Gas lasers are a type of laser that use a gas as the medium to produce light. In these lasers, an electrical current excites the gas molecules, causing them to emit photons, which are then amplified to create a coherent beam of light. Common gases used include helium, neon, and carbon dioxide. One of the most well-known gas lasers is the helium-neon laser, which produces a red beam and is often used in barcode scanners and laser pointers. Another example is the carbon dioxide laser, which emits infrared light and is widely used in industrial applications, such as cutting and welding materials.