Instrument extension by green laser source

<The gonio-photometer has been extended by a third light source. The 4mW laser diode has a peak emission at about 520nm. Focused on the sample, it allows for a minimized sampling aperture. This is of importance if small samples shall be characterized under oblique incident directions, or if the average BSDF of small regions on non-uniform samples shall be measured seperately. The new source would also allow to increase the directional resolution – however, its current configuration (without a spatial filter) is optimized for optical power rather than directional resolution.