Here’s a neat project from a few years ago: Nyle Steiner of sparkbangbuzz built a Simple Homemade T.E.A. Laser using some pieces of scrap aluminum and a moderately high voltage power supply. He writes:
I used to tell people “There is no such thing a true home made laser. There is always a requirement for exotic parts that can only be obtained from a laser manufacturer, and – or there is the requirement to perform exotic high vacuum, glass blowing and gas mixing processes. This would defeat much of the satisfaction of building your own laser.” When I read about TEA lasers recently though, that all changed. Here is a laser that is built from aluminum foil, a dielectric and some pieces of aluminum. It is amazing to think of a laser project where a simple 4 to 6 KV DC power supply is the most elaborate component.
Amazing, indeed! Now, where did that kV DC power supply go? [thanks, Ed!]