What is Nd:YAG crystal

Nd: YAG

Nd: YAG, completely known as neodymium-doped yttrium aluminum garnet crystal (Nd: Y3Al5O12), yttrium aluminum garnet crystal as its activator, the material of Nd atoms in the crystal is 0.6 ~ 1.1%, belongs to the solid laser, can thrill pulse laser or continuous laser, releasing laser infrared wavelength 1.064 μm.

Short pulse Nd YAG laser has vital applications in laser processing, photoelectric countermeasures, laser varying, laser communication, etc. Specifically the peak power laser gotten by Q switching is the core device in numerous sophisticated clinical study as well as contemporary scientific instruments and also tools.

Neodymium-doped yttrium aluminum garnet (Nd: YAG) laser crystal has the advantages of excellent optical harmony, mechanical properties, high physical and also chemical stability, good thermal conductivity, and so on. It has actually come to be the major support product for armed forces strong laser innovation as well as the application instructions of medium and also high-power lasers. It is referred to as one of the “three basic laser crystal products”, which is widely utilized in commercial, clinical, military, and clinical research study.

Benefits

Nd: YAG crystal is still the most widely utilized strong laser tool as a result of its excellent optical and also mechanical residential properties, easy production, as well as low cost. Nonetheless, the research mainly concentrates on the 946nm, 1064nm, and also 1319nm wavelength lasers, as well as the 1123nm laser emission is likewise a crucial shift.
Nd: YAG crystals have superior spectral as well as laser properties. It is one of the most commonly made use of laser crystals.

Compared With Nd YVO4 crystal, the previous has high thermal conductivity, great mechanical properties, and also easy growth, as well as Nd: YAG crystal can be made use of straight; Cr YAG Q modulation to get peak power and also high repetition frequency outcome. However, because the doping focus of Nd: YAG crystal is reduced and also the absorption coefficient is little, it is hard to recognize the miniaturization of the laser and also boost its effectiveness. We have actually now gotten large, very doped Nd: YAG crystals using the warm ladder technique, with the mole fraction of Nd ions doped up to 2.3.

Growth method

Lifting method

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

Standard principle: Under a practical temperature area, the reduced end of the seed crystal set up on the seed crystal rod is decreased into the raw product of the melt. Under the activity of the rotating motor and also lifting device, the seed crystal rod revolves while slowly pulling upwards. After several technical stages, such as neck shrinking, shoulder development, shoulder turning, equivalent size, completing, as well as managing, the solitary crystal with certified geometric form as well as internal high quality is grown.

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 area of the thaw without contact with the crucible significantly reduces the stress and anxiety on the crystal and also avoids nucleation on the crucible wall surface
• It is easy to use orientated seed crystals and also the “necking” process to get full seed crystals and also crystals of the wanted positioning. The fantastic benefit of the pull-up technique is the capacity to expand crystals of higher quality at a quicker rate

Disadvantages

• Possible contamination of the crystal by crucible product;
• The thaw’s flow action, the transmission’s vibration, and the temperature variation all influence the crystal’s top quality.

Bridgman technique

Bridgman process is a common melt growth technique, generally split right into upright and straight Bridgman process 2.

The upright Bridgman procedure, also called the crucible descent method, is a technique of expanding crystals from thaw. Generally, when the crucible is reduced in a crystallizing heating system as well as travels through an area with a large temperature gradient, the melt takes shape in the crucible from all-time low up into a solitary crystal. The formation heating system rising along the crucible can also complete this process.

Guided temperature level slope method

The guided temperature ladder method is a solitary formation method of melt generated by orientated seed crystals. The temperature level field of TGT is mainly adjusted by adjusting the form as well as setting of the graphite heating body, Mo insulation display, Mo crucible, the power of the home heating body, and also the circulation of distributing cooling water to form an ideal temperature slope from all-time low to top

Main application of Nd YAG laser

The Nd: YAG laser has a wavelength of 1064 nm and is not near the absorption peak of oxygenated hemoglobin, which has bad Nd: YAG laser absorption. Nonetheless, its penetration deepness can reach regarding 8 mm, so that it can play a healing role in the deeper part of the hemangioma. According to the various energy outcome modes, Nd: YAG laser can be separated right into constant and pulse kind 2. Continuous Nd: YAG lasers are typically made use of yet are non-selective in thermal tissue damage.

Constant Nd: YAG laser is widely used in the ent department, gynecology as well as surgery. And in dermatology, as a result of the “bad cosmetic result”, use is much more cautious. Compared to continuous Nd: YAG laser, pulsed Nd: YAG laser is extra consistent with careful photothermal theory. It can reduce heat damages to the surrounding regular tissue and also reduce the incident of marks and also various other unfavorable responses.