How does a CFL bulb work?
Compact fluorescent lamps are arc discharge lamps that produce light by exciting mercury vapor. Electricity is applied to the electrode at the end of the lamp where it excites the mercury. Once the mercury is excited, it carries the electrical current via an arc across the lamp to the other end. The excited mercury produces most of its energy in the ultraviolet (UV) range. The UV energy stretching across the lamp activates a phosphor, the white coating on the inside of the bulb, which emits visible light.
