How Do Neon Lights Work ?
From restaurants and bars to office brand logos or simply for your aesthetic bedroom decor, custom neon signs are the raging look nowadays. They are vibrant and eye-catching and can completely change the atmosphere of its surroundings and make it peppier. Neon signs in offices can give a modern yet retro look.
Neon lights in your household decor bring a unique zest to your aesthetic and make the house look more lively. Of course, you can create a faux custom neon sign and can take the help of lots of DIY tutorials. But have you ever wondered how natural neon lights work? How are they so bright and vibrant? How do they produce such eye-catching colors? Let us dive into this.
What are neon lights?
First of all, what is neon lighting? Neon lighting involves electrified glass tubes or bulbs with a brilliant glow. These glass tubes or bulbs contain rarefied neon gases. Now, what are rarefied gases? It means that the gas is condensed to a pressure less than the atmospheric pressure. This helps in containing the gases in the small tubes or bulbs. Now, neon lights are a kind of cold cathode gas-discharge light.
The neon tube with the gas inside is sealed properly using metal cathodes at each end. The electricity provided to these cathode strips ionizes the atoms in the contained gas inside the tube. The electrons of these ions then move towards the terminals of the lamp and thus complete the electric circuit. When these ionized neon atoms have enough charge and gain sufficient energy to get excited, they produce light.
This depends on the movement of the particles along different energy states. When an atom jumps from one energy level to another, it emits energy. So, when the ionized atoms of the neon gas present inside the bulb jump from a higher energy level to a lower, it releases a photon (i.e., light), and the bulb starts to glow. The color the photon produces will depend on the gas filled inside it.
Let's break this down and understand it a little bit more in detail.
Why is neon used in them? How does the mechanism work?
First of all, why are they called neon lights? This is because the noble gas 'neon' naturally gives off an orange light when it undergoes this process. At the same time, the other colors have to be produced using various other gases and chemicals. So that's how it got its name. Now let's understand the process a little better.
You may ask, why is neon, specifically, used for this purpose? Why not various other gases like oxygen or nitrogen? Neon is used because it is a noble gas. It is a defining property of the noble gases that each atom of a noble gas has a completely filled electron shell. So, they are non-reactive in nature. To remove an electron from this filled shell, a large amount of energy needs to be supplied to these atoms to excite them. Custom neon signs or neon lights use either alternating current (AC) or direct current (DC), but when used with a direct current, the light only glows around one electrode. That is why neon lights usually use alternating current for emitting light.
Now the tube within which the gas is present has electrodes on both ends of the tube. When electricity is applied to these cathode terminals (an electric voltage of almost 15,000 volts needs to be used), the energy required to detach an outer electron from the electron shell of the neon atoms is given. If the voltage supplied proves insufficient, the kinetic energy necessary for the electrons to escape will not be enough for the process to occur.
When sufficient kinetic energy is provided, the positively charged atoms will move towards the negative terminal. The free electrons (that is, the negatively charged ones) will attract towards the positive end. The negatively or positively charged particles form the fourth state of matter called plasma and complete the electric circuit.
How do they produce light?
So we have understood the entire mechanism of how a neon tube is charged and produces energy. Where does the light come from? The atoms in the tube move around when they get excited due to gaining energy, hitting each other, and constantly exchange energy.
They are, therefore, at a higher energy state. But that is not the natural configuration of the atoms. They will try to lose their energy to go back to their ground state. To do that, they need to release the energy in them. When they do so, the energy is released in the form of a photon (light), and that is how light is produced by these neon tubes. The color, as we have already discussed, depends on the nature of the gas.
But, it also depends on the energy level from which the atom has released the energy. There are numerous energy levels at which an atom can exist. Depending on the energy level from which a particular atom releases its energy to go back to its original state and the distance between these energy levels, the color of the emitted photon particles will change.
To put it simply, each excited electron emits a particular wavelength of the photon. So, the color varies accordingly. Consequently, each noble gas will have a characteristic color it emits. For example, neon has a reddish-orange light, whereas helium has a pink glow.
A custom neon sign can be made in a variety of shapes and colors. They are mainly used as sign boards or wall art at bars or restaurants. Even offices are increasingly using designer custom neon signs to beautify their office spaces and make the office environment high-spirited and exuberant.
Neon lights are somewhat similar to fluorescent lights as well. Still, fluorescent lighting developed almost 25 years after the neon lighting system and is usually used for getting a bright white light. Neon lights are also used in neon glow lamps and plasma displays. Neon lights in recent times have also become an art style popular over Europe and the USA.