PhD graduate lays ground work for entirely new approach in optical design

Mathematician and TU/e PhD graduate Bart van Lith has created a whole new field of science by combining his mathematical and physical insights. His PhD study has generated a new, innovative approach that opened a whole new field in computational illumination optics. Last week he was awarded his PhD with distinction for his work at the department of Mathematics and Computer Science.

The motivation for this PhD research project, which was part of the Flagship Lighting in the Intelligent Lighting Institute, came from a classical problem in illumination optics: in several lighting applications (e.g. LEDs) of different colors are used. To create a uniform output, the lights need to be mixed. Up to now these computations were made by using ray-tracing techniques; a technique used to predict the path of light rays into, through, and out of e.g. a light guide.

However, Van Lith concluded in his research project that ray-tracing techniques have shortcomings. That is why he came up with an innovative approach using the transport of energy as the physical model instead of the commonly used ray-tracing approach. The advantage of this method is that it gives the energy distribution at all positions in the system immediately and within a shorter computational time and/or with a higher accuracy than ray tracing.

Real impact
Van Lith’s approach, extended to 3D geometries, opens up the opportunities to address a whole series of new applications and will strongly enhance the future tool set of optical designers in industry. It will allow them, among others, to design optical systems in less time, design new optical components, optimize optical systems with real sources automatically, and do system analysis using the energy distribution in phase space.

According to his supervisors Wilbert IJzerman and Jan ten Thije Boonkkamp, Van Lith’s work is impressive. Not only did he lay the ground work for an entirely new approach in optical design for illumination purposes. His dissertation also contains an extensive description of innovative ways to continue this research which will allow to extend the research in the field of computational illumination optics in the coming years.

Van Lith graduated at TU Eindhoven in both Applied Physics, and Industrial and Applied Mathematics. His final work obtained a grade 10 in Mathematics and resulted already in one publication from his hand. The ‘distinction’ that has been given to his dissertation ‘Principles of computational illumination optics’ is quite extraordinary. Only around five percent of all dissertations qualify, which is around ten to fifteen a year.