What is an Nd:YAG laser? Mr Beam explains
A Nd:YAG laser is a solid-state laser that is in high demand in industry and some other sectors. This type of laser is characterized by the fact that it emits infrared radiation, typically in the wavelength 1064 nm (near infrared) through optical stimulation. Rarely, there are also variants that radiate in the wavelength range 940 nm - 1330 nm due to an adapted crystal structure. Laser radiation in the near-infrared range has many advantages in certain applications. This is necessary in metalworking and materials testing, among other things. If you want to pronounce the term, just say "neodymium jag laser".
To designate the Nd:YAG laser
The term "Nd:YAG" which appears complicated is an abbreviation. "Nd" stands for "neodymium-doped". Neodymium is a chemical element and is one of the rare earths. Nd is the official element symbol. Neodymium can also be found under this abbreviation in the periodic table, where it is listed under the lanthanides and the atomic number 60. It is a silvery-white and yellowish material that is used in MRI scanners, hard drives and paints, among other things. In addition, neodymium is a component of the Nd:YAG laser described here. Neodymium is also used in magnets, which are then particularly strong. Made from an alloy of neodymium, iron and boron, they are currently the strongest commercially available magnets.
Chemical substances are also hidden behind the term "YAG". "YAG" is short for yttrium, aluminium and garnet. The well-known aluminium is a very light but robust metal. Like neodymium, yttrium is also a chemical element. It is both a transition and a rare earth metal. By "garnet" is meant the garnet group, which includes various minerals of the silicate and germinate types.
Yttrium, aluminium and garnet are combined in the Nd:YAG laser to form a laser crystal (Y3Al5O12). This is the laser-active medium within the solid-state laser. This YAG laser crystal is neodymium-doped during manufacture. This means that neodymium ions are integrated into the laser crystal.
Evolution and similar laser types
The first laser of this type was manufactured in the 1960s. The US scientists LeGrand van Uitert and Joseph E. Geusic, who worked for Bell Laboratories (AT&T) and later also filed a patent, were responsible. A previous model did not use YAG, but instead included glass. What is meant is the Nd:glass laser. This variant is still in use.
With the Nd:YAG laser, the Nd:KGW laser and Co., there are other lasers of this type, but they have different properties. In addition, not only the YAG but also the Nd can be replaced, resulting in new properties. For example, the element ytterbium , with which a Nd:YAG laser can be produced, is conceivable as a Nd substitute.
The Nd:YAG laser is used in these areas of application
A laser of this type is extremely useful. So it is not surprising that you can discover it in many everyday areas of application. It is also possible that you could be dependent on the performance of a Nd:YAG laser for your physical health. The solid-state laser is characterized by its amazing precision in all work, so that the desired result is very likely to occur if used correctly.
One of the most important applications is the processing of materials. With a laser of this type, you can cut sheet metal, whereby thicker sheet metal can also be processed without any problems. He also helps with drilling in the micro range and with welding. In addition, materials can be tested with a Nd:YAG laser. This succeeds without destroying the tested material, because the laser can also stimulate materials to vibrate in the ultrasonic range. This non-destructive process is very valuable for many laser applications.
Another major area of application is medicine. The emitted radiation can smash kidney stones, among other things, and be useful in the treatment of haemangiomas. The Nd:YAG laser is also indispensable in ophthalmology, surgery and dentistry. So there are numerous medical indications that allow the use of this laser.
- killing cancer cells
- testing of materials
- Cutting, drilling, welding sheet metal
- Treatment of varicose veins and haemangiomas
- Removal of pigment spots, wrinkles and body hair
- Removal of unloved old tattoos
- as a decorative laser in the context of laser shows as a strong laser pointer (here, laser light with a green colour is generated from the actually invisible laser radiation by frequency doubling via crystal)
- and many more
How the Nd:YAG laser works
The functionality is based on a chemical-physical principle. During so-called pumping, the neodymium on the laser crystal is excited. This means that the neodymium is supplied with light in a targeted manner. This light contains a certain amount of energy that converts the electrons in the neodymium atoms to another energy level. Due to this physical excitation, the neodymium itself finally emits radiation in the form of a photon. The emitted photons are reflected and forth in the so-called laser cavity. They use the eponymous LASER effect (Light Amplification with Stimulated Emission of Radiation): every photon that passes an electron at a high energy level stimulates the emission of another photon. This equals the first in frequency, phase, polarization and direction. This increases the radiation enormously.
To better illustrate the usefulness of this emitted radiation, here's an example from medical practice: If a doctor wants to kill diseased cells in his patient, he can aim the Nd:YAG laser at that spot. The laser irradiates the desired area, generating a great deal of heat in the cells and thus leading to the death of the diseased tissue. It is also possible to work in somewhat deeper tissue layers.
The power of the Nd:YAG laser
This type of laser is known for its high power. However, it is not the strongest laser. The Nd:YVO4 laser and the Nd:YALO3 laser are considered to be even more powerful. Nevertheless, the Nd:YAG laser brings just the right amount of energy for some highly relevant areas of application. It has proven that its power is not too powerful, but limited. Whether in medicine or materials management: In many applications, surrounding tissue and materials should be protected. This is possible with a laser of this type.
Advantages and disadvantages of the YAG laser
A YAG laser convinces with its numerous advantages, including:
- good performance
- high precision
- protects tissue and materials
- works with different wavelengths
- low side effects during medical interventions
However, one should be aware that this laser also has disadvantages:
- sometimes complex to use
- requires the greatest caution and a great deal of know-how, especially in medicine
- rather low penetration depth (this is particularly relevant in medicine)
- safety goggles should be worn when working with the laser
Cost of a Nd:YAG laser
The new price for an Nd:YAG laser, which is intended for cosmetic purposes, starts in the middle four-digit range - but you have to pay significantly more for quality products with a claim to operational reliability. For devices that are used in industry, significantly higher costs are also common. Usually, the costs scale with the performance of the system. However, if you want to buy a Nd:YAG laser, you should not only think about the acquisition costs: There are also costs for installation, safety precautions and instructions and last but not least for maintenance. For maintenance and repairs, for example, maintenance contracts are common. Since this work can only be carried out by trained professionals, high costs are to be expected.
Conclusion: It doesn't work without a Nd:YAG laser
Despite its unwieldy name, the Nd:YAG laser is absolutely indispensable. Without devices of this type, many industries would not be able to work nearly as productively as they do today. Another very important area of application is medicine. Whether it's cancer treatment or a cosmetic problem, this amazing laser can make a big difference and help a lot of people.
Although these devices are expensive and have some disadvantages, such as the need to wear safety glasses while working, they are considered to be extremely useful. It is therefore very likely that the laser will accompany mankind for a long time to come.
Cover picture: © iStock.com/ surasakpetchang
Image 2: © iStock.com/mardoz
Image 3: © iStock.com/wangmando
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