WATERFALL LASERS

Laser concepts can be applied to a broad range of physical phenomena. One of the closest parallels occurs with the fluttering oscillations t hat are sometimes observed in the falling sheets of water associated w ith fountains, dams, and natural waterfalls. In many respects these fl uid feedback oscillations are similar to the electromagnetic modes of typical lasers, and recognition of this similarity led to the interpre tation of the waterfall behavior. Gain profiles for the waterfall osci llations are developed, and the relationship of experimental waterfall data to the laser-like models is considered in detail. (C) 1997 Ameri can Institute of Physics.