by K. X. He, H. Abeleldayem, P. Chandra Sekhar, P. Venkateswarlu and M. C. George, Optics Communications, 81, #1-2, p. 101 (1 Feb 1991).
(I don't know how they managed to get ultrafast lasing from chinese tea, but ginseng had better be vigilant over its market share.) The precedent for this research was set at least as far back as the dark days just before Italian neorealist cinema; lab supplies were getting scarce: I understand that in Rome there was a study of proton scattering off of olive oil. (When you run out of protons, you can eat the target.)
My best guess is that the olive-oil study was done by Conversi, Pancini and Piccioni. Toward the end of WWII they worked in a cellar where they were hiding from the Germans.