Nd: YAG crystal

Nd: YAG crystal, completely called neodymium-doped yttrium aluminum garnet crystal (Nd: Y3Al5O12), yttrium aluminum garnet crystal as its activator, the content of Nd atoms in the crystal is 0.6 ~ 1.1%, belongs to the strong laser, can thrill pulse laser or constant laser, giving off laser infrared wavelength 1.064 μm.

1. Nd: YAG

Nd: YAG crystal, completely called neodymium-doped yttrium aluminum garnet crystal (Nd: Y3Al5O12), yttrium aluminum garnet crystal as its activator, the content of Nd atoms in the crystal is 0.6 ~ 1.1%, belongs to the strong laser, can thrill pulse laser or constant laser, giving off laser infrared wavelength 1.064 μm.

Short pulse Nd YAG laser has vital applications in laser handling, photoelectric countermeasures, laser varying, laser communication, etc. Specifically, the peak power laser obtained by Q switching is the core device in numerous advanced scientific studies and also modern scientific instruments and tools.

Neodymium-doped yttrium aluminum garnet (Nd: YAG) laser crystal has the advantages of excellent optical uniformity, mechanical properties, high physical and also chemical security, great thermal conductivity, and so forth. It has ended up being the primary support product for military strong laser technology and the application direction of the medium as well as high-power lasers. It is referred to as among the “3 basic laser crystal products”, which are extensively utilized in commercial, medical, army, as well as clinical research studies.

(1) Advantages

Nd: YAG crystal is still the most widely made use of strong laser tool due to its excellent optical as well as mechanical buildings, very easy production, and also affordable. However, the research generally concentrates on the 946nm, 1064nm, as well as 1319nm wavelength lasers, as well as 1123nm laser emission is additionally a vital change.

Nd: YAG crystals have superior spectral and laser properties. It is just one of the most extensively made use of laser crystals. Compared to Nd: YVO4 crystal, the previous has high thermal conductivity, excellent mechanical properties, and simple growth, and also Nd: YAG crystal can be made use of straight; Cr YAG Q modulation to acquire peak power and also a high repeating regularity outcome.

However, because the doping focus of Nd: YAG crystal is low and also the absorption coefficient is small, it is tough to realize the miniaturization of the laser and boost its effectiveness. We have now gotten huge, very doped Nd: YAG crystals using the cozy ladder method, with the mole fraction of Nd ions doped up to 2.3.

2. Growth method

(1) Lifting method

Tira technique: Czochralsik: CZ method, a crystal growth method established by Czochralsik in 1917 fundamental concept: Under a practical temperature area, the reduced end of the seed crystal installed on the seed crystal rod is reduced into the raw product of the thaw. Under the activity of the rotary motor and lifting device, the seed crystal rod turns while gradually drawing upwards. After numerous technical phases, such as neck diminishing, shoulder growth, shoulder rotation, equal size, ending up, and carrying out, the single crystal with qualified geometric shape as well as the interior top quality is expanded.

1) Advantages of the pulling method:

(a) During the growth process, it is convenient to observe the growth of the crystal

(b) The growth of the crystal on a free surface of the thaw without contact with the crucible significantly reduces the anxiety on the crystal as well as prevents nucleation on the crucible wall

(c) It is easy to use orientated seed crystals as well as the “necking” procedure to acquire complete seed crystals and also crystals of the desired orientation. The terrific benefit of the pull-up technique is the ability to expand crystals of higher quality at a much faster price.

2) Disadvantages

(a) Possible contamination of the crystal by crucible material;

(b) The thaw’s circulation action, the transmission’s vibration, as well as the temperature change all affect the crystal’s high quality.

(2) Bridgman technique

Bridgman process is a common thaw growth technique, usually separated into vertical and also horizontal Bridgman process two.

The vertical Bridgman procedure, likewise known as the crucible descent technique, is a method of growing crystals from the thaw. Normally, when the crucible is decreased in a crystallizing heater and passes through a region with a huge temperature gradient, the thaw crystallizes in the crucible from the bottom up right into a single crystal. The formation furnace climbing along the crucible can additionally complete this process.

(3) Guided temperature level gradient technique

The guided temperature ladder technique is a solitary condensation technique of thaw caused by related seed crystals. The temperature level field of TGT is primarily changed by readjusting the form and also setting the graphite heating body, Mo insulation display, Mo crucible, the power of the heating body, and the circulation of flowing cooling water to develop a suitable temperature slope from all-time low to top.

3. Main application of Nd YAG laser

The Nd: YAG laser has a wavelength of 1064 nm and is not near the absorption height of oxygenated hemoglobin, which has inadequate Nd: YAG laser absorption. Nonetheless, its infiltration deepness can get to regarding 8 mm, to make sure that it can play a restorative function in the much deeper part of the hemangioma. According to the various energy result modes, Nd: YAG laser can be divided into continual and also pulse kind two.

Continual Nd: YAG lasers are commonly made use of but are non-selective in thermal cell damage. Continuous Nd: YAG laser is extensively made use of in the ent division, gynecology, and also surgery. And also in dermatology, as a result of the “bad aesthetic impact”, use is extra careful. Compared with continual Nd: YAG laser, pulsed Nd: YAG laser is much more consistent with selective photothermal theory. It can decrease heat damage to the bordering regular tissue and also minimize the event of scars as well as other damaging responses.