Freeform lens generation for quasi-far-field successive illumination targets
| Autor: | Simon Thibault, Zhenfeng Zhuang |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Surface (mathematics)
business.industry Computer science ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION Irradiance Near and far field 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials law.invention 010309 optics Lens (optics) Set (abstract data type) Optics law 0103 physical sciences Range (statistics) Point (geometry) Electrical and Electronic Engineering Physical and Theoretical Chemistry 0210 nano-technology business ComputingMethodologies_COMPUTERGRAPHICS |
| Zdroj: | Optics Communications. 418:65-72 |
| ISSN: | 0030-4018 |
| Popis: | A predefined mapping to tailor one or more freeform surfaces is employed to build a freeform illumination system. The emergent rays from the light source corresponding to the prescribed target mesh for a pre-determined lighting distance are mapped by a point-to-point algorithm with respect to the freeform optics, which involves limiting design flexibility. To tackle the problem of design limitation and find the optimum design results, a freeform lens is exploited to produce the desired rectangular illumination distribution at successive target planes at quasi-far-field lighting distances. It is generated using numerical solutions to find out an initial starting point, and an appropriate approach to obtain variables for parameterization of the freeform surface is introduced. The relative standard deviation, which is a useful figure of merit for the analysis, is set up as merit function with respect to illumination non-uniformity at the successive sampled target planes. Therefore, the irradiance distribution in terms of the specific lighting distance range can be ensured by the proposed scheme. A design example of a freeform illumination system, composed of a spherical surface and a freeform surface, is given to produce desired irradiance distribution within the lighting distance range. An optical performance with low non-uniformity and high efficiency is achieved. Compared with the conventional approach, the uniformity of the sampled targets is dramatically enhanced; meanwhile, a design result with a large tolerance of LED size is offered. |
| Databáze: | OpenAIRE |
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