What is the light production mechanism inside a fluorescent tube?

What is the light production mechanism inside a fluorescent tube?

• A. Heated Phosphor Coating on the Inside of the Glass
• B. Mercury Vapor Ignition
• C. Filament Emission
• D. Inert Gas Luminescence

Answer: (A)

Fluorescent tubes produce light through fluorescence: an electric discharge excites mercury vapor inside the tube, which emits ultraviolet photons. Those UV photons are absorbed by a phosphor coating on the inner surface of the glass, and the phosphor re-emits the energy as visible light. The coating isn’t heated to emit light; it glows because it fluoresces when struck by UV radiation. The mercury discharge provides the UV energy, and the phosphor coating determines the visible color and quality of the light.

Fluorescent tubes produce light through fluorescence: an electric discharge excites mercury vapor inside the tube, which emits ultraviolet photons. Those UV photons are absorbed by a phosphor coating on the inner surface of the glass, and the phosphor re-emits the energy as visible light. The coating isn’t heated to emit light; it glows because it fluoresces when struck by UV radiation. The mercury discharge provides the UV energy, and the phosphor coating determines the visible color and quality of the light.