What is Filament

What is Filament

Filament is the thin wire or coil found inside a light bulb that emits light when heated. Typically made of tungsten, which has a high melting temperature, the filament is the main component that enables incandescent lamps to produce visible light.

To prevent combustion, the filament is housed in a sealed, oxygen-free chamber. In the early days of light bulbs, the air was removed to create a near vacuum, but this caused the tungsten atoms to evaporate, leading to a shortened lifespan of the bulb. To address this issue, modern light bulbs now use inert gases, such as argon, to reduce the loss of tungsten atoms. When a tungsten atom evaporates, it is likely to collide with an argon atom and bounce back towards the filament, rejoining the solid structure. This prevents the elements from combining in a combustion reaction.

Incandescent light bulbs, which rely on filaments, are not as energy-efficient as other lighting technologies. They waste a significant amount of energy by emitting most of it in the form of heat-carrying infrared light photons, with only about 10 percent of the light falling within the visible spectrum. As a result, incandescent bulbs have been gradually replaced by more advanced and energy-efficient alternatives like fluorescent lamps and LEDs.