Tailored freeform optical surfaces

Abstract

Freeform optical surfaces embedded in three-dimensional space, without any symmetry, are tailored so as to solve the archetypal problem of illumination design: redistribute the radiation of a given small light source onto a given reference surface, thus achieving a desired irradiance distribution on that surface. The shape of the optical surface is found by solving a set of partial nonlinear differential equations. For most cases, a few topologically distinct solutions exist, given suitable boundary conditions.

Catadioptric freeform optical system design for LED off-axis road illumination applications

“…With emerging development of light emitting diode (LED) technologies, LEDs have been revolutionizing almost every aspect of modern life due to their incomparable advantages over traditional light sources, such as long life-time, high energy efficacy, friendliness to environment, good color rendering, and so on [1][2][3][4][5][6]. Undoubtedly there exist increasing needs for LED lighting in the field of road illumination.…”

Design of freeform optics

“…Tailoring method is for illumination design, the shape of the optical surface is obtained by solving a set of partial nonlinear differential equations according to the relationship among the incident light vector, the exit light vector, and the normal vector, and simultaneously according to the restrictions between the light source and the reference surface irradiance distribution [13].…”

“…In 2002, Ries and Muschaweck used freeform elements to attain a desired irradiance distrbution by using the tailoring method, as shown in Figure 2 [13].…”

“…B 1 is the incoming beam, and B 2 is the output beam, which consists of parallel light rays propagating in the same dirction as B 1 . The rays in B 1 are reflected by igure 2 Sketch of the setting and irradiance distribution [13]. reflector R 1 and then intercepted by reflector R 2 and at last reach the target suface (z = d) [25].…”

Analytic free-form lens design for imaging applications with high aspect ratio

“…Two main problems of non-imaging optics are efficient designs for illumination and solar concentration applications. Most non-imaging optics designs typically use few optical surfaces (often not more than two); advanced free-form optics design methods and solutions evolved over time, both for illumination applications (see, for example [2][3][4][5] ), and in concentration photovoltaics 6, 7 using the Simultaneous Multiple Surfaces (SMS) design method. The limited number of surfaces makes it possible to efficiently design highly aspheric or non-rotational symmetric free-form surfaces to address the system specifications.…”