How Are Lasers Made?

Laser History

As with any major scientific invention, there were many stages of theory and production involved in the creation of the first laser system.

It All Started With A Theory

In 1905, Albert Einstein theorized that energy only exists in packets, a packet of energy being called a quantum. Later in 1917, he expanded on that theory and claimed it was possible to stimulate an atom and get it to release a quantum of light energy. It wasn’t until 4 decades later that a practical demonstration of Einstein’s “Quantum Theory of Light” was actually possible.

From Maser to Laser

In the late 1950’s, Charles Townes and Arthur Schawlow created a Maser (Microwave Amplification by Stimulated Emission of Radiation) that produces amplified microwaves and radio waves. At the same time Gordon Gould, a graduate student of Charles Townes, sketched a light emitting version of the maser and coined the term “laser” that we use today.

At a Manhattan news conference in 1960, Theodore Maiman became the first person to build and demonstrate a working visible light laser. Maiman had great faith in the future potential of lasers and said “a laser is a solution seeking a problem.”

He could not have been more correct. Since that day in New York, lasers have sparked the public’s imagination in countless ways. Industries across the world today rely heavily on laser technology for manufacturing, imaging, communications, medical treatment, transportation, weaponry, restoration, entertainment…the list goes on and on. The fingerprints of lasers are all around us every day.

Lasers Today

As laser applications become more varied and more in demand, the laser industry is rapidly growing every year to keep up. Laser Focus World Magazine has a careful eye on the future of the laser industry and reported on the top laser manufacturers going into 2018 that all exceeded $1 billion dollars in sales: Coherent (Santa Clara, CA), IPG Photonics (Oxford, MA), Han’s Laser (Shenzhen, China), and Trumpf (Farmington, CT).

Investing In the Future

Companies that rely upon laser manufactured parts are heavily investing in laser companies to boost their production to meet demand. Apple alone has invested hundreds of millions of dollars into a Texas based laser manufacturer, Finisar. This move was designed to make sure Finisar could keep up with Apple’s demand for laser technology today and well into the future.

What’s In A Name?

So how exactly do these in demand laser products work? L.A.S.E.R. stands for Light Amplification by Stimulated Emission of Radiation. Let’s break that down into parts to get a clearer picture.

Radiation

Rest assured that lasers do not emit the same nuclear radiation that occurs when atoms break down. Lasers emit electromagnetic radiation the same as all light and radio waves.

Stimulated Emission

Surrounding an atom’s nucleus are rings of energy like the rungs of a ladder. In its stable state, an atom’s electrons will live at the lowest energy level available. If those electrons become excited (or pumped full of energy) they can leap to a higher level. This is known as a “quantum leap”. After absorbing this energy, those electrons will leap back to their original level and a particle of light, or photon, appears. Thus scientists can stimulate atoms to get them to emit radiation and light.

Light Amplification

If a photon is fired through a large group of excited atoms, a chain reaction of leaping electrons is created, resulting in an emission of photons. Thus the light becomes amplified because one particle of light created a cascade of subsequent light bursts.

How Are Lasers Made?

There are a wide variety of lasers in production today, but all lasers require a couple of the same components.

1. A group of atoms (either solid, liquid, gas, or semiconductor) with electrons that can be stimulated to absorb energy.

2. Something to stimulate these electrons.

A Closer Look

Let’s take a look at a typical solid state red crystal laser. These lasers use a flash tube to excite the electrons within a solid ruby crystal.

1. First, a high-voltage electric flash lamp flashes on and off. 
2. Every time it flashes, photon energy is pumped into the ruby crystal.
3. Atoms within the crystal absorb this photon energy and their electrons perform a quantum leap and jump to a higher energy level.
4. Within milliseconds, the electrons leap back to their original energy level and spontaneously emit a photon of light.
5. These photons bounce up and down inside the crystal at the speed of light, exciting other electrons, which then continue to produce more and more photons.
6. The original flash of light has become exponentially amplified.
7. A mirror at 1 end of the tube keeps the photons continuously bouncing back and forth inside the crystal.
8. At the other end of the tube, a partial mirror reflects some photons back into the tube and allows others to escape to form the concentrated laser beam.

Where There Is Light…There Is Heat

As light becomes amplified with the laser, the heat radiating out from the laser is amplified as well. Laser equipment generates extremely high levels of heat, and that thermal stress can have catastrophic consequences for the laser equipment itself and the materials on which the laser is being used.

Laser Cooling Solutions From North Slope Chillers

Excessive heat can compromise a laser’s beam quality, wavelength stability, and accuracy. Reducing a laser’s operating temperature can protect materials, equipment, reduce maintenance, and increase the lifetime of the laser system. North Slope Chillers industrial laser chillers optimize laser operations and keep systems running efficiently.

Chat with a chilling expert to find the best laser chiller or chilling accessory for your needs at (866) 826-2993 or by email at [email protected].