On a partially color corrected illumination system

Abstract

In general lighting and some applications of automotive lighting, there are advanced requirements on light distributions. Illuminance should have a uniform course at different distances from the luminaire. As well disturbing colored borders of the distribution should be prevented. In the case of lens-based or catadioptric illumination systems, the light guidance takes place wholly or partly via refractive optical elements which leads to an inherent chromatic aberration. In the area of imaging optics, lenses with negative and positive powers made from different materials are combined for chromatic correction. If optical glasses are available for realization, systems with very good color correction can be designed. For cost reasons, however, classic concepts using optical glasses are excluded. Marketable materials are optical polymers, with low refractive index and midrange Abbe number. To understand the genesis of chromatic aberration, it is crucial to analyse every possible light path of the system. If a system has enough free parameters, one can optimize light paths due to their impact on chromatic aberration. Our goal is, to follow this approach concerning a purely refractive aspherical lens system without the usage of scattering structures.