of skewness conservation. If the desired source and target have diff erent skewness distributions, then losses or dilution or both will lim it the performance of the optical system. We calculate the limiting cu rve of efficiency versus concentration and provide a design example th at is virtually at this limit. We conjecture that even rotationally sy mmetric problems may benefit from asymmetric optical systems. (C) 1997 Optical Society of America.