Laboratory set-up for irradiation experiments including light sources (lasers, solar simulator), light detectors and detectors for O₂ and NO. We are using this for all light-activated experiments, using monochromatic or polychromatic or sun- imitative, well-stabilized light sources. The O₂ detector enables provide irradiation experiments under control of oxygen content. This is important in experiments leading singlet oxygen generation. The NO detector enables detection of releasing NO radicals for NO-photodonors.