Researchers from the Universitat Politècnica de Catalunya and members of the GenIUL R&D team, used PAUL instruments (blue and red light) to show the photodynamic properties of eucalyptus (Eucalyptus globulus), clove (Eugenia caryophyllata), and thyme (Thymus vulgaris) essential oils against bacteria and yeast.

http://www.sciencedirect.com/science/article/pii/S1572100016301363