Nd:YVO4 crystal belongs to the tetragonal system, positive uniaxial crystal. Nd:YVO4 crystal has been commonly acknowledged as a necessary laser material considering that its growth in 1966.
Nonetheless, the scientists discovered issues in the scattering centre, absorption colour centre, and so on. It is, for that reason, difficult to expand top quality crystals of the size needed for a flash pump.
The good news is, it has exceptional absorption and gains to the wavelength of diode radiation. As well as the transmission area is enormous. The output laser has excellent polarization qualities. These suffice to cover the imperfections of its small growth size.
1. Benefits
Nd:YVO4 crystal has outstanding properties. Compared with another typically utilized Nd: YAG crystal (neodymium-doped yttrium aluminium garnet crystal),สล็อตเว็บใหญ่888 its pump broadband is more comprehensive. The absorption bandwidth efficiency is higher. The stimulated discharge cross-section is a lot more detailed and has excellent growth value. Nd:YVO4 crystals are utilized along with nonlinear optical crystals such as LBO crystals, BBO crystals, KTP crystals, and so on. It can understand frequency-doubling conversion as well as change functioning wavelength. The all-solid-state laser made of Nd:YVO4 crystal can result near-infrared light, green light, blue light, ultraviolet light and so forth.
- At about 808 nm pump transmission capacity, concerning the Nd:YAG five times
- Area at 1064 nm of the promoted discharge of radiation is an Nd:YAG three times.
- Light damage limit is low, high slope efficiency
- Uniaxial crystal axis, the output of linear polarization
2. Weak points
Compared with the typical Nd:YAG crystal, Nd:YVO4 has the advantages of a much more substantial absorption coefficient, greater emission cross section, polarization absorption and also discharge attributes, bigger absorption transmission capacity, and also insensitivity to the temperature adjustment of the diode. Consequently, it is commonly made use of in LD-pumped solid-state lasers.
Nevertheless, it has a large exhaust cross-section as well as a brief upper power life time. The power storage space capacity of Nd:YVO4 is a lot less than that of Nd:YAG. Not for high energy, peak power of the Q – switched pulse result. Their advantages are limited to constant wave outcome, high ordinary control, and also high conversion performance. Furthermore, the thermal conductivity of Nd:YVO4 is really small, only half that of Nd:YAG. As a result, it is not for attaining high-power constant wave result.
3. Applications
Neodymium-doped yttrium vanadate (Nd:YVO4) crystal is a type of laser crystal with outstanding efficiency, which is suitable for manufacturing a laser diode pump, specifically a low-power laser. Compared with Nd:YAG, Nd:YVO4 has a greater absorption coefficient and also larger stimulated exhaust cross-section.
Laser diode-pumped Nd:YVO4 crystals are combined with LBO, BBO, KTP as well as various other crystals with high nonlinear coefficients. It can achieve better frequency-doubling conversion efficiency. It can output near-infrared, green, as well as blue ultraviolet and solid-state lasers.
Nd:YVO4 crystals can be extensively utilized in optical interaction, industrial laser handling, laser varying, semiconductor discovery, data storage space, display, laser printing, clinical inspection, equipment, clinical study and various other fields.
In addition, Nd:YVO4 diode-pumped solid-state lasers are swiftly changing conventional water-cooled ion lasers and also lamp-pumped lasers in the marketplace, specifically in regards to miniaturization as well as single longitudinal mode outcome.
In the 21st century, several downstream markets of Nd:YVO4 crystal is booming, and also the application series of Nd:YVO4 crystal is regularly increasing with apparent efficiency benefits.
4. Growth method
In the 1960s, Nd:YVO4 crystal was developed. It was drawn out from sodium metavanadate melt by the air conditioning technique. The size of the Nd:YVO4 crystal grown by this method was tiny. Ever since, the growth process of Nd:YVO4 crystal has actually been put forward, such as the Zhilar method, fire melting method, floating zone growth method, Bryman method and also pull method. At present, the development approaches of Nd:YVO4 crystal are numerous. The illustration approach is the mainstream Nd:YVO4 crystal development process, which can grow huge, high-quality crystals.
Pulling method
Nd3+:YVO4, crystal melting point is really high (regarding 1820 ℃), should utilize gold-dependent crucible development, gold-dependent crucible will be oxidized at high temperature, need to use a neutral gas (hydrogen) to safeguard the crucible.
By doing this, growing in an anoxic atmosphere, the melted component will decompose into low-priced vanadium oxide (part of YVO4 will certainly break down right into YVO3), and also oxygen shortage will certainly happen in the crystal, resulting in the generation of the colour centre.
Growing in an oxygen-rich atmosphere will certainly lead to serious oxidation of the crucible. The lowered episcopes form additions inside the crystal. This will result in solid melt volatilization, causing element deviation.
By using various expanding ambiences in different phases, the oxygen shortage in the crystal can be supplemented, the volatilization of raw materials can be hindered, the single-phase growth of the crystal can be ensured, and also the crystal can not be smudged or spread because of oxygen deficiency due to hypoxia.
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