Understanding how fluorescent light tubes work begins with a basic understanding of how light is produced. The basic unit of light is the light photon, which is released by an atom when its electrons become energized. As you may know, electrons are negatively charged particles that orbit around an atom’s positively charged nucleus. Electrons have different levels of energy, and move when energy is gained or lost by the atom. When heat passes energy to an atom, electrons quickly shift to another orbital, and almost instantaneously jump back to their original positions. As the return jump takes place, extra energy can be released in the form of a light photon, thus creating light.

We have all heard that fluorescent bulbs are more efficient than incandescent ones, but why? Fluorescent bulbs utilize a more energy efficient process of producing the light that we see. The main difference between incandescent lighting and fluorescent lighting is in the process of stimulating the atoms. Incandescent light bulbs excite atoms through the introduction of heat, resulting in an excess of unused heat energy. Fluorescent light bulbs, on the other hand, utilize a chemical reaction to excite atoms without the same excess heat energy. Both types of bulbs create ultraviolet light, which is not visible to humans. But only fluorescent bulbs utilize a substance that converts the ultraviolet light to visible light, resulting in less wasted energy.

An ordinary fluorescent lamp is a tube shaped glass shell with an electrode on each end for connecting to the electrical source. Phosphor powder lines the inside of the tube, and a small amount of mercury and an inert gas are contained within it. When current flows to and between the electrodes, electrons travel the length of the tube, creating energy that converts part of the mercury to a gas. As some of the moving atoms and electrons make contact with the mercury atoms, electrons become excited, jump to a new orbital, and emit light photons as they return to the original orbital.

However, the light created by this chemical reaction is mostly in the ultraviolet range, which again is not comprehended by the human eye. The phosphor powder lining the fluorescent lamp serves the important purpose of converting the light to visible light. When the light photons created from the chemical reaction collide with a phosphor, the energy excites the phosphor’s electrons, thus emitting visible light. Phosphors are the reason for the white light we typically see from fluorescent lights.

The popularity of fluorescent lighting is on the rise as consumers are becoming more environmentally conscious and are looking for energy saving solutions. Once widespread mainly in large office buildings and schools, the fluorescent bulb is now manufactured with a standard bulb base making it compatible with more common home light fixtures.