Science in the Kitchen 2: Jello lasers

Last year my physical chemistry students and I attempted to design and build a dye laser from scratch. This is both easier and harder than you think. Several papers and an excellent web site provide background information and plans, but a good deal of patience is required to achieve an actual laser pulse. Limited time led to limited success for us.

Lots of different dyes will lase and you see the occasional reference on the web to Jello and whiskey lasers. These sound like urban legends, but in fact are not. Arthur Schawlow, who shared the Nobel Prize in physics in 1981 with Townes for building the laser, shows you can make Knox gelatin lase. See "Laser Action of Dyes in Gelatin", T. W. Hansch, M. Pernier, A. L. Schawlow, IEEE Journal of Quantum Electronics, January 1971, pp. 45-6. Interestingly, the longevity of the laser improves if you jiggle it.

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Science in the Kitchen 1: Extracting DNA