Design of freeform reflector array for oblique illumination in general lighting

Abstract

Downloaded From: http://opticalengineering.spiedigitallibrary.org/ on 08/15/2015 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspxAbstract. With increasing concerns about light pollution and energy waste in general lighting, efficient and effective lighting techniques have become imperative. We present the design of a kind of dedicated oblique illumination (OI) system to solve the problems of light pollution and the waste of energy in general lighting. The OI system consists of an extended (actual) light source, a collimator, and a freeform reflector array. Two different layouts of the OI system are proposed for different lighting situations, and design models of the two layouts are also given by use of the Monge-Ampère equation method. Two typical lighting situations, street lighting and advertising board lighting, are given here to illustrate the proposed OI system, and characteristics of the OI system are explored. The results show the light distribution is well controlled with a pretty good optical performance and the OI system has a large tolerance to the change of intensity distribution of the light source and to the size of the light source. Downloaded From: http://opticalengineering.spiedigitallibrary.org/ on 08/15/2015 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx Optical Engineering 065103-2 June 2015 • Vol. 54(6) Chen and Wu: Design of freeform reflector array for oblique illumination in general lighting Downloaded From: http://opticalengineering.spiedigitallibrary.org/ on 08/15/2015 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx Optical Engineering 065103-7 June 2015 • Vol. 54(6) Chen and Wu: Design of freeform reflector array for oblique illumination in general lighting Downloaded From: http://opticalengineering.spiedigitallibrary.org/ on 08/15/2015 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx Optical Engineering 065103-8 June 2015 • Vol. 54(6) Chen and Wu: Design of freeform reflector array for oblique illumination in general lighting Downloaded From: http://opticalengineering.spiedigitallibrary.org/ on 08/15/2015 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx Optical Engineering 065103-10 June 2015 • Vol. 54(6) Chen and Wu: Design of freeform reflector array for oblique illumination in general lighting Downloaded From: http://opticalengineering.spiedigitallibrary.org/ on 08/15/2015 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx

Making photocatalysts screenable – a milliscale multi-batch screening photoreactor as extension for the modular photoreactor

“…[16][17][18] Therefore, engineering concepts such as geometrical overlapping and arrangement of light sources, usage of multiple-curvature lenses or reflector concepts can be deployed to increase the uniformity of illumination across the screening area. [19][20][21][22][23] Ensuring uniform illumination over larger areas depicts a tremendous challenge. 24,25 Since the activity of a photochemical system scales in a linear fashion with the absorbed photon flux within the photon limited regime of a photoreaction, screening setups must be at least sufficiently characterized from a photonic standpoint to take irradiation inhomogeneities into account.…”

“…The application of freeform reflectors is one suited concept for engineering irradiance uniformity over relatively large areas. 23,53,54 Commercially available materials such as PTFE offer good diffuse reflectivity and are therefore particularly suited as reflector materials. 55 In addition, even relatively thin PTFE sheets already assure high and even reflectivity over the UV/vis range (see Fig.…”