Nd: YAG crystal

1. 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%. Comes from the solid laser, which can delight pulse laser or continuous laser, producing a laser infrared wavelength of 1.064 μm.

Short pulse Nd YAG laser has essential applications in laser processing, photoelectric countermeasures, laser varying, laser interaction, etc. Particularly the peak power laser gotten by Q switching is the core device in lots of innovative scientific research studies and modern-day clinical tools and also devices.

Neodymium-doped yttrium aluminum garnet (Nd: YAG) laser crystals have excellent optical uniformity, mechanical properties, high physical and chemical stability, good thermal conductivity, and so on. It has become the main supporting material of modern technology of military solid lasers. Nd: YAG is also the application direction of medium and high-power lasers. It is called one of the "three basic laser crystal products". Commonly used in business, medical, military, and scientific research.

(1) Advantages

Nd: YAG crystal is still the most extensively used solid laser tool due to its superb optical and also mechanical buildings, very easy production, and also affordable. Nevertheless, the research mainly focuses on the 946nm, 1064nm, and 1319nm wavelength lasers, and also the 1123nm laser emission is also a vital shift.

Nd: YAG crystals have superior spooky and laser properties. It is just one of the most extensively utilized laser crystals. Compared to Nd: YVO4 crystals, the previous has high thermal conductivity, good mechanical properties, and also very easy growth, and also Nd: YAG crystal can be utilized directly. Cr: YAG Q modulation to acquire peak power and high repeating regularity outcome. However, since the doping focus of Nd: YAG crystal is reduced and the absorption coefficient is small, it is tough to recognize the miniaturization of the laser as well as boost its performance. We have actually now acquired huge, highly drugged Nd: YAG crystals using the cozy ladder method, with the mole portion of Nd ions doped up to 2.3.

2. Growth method

(1) Lifting method

Tira method: Czochralsik: CZ method, a crystal growth technique developed by Czochralsik in 1917.

Basic principle: In the actual temperature region, the seed crystal reduction end set on the seed crystal pole is lowered directly into the melt feedstock. Under the action of the rotary motor and lifting mechanism, the seed rod is gradually pulled up while rotating. After shrinking the neck, long shoulder, and shoulder rotation, such as size, shape, management, and other process stages. Finally, single crystals with qualified geometry and good internal quality are grown.

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 melt without contact with the crucible considerably reduces the anxiety on the crystal and also stops nucleation on the crucible wall.

(c) It is easy to use orientated seed crystals and also the "necking" process to obtain total seed crystals as well as crystals of the desired alignment. The great advantage of the pull-up technique is the capacity to expand crystals of higher quality at a much faster price.

2) Disadvantages

(a) Possible contamination of the crystal by crucible product.

(b) The melt's circulation activity, the transmission's vibration, and the temperature level fluctuation all influence the crystal's quality.

(2) Bridgman method

Bridgman procedure is a typical melt growth method, typically split into vertical and also horizontal Bridgman process two.

The vertical Bridgman process additionally referred to as the crucible descent method, is a technique of expanding crystals from melt. Typically, when the crucible is reduced in a taking-shape heater and goes through a region with a big temperature gradient, the melt crystallizes in the crucible from the bottom up into a single crystal. The condensation furnace climbing along the crucible can likewise complete this procedure.

(3) Guided temperature level gradient technique

The directed temperature ladder technique is a single formation technique of melt caused by related seed crystals. The temperature rating area of the TGT is mainly regulated by taking down. For example, change the graphite heating body, molybdenum insulation screen, molybdenum crucible, household heating body power, distribution of cooling water flow and other shapes and positions. Form a suitable temperature gradient from bottom to top.

3. Main application of Nd YAG laser

Nd: YAG laser wavelength is 1064 nm. Not close to the absorption height of oxygenated hemoglobin. Insufficient absorption of Nd: YAG laser. But its depth of infiltration can reach about 8mm. It can play a healing role in the deeper part of hemangioma. According to the various power outcome settings, Nd: YAG laser can be split into continual and also pulse type two.

Continual Nd: YAG lasers are frequently utilized but are non-selective in thermal tissue damage. Constant Nd: YAG laser is commonly utilized in the ent division, gynecology and surgery. And in dermatology, because of the "bad aesthetic result", usage is more careful. Compared to constant Nd: YAG laser, pulsed Nd: YAG laser is more regular with the selective photothermal concept. It can reduce heat damage to the bordering typical cells as well as lower the event of marks and other negative reactions.