CONCENTRATING AND COLLECTING OPTICAL SYSTEM USING CONCAVE TOROIDAL REFLECTORS

摘要

An electromagnetic radiation source (SO), such as an arc lamp, is located at a point displaced from the optical axis of a concave toroidal reflecting surfa ce (M1). The concave primary reflector (M1) focuses the radiation from the sour ce (SO) at an off-axis image point that is displaced from the optical axis. The use of a toroidal reflecting surface enhances the collection efficiency into a small target (T), such as an optical fiber, relative to a spherical reflecti ng surface by substantially reducing aberrations caused by the off-axis geometr y. A second concave reflector (M2) is placed opposite to the first reflector (M 1) to enhance further the total flux collected by a small target (T). In accordance with one embodiment, the present invention is directed to devices in which the square of the off-axis distance divided by the radius of curvature is equal to or less than the extent of the source of electromagnet ic radiation (yo2/r<so).