laser

Did you know the word laser is actually an acronym?

L.A.S.E.R. stands for “Light Amplication by the Stimulated Emission of Radiation”.

Lasers are one of mankind’s most important scientific developments and play a major role in our everyday lives. Lasers are used in almost any industry we can imagine including electronics, modern medicine, defense and more. In manufacturing, lasers are used everyday for: welding, cutting, drilling, cleaning, measuring, sensing, etching, marking, engraving and more. The laser has become one of our most powerful manufacturing tools!

To create a laser, we raise the energy level of atoms to an excited state, thereby enabling them to release light when falling back to their original energy or ground state. In this example we use two main ingredients to accomplish this; a gain medium and a pumping mechanism.

Common Gain Mediums Used in Manufacturing Process Lasers:

  • Gas
  • Nd:YAG Crystal (Neodymium Doped Yttrium Aluminum Garnet) A synthetic crystal which serves as the gain medium.
  • Nd:YVO4 Crystal (Neodymium Doped Yttrium Orthovanadate) A synthetic crystal which serves as the gain medium.
  • Fiber (Ytterbium) A doped fiber optic cable which serves as the gain medium.

Common Pumping Sources Used in Manufacturing Process Lasers:

  • Electricity
  • Arc Lamp / Bulb – A rod shaped lamp or bulb that serves as the pumping mechanism for the laser.
  • Semiconductor Diode

For example, we illustrate the basic principal behind a lamp pumped laser, also referred to as a flash lamp laser.

Flash Lamp Laser Assembly No Cooling

The pumping mechanism (lamp) excites the atoms in the gain medium (YAG crystal) to a higher state of energy.

Flash Lamp Atoms Stimulated

When the atoms fall back to their original level or ground state, they release light. The release of this light stimulates other excited atoms to release twice as much light. This is referred to as spontaneous emission. When more atoms are at a high state of excitation than low, this is referred to as population inversion.

Released Light Stimulates other Atoms

This cavity is gold plated for high reflectivity and as the amount of light or photons generated increases, it is directed in a precise path using highly and partially reflective mirrors. The partially reflective mirror contains an aperture which allows the light to escape in a uniform path, thus becoming a laser!

Release of Laser from Cavity

Lasers also share a few other attributes.

  1. Lasers are coherent. This means the peaks and troughs of the light waves are in alignment. A laser beam also travels in a uniform, single direction.
  2. Lasers are typically monochromatic. This means that only 1 wavelength is emitted. In the example above, the pumping mechanism and gain medium allowed us to produce light at 1064nm. This wavelength of light is ideal for many of the laser processes used in manufacturing.

The image below shows an example of non-coherent light. A flashlight utilizing a bulb emits light waves that are multi-directional and vary in wavelength.

Flashlight Non Coherent

The next image shows an example of coherent light. A red laser pointer emits light waves that are uni-directional and uniform in wavelength. Note that the peaks and troughs are in alignment.

Laser Pointer Coherent

To learn more about how lasers work or how we utilize laser technology in our marking, etching and engraving machines, contact us at 877-318-9562!

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