The low-down on lasers

In our modern world, lasers are used in many different applications. Some lasers are very simple, such as laser pointers used in presentations or to measure distances. Others are extremely powerful and can cut or weld metals or mark all sorts of polymers. Then again, some lasers are so precise that they can be used for eye surgery. Yes, lasers are fascinating. So fascinating in fact that many of us love the idea that we can create laser swords. But this is over the top!

The purpose of this text is to give you the essentials about lasers and introduce you to the necessary vocabulary, so you can talk to laser experts. In fact, we even have to start with the term LASER, as an acronym for “light amplification by stimulated emission of radiation,” which means that this type of light consists of monochromatic (only one wavelength), directed (polarized), and aligned (amplitude) radiation. 

When you have finished reading this text, we hope you will feel a little more confident in finding the right equipment for your application and using light as a powerful tool to improve your processes where possible. 

Basically, laser light is produced when electrons become excited and move up to a higher- energy orbit. When the electrons return to the lower-energy orbit, they emit photons that are aligned in amplitude, wavelength, and polarization. For this process, an active medium is required to provide the protons. It can be either glass, a gas, or a crystal. The alignment results in a powerful laser beam. And the active medium defines the wavelength and creates UV lasers or IR lasers (see table). 

 A laser can be considered a very powerful flashlight. We've already heard that all you need to produce a laser beam is a power supply, a lamp, and the active medium that emits the energy. This emission can be either continuous or pulsed. When the energy is emitted continuously, you have a continuous flow of power that is equal to the maximum energy of your laser, for example 10 W. But if you trap the energy inside the active medium with mirrors, you amplify the energy to a multiple of this power because the radiation is equal and adds up.

Let us imagine that we are collecting the energy: How many waves can overlap? If the light moves at 299, 792, and 458 m/s and we have a laser with a wavelength of 1064 nm (= 1064 * 10-6 nm), this gives you the number of waves trapped in one second: c/ʎ is then 3, * 1012 waves. This is how you can produce 3 GW (gigawatt) from 10 W.  You may now understand why a shorter pulse length is even more powerful than a longer one. The pulse length is another way of differentiating the laser types.