The most well-known application of fluorescence is the fluorescent lamp, which consists of a glass tube filled with a gas and lined with a fluorescent material. Electricity is made to flow through the gas, causing it to radiate. Often mercury vapor, which radiates in the violet and ultraviolet, is used. This radiation strikes the coating, causing it to fluoresce visible light. Because the fluorescence process is used, the fluorescent lamp is more efficient and generates less heat than an incandescent bulb.
Resonance fluorescence can be used as a laboratory technique for analyzing different phenomena such as the gas flow in a wind tunnel. Art forgeries can be detected by observing the fluorescence of a painting illuminated with ultraviolet light. Painting medium will fluoresce when first applied, then diminish as time passes. In this way paintings that are apparently old, but are really recent forgeries, can be discovered.