Nd: YVO4 crystal belongs to the tetragonal system, positive uniaxial crystal. Nd: YVO4 crystal has actually been commonly identified as a vital laser product given its development in 1966.
However, the scientists found problems in the scattering center, absorption color centre, etc. It is, as a result, impossible to grow high-grade crystals of the dimension needed for a flash pump.
Fortunately, it has excellent absorption as well as gains to the wavelength of diode radiation. And also the transmission area is enormous. The result laser has excellent polarization qualities. These suffice to cover the imperfections of its small growth size.
1. Benefits
Nd: YVO4 crystal has exceptional properties. Compared with another typically utilized Nd: YAG crystal (neodymium-doped yttrium aluminum garnet crystal), its pump broadband is extra substantial. The absorption transmission capacity effectiveness is higher. The boosted discharge cross-section is more thorough as well as has excellent growth value. Nd: YVO4 crystals are made use of together with nonlinear optical crystals such as LBO crystals, BBO crystals, KTP crystals, and so on. It can realize frequency-doubling conversion as well as change working wavelength. The all-solid-state laser made of Nd: YVO4 crystal can output near-infrared light, green light, blue light, ultraviolet light, and so forth.
- At concerning 808 nm pump data transfer, concerning the Nd: YAG five times
- Section at 1064 nm of the stimulated emission of radiation is an Nd: YAG three times
- Light damage limit is low, high slope performance
- Uniaxial crystal axis, the outcome of linear polarization
2. Weaknesses
Compared with the standard Nd: YAG crystal, Nd: YVO4 has the advantages of a more considerable absorption coefficient, greater emission cross section, polarization absorption and exhaust characteristics, larger absorption bandwidth, as well as ignorance to the temperature level modification of the diode. As a result, it is commonly made use of in LD-pumped solid-state lasers.
Nonetheless, it has a large exhaust cross-section and a short top energy life time. The energy storage capability of Nd: YVO4 is much less than that of Nd: YAG. Not conducive to high power, peak power of the Q – switched pulse outcome. Their advantages are restricted to continuous wave output, high typical control, and high conversion efficiency. Additionally, the thermal conductivity of Nd: YVO4 is extremely tiny, only fifty percent that of Nd: YAG. Consequently, it is not conducive to achieving high-power continuous wave result.
3. Apply.
Neodymium-doped yttrium vanadate (Nd: YVO4) crystal is a kind of laser crystal with exceptional efficiency, which appropriates for making a laser diode pump, particularly a low-power laser. Compared with Nd: YAG, Nd: YVO4 has a greater absorption coefficient and also larger promoted emission cross-section.
Laser diode-pumped Nd: YVO4 crystals are integrated with LBO, BBO, KTP and various other crystals with high nonlinear coefficients. It can attain much better frequency-doubling conversion performance. It can output near-infrared, green, and blue ultraviolet as well as solid-state lasers.
Nd: YVO4 crystals can be extensively utilized in optical communication, commercial laser processing, laser varying, semiconductor discovery, data storage, screen, laser printing, medical assessment, equipment, scientific research and other fields.
In addition, Nd: YVO4 diode-pumped solid-state lasers are rapidly changing standard water-cooled ion lasers and lamp-pumped lasers in the marketplace, particularly in terms of miniaturization and single longitudinal mode result.
In the 21st century, lots of downstream markets of Nd: YVO4 crystal is growing, as well as the application range of Nd: YVO4 crystal is constantly increasing with noticeable efficiency benefits.
4. Growth method.
In the 1960s, Nd: YVO4 crystal was created. It was extracted from salt metavanadate thaw by the cooling technique. The size of the Nd: YVO4 crystal expanded by this technique was small. Ever since, the growth procedure of Nd: YVO4 crystal has 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 techniques of Nd: YVO4 crystal are numerous. The drawing method is the mainstream Nd: YVO4 crystal growth process, which can expand large, top quality crystals.
4.1 Pulling method.
Nd3+: YVO, crystal melting point is very high (about 1820 ℃), must utilize gold-dependent crucible growth, gold-dependent crucible will be oxidized at high temperature, should use a neutral gas (hydrogen) to safeguard the crucible.
In this way, growing in an anoxic environment, the melted component will certainly decompose into low-priced vanadium oxide (part of YVO4 will disintegrate right into YVO3), and oxygen deficiency will happen in the crystal, resulting in the generation of the colour centre.
Growing in an oxygen-rich ambience will cause severe oxidation of the crucible. The minimized episcopes create incorporations inside the crystal. This will certainly cause strong thaw volatilization, resulting in component inconsistency.
By utilizing different expanding ambiences in different phases, the oxygen deficiency in the crystal can be supplemented, the volatilization of basic materials can be hindered, the single-phase growth of the crystal can be guaranteed, and the crystal can not be smudged or scattered due to oxygen shortage because of hypoxia.
