Nd-YAG Laser: Advantages and Disadvantages
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This page covers the structure, working operation, advantages, and disadvantages of the Nd-YAG laser. It mentions the benefits and drawbacks of Nd-YAG lasers.
What is an Nd-YAG Laser?
Introduction:
- Its structure and working operation are similar to the ruby laser.
- It utilizes Neodymium doped with Yttrium Aluminum Garnet (i.e., Nd:Y3Al5O12) as the active material. Nd3+ ions are used to achieve the necessary metastable states. It’s used in various scientific and medical fields.
- The Nd:YAG laser emits a lasing output wavelength of about 1.064 µm. This wavelength region is referred to as the near-infrared region. The laser also emits light at other wavelengths.
- This laser type can be used in CW (Continuous Wave) and pulse modes with a peak power of about 1000 Watts and about 2 x 108 Watts, respectively.
- Figure 1 depicts the structure of an Nd:YAG laser. As shown, it consists of an energy source (e.g., flashtube or laser diodes), an active medium (Nd:Y3Al5O12), and an optical resonator.
- The energy source supplies energy to the active medium in order to achieve population inversion. The crystal is placed between two mirrors, which are optically coated or silvered.
- This laser is a four-level laser system. This means four energy levels are employed in the laser action.
Benefits or Advantages of Nd-YAG Laser
Following are the benefits or advantages of Nd-YAG lasers:
- It is very useful for thin materials for quick processing.
- It offers high DPI (dots per inch) capabilities.
- It is also useful for applications that need high power density, such as metal marking.
- It offers higher energy output and a very high repetition rate.
- It is very easy to attain population inversion.
- It can be Q-switched for CW or pulse mode operations. This helps in minor laser ablation processes.
- Nd:YAG laser machines can cut very high reflecting materials, e.g., aluminum, copper, non-ferrous metals, which can’t be cut by other laser cutting machines.
- It is easy to operate and maintain.
- The purchasing cost is relatively lower.
Drawbacks or Disadvantages of Nd-YAG Laser
Following are the drawbacks or disadvantages of Nd-YAG lasers:
- It is not ideal to be used for materials that have moderate thickness.
- Slow production is possible for thicker materials using this laser type. Hence, it offers lower efficiency.
- It has low absorption of radiation of lighter materials very close to the visible spectrum.
- It will not allow for a larger scan gap despite high engraving resolutions. This makes the process slower.
- The electron energy level structure of Nd3+ in YAG is complex.