The light from a glow stick is pretty diffuse. Has anyone invented a flashlight like enclosure to focus it?
Some kind of glow stick flashlight, concentrating the light into a single beam, would be cool.
The light does not contain sufficient energy to warrant focussing.
For “entertainment” purposes, why would you want to, and for safety purposes, the larger area of the stick is also much more visible than concentrating it into a “narrow” beam (which won’t be any brighter).
They also emit their light omnidirectionally, at least in the plane at right angles from the stick, which is a great thing for both purposes.
Light Sticks – Cool Halloween Science