Question

What is the difference between a gas laser and a fluorescent tube?

Answer 1

In a gas laser and a fluorescent tube, the gas atoms in the closed container is excited with a high voltage. This excited atoms come back to the normal state by releasing light of a specific wavelength that depends on the gas present. However, in a fluorescent lamp, this de excitation is in a random direction. The light ray, which is usually in the UV range gets hit on a fluorescent coating on the surface of the glass thereby changing it into visible light.

But in a LASER, a cavity is made of mirrors to selectively amplify the light in a single direction, so that a monochromatic coherent and intense beam of light is obtained. So, the difference is that of how the produced light is converted into output. The composition of gas used is also very different.