Nd: YVO4 crystal belongs to the tetragonal system, positive uniaxial crystal. Nd: YVO4 crystal has been commonly acknowledged as an essential laser product considering its development in 1966.
Nevertheless, the scientists found flaws in the scattering centre, absorption colour centre, and so on. It is, consequently, difficult to expand high-grade crystals of the dimension needed for a flash pump.
The good news is, it has outstanding absorption as well as gains to the wavelength of diode radiation. And the transmission section is massive. The outcome laser has excellent polarization features. These are enough to cover the imperfections of its little development dimension.
Benefits
Nd: YVO4 crystal has exceptional properties. Compared to another frequently utilized Nd: YAG crystal (neodymium-doped yttrium aluminium garnet crystal), its pump broadband is a lot more extensive. The absorption data transfer efficiency is higher. The promoted exhaust cross-section is extra extensive as well as has superb advancement worth. Nd: YVO4 crystals are utilized in conjunction with nonlinear optical crystals such as LBO crystals, BBO crystals, KTP crystals, etc. It can recognize frequency-doubling conversion and also change working wavelength. The all-solid-state laser constructed from Nd: YVO4 crystal can outcome near-infrared light, green light, blue light, ultraviolet light and so on.
- Regarding 808 nm pump transmission capacity, concerning the Nd: YAG five times
- The section at 1064 nm of the promoted discharge of radiation is an Nd: YAG 3 times.
- Light damage limit is reduced, high incline performance
- Uniaxial crystal axis, the output of linear polarization
Weaknesses
Compared to the typical Nd: YAG crystal, Nd: YVO4 has the advantages of a more substantial absorption coefficient, higher emission sample, polarization absorption as well as emission attributes, larger absorption transmission capacity, and also insensitivity to the temperature level modification of the diode. For that reason, it is commonly utilized in LD-pumped solid-state lasers.
Nonetheless, it has a big emission cross-section as well as a brief upper energy lifetime. The energy storage capacity of Nd: YVO4 is much less than that of Nd: YAG. Not conducive to high energy, peak power of the Q – changed pulse result. Their benefits are limited to constant wave results, high average control, as well as high conversion effectiveness. Additionally, the thermal conductivity of Nd: YVO4 is very small, only half that of Nd: YAG. As a result, it is not for accomplishing high-power continual wave results.
Apply
Neodymium-doped yttrium vanadate (Nd: YVO4) crystal is a kind of laser crystal with exceptional performance, which is appropriate for making a laser diode pump, particularly a low-power laser. Compared with Nd: YAG, Nd: YVO4 has a greater absorption coefficient and a bigger boosted emission cross-section.
Laser diode-pumped Nd: YVO4 crystals are integrated with LBO, BBO, KTP and also other crystals with high nonlinear coefficients. It can attain much better frequency-doubling conversion performance. It can outcome near-infrared, green, as well as blue ultraviolet as well as solid-state lasers.
Nd: YVO4 crystals can be extensively made use of in optical communication, industrial laser processing, laser ranging, semiconductor detection, data storage space, display, laser printing, clinical assessment, machinery, scientific research study as well as various other fields.
Additionally, Nd: YVO4 diode-pumped solid-state lasers are swiftly replacing standard water-cooled ion lasers as well as lamp-pumped lasers out there, specifically in regards to miniaturization as well as single longitudinal mode outcome.
In the 21st century, lots of downstream markets of Nd: YVO4 crystal is expanding, as well as the application variety of Nd: YVO4 crystal is constantly expanding with apparent performance advantages.
Growth method
In the 1960s, Nd: YVO4 crystal was created. It was removed from salt metavanadate melt by the cooling method. The dimension of the Nd: YVO4 crystal expanded by this method was tiny. Ever since, the development procedure of Nd: YVO4 crystal has been advanced, such as the Zhilar method, fire melting method, floating area growth method, Bryman method and pull method. Presently, the development techniques of Nd: YVO4 crystal are numerous. The illustration technique is the mainstream Nd: YVO4 crystal development procedure, which can grow big, top-notch crystals.
4.1 Pulling method.
Nd3+: YVO4, crystal melting point is really high (regarding 1820 ℃), need to make use of gold-dependent crucible growth, gold-dependent crucible will certainly be oxidized at high temperature, should utilize a neutral gas (hydrogen) to shield the crucible.
This way, growing in an anoxic atmosphere, the melted component will certainly decompose right into inexpensive vanadium oxide (part of YVO4 will certainly decompose into YVO3), as well as oxygen deficiency will certainly happen in the crystal, resulting in the generation of the colour centre.
Growing in an oxygen-rich environment will result in severe oxidation of the crucible. The lowered episcopes create additions inside the crystal. This will bring about strong melt volatilization, causing element discrepancy.
By using different expanding ambiences in numerous phases, the oxygen deficiency in the crystal can be supplemented, the volatilization of basic materials can be inhibited, the single-phase growth of the crystal can be assured, as well as the crystal can not be blackened or scattered because of oxygen shortage as a result of hypoxia.
