Nd: YVO4 crystal belongs to the tetragonal system, positive uniaxial crystal. Nd: YVO4 crystal has been widely recognized as an important laser material given its development in 1966.
Nevertheless, the researchers found defects in the scattering center, absorption color center, and so on. It is, as a result, difficult to grow top-notch crystals of the size needed for a flash pump.
Luckily, it has exceptional absorption and gains to the wavelength of diode radiation. And the transmission section is massive. The result laser has good polarization characteristics. These suffice to cover the imperfections of its little development dimension.
Advantages
Nd: YVO4 crystal has excellent properties. Compared with another generally used Nd: YAG crystal (neodymium-doped yttrium aluminum garnet crystal), its pump broadband is more comprehensive. The absorption bandwidth effectiveness is higher. The promoted exhaust cross-section is much more thorough and also has excellent development value. Nd: YVO4 crystals are made use of together with nonlinear optical crystals such as LBO crystals, BBO crystals, KTP crystals, etc. It can realize frequency-doubling conversion as well as readjust functioning wavelength. The all-solid-state laser constructed from Nd: YVO4 crystal can result in near-infrared light, green light, blue light, ultraviolet light, and so forth.
- Regarding 808 nm pump transmission capacity, concerning the Nd: YAG five times
- The area at 1064 nm of the promoted emission of radiation is an Nd: YAG three times.
- The light damage threshold is low, with high slope effectiveness
- Uniaxial crystal axis, the output of linear polarization
Weak points
Compared with the conventional Nd: YAG crystal, Nd: YVO4 has the advantages of a more significant absorption coefficient, greater emission random sample, polarization absorption and also exhaust characteristics, larger absorption bandwidth, and ignorance of the temperature adjustment of the diode. As a result, it is commonly used in LD-pumped solid-state lasers.
However, it has a big discharge cross-section and a brief upper energy lifetime. The power storage capability of Nd: YVO4 is much less than that of Nd: YAG. Not conducive to high power, peak power of the Q – changed pulse result. Their advantages are restricted to continual wave output, high average control, and high conversion effectiveness. Furthermore, the thermal conductivity of Nd: YVO4 is very small, only fifty percent of that of Nd: YAG. Therefore, it is not conducive to accomplishing high-power continuous wave results.
Apply.
Neodymium-doped yttrium vanadate (Nd: YVO4) crystal is a kind of laser crystal with superb efficiency, which is appropriate for making a laser diode pump, particularly a low-power laser. Compared to Nd: YAG, Nd: YVO4 has a greater absorption coefficient as well as a bigger boosted discharge cross-section.
Laser diode-pumped Nd: YVO4 crystals are combined with LBO, BBO, KTP, and other crystals with high nonlinear coefficients. It can accomplish far better frequency-doubling conversion performance. It can output near-infrared, green, and also blue ultraviolet and solid-state lasers.
Nd: YVO4 crystals can be commonly utilized in optical communication, commercial laser handling, laser ranging, semiconductor discovery, information storage space, display screen, laser printing, clinical evaluation, equipment, scientific research study, and other areas.
Moreover, Nd: YVO4 diode-pumped solid-state lasers are swiftly changing conventional water-cooled ion lasers as well as lamp-pumped lasers in the market, specifically in regards to miniaturization as well as single longitudinal mode outcome.
In the 21st century, numerous downstream industries of Nd: YVO4 crystal are growing, and the application variety of Nd: YVO4 crystal is continuously expanding with evident performance advantages.
Growth method.
In the 1960s, Nd: YVO4 crystal was created. It was removed from sodium metavanadate thaw by the air conditioning method. The dimension of the Nd: YVO4 crystal grown by this method was little. Ever since, the development process of Nd: YVO4 crystal has actually been advanced, such as the Zhilar method, fire melting method, floating area development method, Bryman method, and also the pull method. Today, the development techniques of Nd: YVO4 crystal are different. The drawing approach is the mainstream Nd: YVO4 crystal development process, which can expand big, high-quality crystals.
4.1 Pulling method.
Nd3+: YVO4, crystal melting point is really high (concerning 1820 ℃), need to make use of gold-dependent crucible growth, gold-dependent crucible will be oxidized at heat, should utilize a neutral gas (hydrogen) to secure the crucible.
This way, growing in an anoxic environment, the dissolved component will decompose into low-priced vanadium oxide (part of YVO4 will decompose right into YVO3), and oxygen deficiency will certainly take place in the crystal, resulting in the generation of the color center.
Growing in an oxygen-rich ambiance will result in extreme oxidation of the crucible. The minimized episcopes create inclusions inside the crystal. This will bring about strong melt volatilization, leading to the part discrepancy.
By using different growing environments in numerous stages, the oxygen deficiency in the crystal can be supplemented, the volatilization of resources can be inhibited, the single-phase development of the crystal can be ensured, and also the crystal can not be smudged or spread as a result of oxygen shortage because of hypoxia.
