Green laser beam
A green laser beam crosses three glasses filled with canola oil, water and extra virgin olive oil. The oils modify energetic photons (green) to photons at lower energies: orange for canola oil, and red for olive oil; in an effect called fluorescence. However, the beam is so intense that you can see the green color as the laser passes through the glass of water, which is not fluorescent. [Second Place 2014 After Image photo contest.]
—Vicente Torres-Zúñiga, Universidad Nacional Autonoma de Mexico