Nd:YAG crystal, also known as neodymium-doped yttrium aluminum garnet crystal (Nd:Y3Al5O12), yttrium aluminum garnet crystal as its activator, the crystal contains 0.6-1.1% Nd atoms, belongs to the strong laser, can thrill pulse laser or continuous laser, producing laser infrared wavelength 1.064 m.
Short-pulse Nd:YAG lasers have important applications in laser handling, photoelectric countermeasures, laser ranging, laser communication, and so on. The peak power laser obtained through Q switching, in particular, is the central device in numerous innovative scientific studies as well as modern clinical instruments and tools.
Neodymium-doped yttrium aluminum garnet (Nd:YAG) laser crystal has the advantages of excellent optical harmony, mechanical properties, high physical and chemical security, great thermal conductivity, and so on. It has evolved into the primary support material for military strong laser innovation, as well as the application direction of medium and high-power lasers. It is one of the “three basic laser crystal materials” that are widely used in industrial, clinical, and military settings, as well as clinical research studies.
Benefits of Nd:YAG crystal
Nd:YAG crystal is still the most commonly utilized solid laser tool because of its excellent optical and mechanical properties, easy manufacturing, and low cost. However, the study generally focuses on the 946nm, 1064nm, and 1319nm wavelength lasers, as well as the 1123nm laser discharge, which is likewise an important transition.
Nd:YAG crystals have superior spectral and laser properties. It is one of the most extensively used laser crystals. In comparison to Nd:YVO4 crystal, the former has high thermal conductivity, good mechanical properties, and simple development, and it can also be used directly; Cr:YAG Q modulation to obtain peak power and a high resonance frequency result. However, due to the fact that the doping concentration of Nd:YAG crystal is reduced and the absorption coefficient is tiny, it is tough to realize the miniaturization of the laser and also improve its performance. We have now obtained large, highly doped Nd:YAG crystals utilizing the cozy ladder method, with the molecular portion of Nd ions doped up to 2.3.
Growth method of Nd:YAG crystal
Lifting method
Tira method: Czochralsik: CZ technique, a crystal growth method established by Czochralsik in 1917
Basic concept: Under a reasonable temperature range, the lower end of the seed crystal mounted on the seed crystal pole is lowered right into the raw product of the melt. Under the activity of the rotary electric motor and also the lifting mechanism, the seed crystal rod revolves while gradually pulling upwards. The single crystal with a qualified geometric shape as well as an inner quality is grown after several technological stages such as neck shrinking, shoulder growth, shoulder rotation, achieving equivalent size, ending up, and pulling off.
1) Advantages of the drawing method:
- During the growth process, it is convenient to observe the growth of the crystal
- The growth of the crystal on a free surface of the melt without contact with the crucible significantly decreases the anxiety on the crystal and also avoids nucleation on the crucible wall
- It is easy to use orientated seed crystals and also the “necking” process to get full seed crystals as well as crystals of the desired positioning. The terrific benefit of the pull-up approach is the capacity to expand crystals of better at a much faster rate
2) Disadvantages
- Possible contamination of the crystal by crucible product;
- The thaw’s circulation activity, the transmission’s resonance, and also the temperature variation all impact the crystal’s quality.
Bridgman technique
Bridgman procedure is a common melt growth method, typically separated into vertical and straight Bridgman procedure two.
The upright Bridgman procedure, additionally known as the crucible descent method, is a technique of growing crystals from thaw. Typically, when the crucible is reduced in a taking shape heater as well as travels through an area with a big temperature level slope, the thaw crystallizes in the crucible from the bottom up into a solitary crystal. The condensation heater increasing along the crucible can also finish this procedure.
Guided temperature level slope method
The guided temperature ladder technique is a thawing caused by oriented seed crystals single crystallization approach. The temperature level area of TGT is mainly adjusted by adjusting the shape as well as position of the graphite home heating body, the Mo insulation display, the Mo crucible, the power of the home heating body, and also the circulation of distributing cooling water to develop an ideal temperature level gradient from the bottom to the top.
Main application of Nd YAG laser
The Nd:YAG laser has a wavelength of 1064 nm and is also not near the optimal absorption of oxygenated hemoglobin, which has poor Nd:YAG laser absorption. However, its penetration depth can reach about 8 mm to make sure that it can play a healing function in the much deeper part of the hemangioma. The Nd:YAG laser can be classified as continuous type 2 or pulse type 2, depending on the energy output settings. Constant Nd:YAG lasers are generally used but are non-selective in thermal cells.
Constant Nd:YAG lasers are commonly utilized in the ENT department, gynecology, and surgical procedures. As well as in dermatology, because of the “bad aesthetic result,” use is much more mindful. Compared to continuous Nd:YAG lasers, pulsed Nd:YAG lasers are more constant and have a more discerning photothermal concept. It can minimize heat damage to the bordering typical tissue and lower the occurrence of marks and other negative reactions.
Read more: Properties and applications of laser glass
