Current developments in photonics use new materials to combine light conversion and light scattering. High power density, small dimensions and the mutual influence of conversion and scattering make a simulation of light conversion and light scattering impossible. Spectrally resolved scattered light measurements are a crucial prerequisite for the development of even more efficient light sources.

The standard measurement method for determining the BSDF (bidirectional scattering distribution function) / BRDF (bidirectional reflectance distribution function) is goniophotometry. The sample is mounted on a specimen fixture. Lighting and a detector are positioned relatively around the sample. Scattered light goniophotometers have a complex and expensive setup and are slow. In the project, a new, fast and cost-effective solution for scattered light measurement was developed. Thus, a new module is added to the proven opsira robotic goniophotometer (robogonio) to enable fast and cost-effective spectrally resolved scattered light measurements.

The robogonio is a very versatile system to realize the relative solid angles and distances between the DUT (luminaire, lamp) and the detector system required for photometric measurements in a very wide range.

The aim of the project was to develop an additional module for the robogonio, which realizes the need of at least 2 more axes without an additional device, but as an additional "claw" attached to the robogonio.  

The new robogonio BSDF will be presented during the next Light+Building Tade Show from October 2nd to 6th, 2022 in Frankfurt/Main in Germany, opsira Stand F70 – Hall 8.0.

This Project is supported by the Federal Ministry for Economic Affairs and Climate Action (BMWK) on the basis of a decision by the German Bundestag.