A Multiplexing Stream
The beams from three different wavelength laser pointers pass through a tank of water, and exit into a single water stream. Once in the stream, the beams can be seen reflecting at the water-air interface, as a result of total internal reflection, and following the curved path of the water stream. [Honorable mention 2017 After Image photo contest.]
—Aongus McCarthy, Heriot-Watt University