When we think of lasers, we may conjure up something in science fiction.  Lasers, however, are a part of our everyday world, making slicing and transforming   materials much simpler in industry.  In laser material processing, a laser will make contact with an object and alterations to that object will occur, such as through the soaking up of photons, which are particles of light emitted from the laser.  These particles will be altered into heat energy.  

How Lasers Actually Work

Lasers are the instruments that control how highly stimulated atoms release photons to create a stream of light.  There are only three things that can occur when a laser makes contact with an object.  The laser beam will either be reflected, sent, or it will be drawn into the object.  Sometimes two or three of these occurrences, such as transmission and absorption, may happen simultaneously.  The beam will be one wavelength and a certain color as well as tight and concentrated, unlike beams of light encountered in everyday life. If most of the beam is soaked up into an object, which is most often the case in laser material processing, the main traits that have to be taken into account are the average strength the laser light has, its intensity on the subject it hits, and its wavelength.  Intensity on a basic level is the brightness of the laser beam. The wavelength is the series of waves the photons produce.  Think of a rippling water wave, the photons are fluctuating in the same type of wave.  The average power of a laser beam is measured in watts (W).  Lasers all contain an active medium that takes in energy.  The medium can be composed of either a solid crystal-like material, fluid, gas (such as in a CO2 laser), or a diode, and holds the atoms absorbing the energy.  A laser additionally has to have a way to make the atoms become excited.  This could be a light source, for example.  

The optical resonator is a pair of mirrors in the laser system.  One of the functions of a laser is to pump up the atoms to get them excited.  This is done by pumping up what is called a lasing medium inside the laser. At each end of the lasing medium is a mirror.  light particles reflect off of both of them and energize other electrons to emit even more photons.  The mirror at one extreme allows some light escape, which forms what is known as the laser beam. Getting the atoms excited involves getting their matching electrons at a advanced level of energy.  The excited electrons that initially soaked in energy to get excited can now give off energy as light energy, or a flow of photons.     

Laser Classifications

Lasers are rated according to the traits of average power, wavelength, and intensity.  This implies they are either solid-state, liquid, gaseous, or semi conductor lasers.  Solid-state are lasers with material that is optically see-through and the active medium is solid.  Liquid, or dye lasers have a environment that is liquid and they can operate with pulsing or continuous wavelengths.  Gas lasers have an environment of gas.  Examples of gas lasers are CO2 lasers and neon signs seen in shop displays.  And the fourth group is semi conductor or diode lasers that are the most commonly found laser today.

Lasers and Cutting Applications

Using CO2 lasers as an illustration, carbon dioxide gas atoms become energized at a low pressure between two mirrors.  One of the two reflective mirrors lets some of the beam leak through.  They make a huge amount of heat.  The light emission is found in the infrared spectrum at the end. Having a beam of high quality is paramount, especially in cutting.  Lasers cut by using the light beam the laser makes.  The beam starts by melting what is in front of it or sometimes vaporizing the material.  Cutting occurs when the beam has gone completely through the object. There are different types of lasers designed to cut different types of objects.  CO2 lasers have high capacities for absorption, and are commonly used in the cutting of plastics, wood, stainless steel, carbon steel, aluminum, and other metals such as titanium.  CO2 lasers have other materials in them besides carbon dioxide; they have a mixture of gases including helium (He) and nitrogen (N2).  Nitrogen will slice up to ½ inch thick stainless steel in addition to aluminum.  Oxygen is able to slice carbon steel. Laser cutting advantages include no wear and tear on machinery, are faster than using other methods of cutting, and can cut through thicker materials.  

Lasers have uses ranging from communications to uses in the field of medicine.  They have revolutionized methods of conducting surgery as well as methods in industry.  It is interesting to see what will happen in the future with laser cutting abilities.

Marc Anderes is the VP of Operations of Maloya Laser that is dedicated to <A href=”http://www.MaloyaLaser.com”>Laser Cutting</a> and Metal Manufacturing with advanced <A href=”http://www.maloyalaser.com/capabilities_equipment.php”>laser technologies</a>, servicing machinery, aerospace, medical, scientific and transportation requirements.

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