From Blue to Green
A blue/UV laser pointer was coupled into the handle of a cup, which guides the light and feeds it into a fluorescing liquid that lights up in green colors. The surrounding lab environment was darkened completely to highlight the effect. The image was taken in the lab at Leibniz-IPHT Jena. [Winning entry, 2018 After Image photo contest.]
—Tobias Tieß, Leibniz-IPHT, Germany