Nd: YVO4 crystal

Nd: YVO4 crystal belongs to the tetragonal system, positive uniaxial crystal. Nd: YVO4 crystal has been widely acknowledged as an important laser product considering its growth in 1966.

Nevertheless, the scientists found defects in the scattering centre, absorption colour centre, and so on. It is, as a result, impossible to grow top-quality crystals of the dimension required for a flash pump.

Luckily, it has excellent absorption and gains to diode radiation’s wavelength. And the transmission section is substantial. The outcome laser has good polarization qualities. These suffice to cover the shortcomings of its small growth size.

Advantages

Nd: YVO4 crystal has superb properties. Compared with another generally used Nd: YAG crystal (neodymium-doped yttrium aluminium garnet crystal), its pump broadband is more substantial. The absorption bandwidth effectiveness is greater. The promoted emission cross-section is more thorough and has outstanding growth value. Nd: YVO4 crystals are used with nonlinear optical crystals such as LBO crystals, BBO crystals, KTP crystals, etc. It can recognize frequency-doubling conversion and adjust functioning wavelength. The all-solid-state laser constructed from Nd: YVO4 crystal can output near-infrared, green, blue, ultraviolet, and so forth.

• Concerning 808 nm pump data transfer, concerning the Nd: YAG five times
• The area at 1064 nm of the promoted radiation discharge is an Nd: YAG 3 times.
• Light damages limit is low, high incline efficiency
• Uniaxial crystal axis, the output of linear polarization

Weaknesses

Compared with the typical Nd: YAG crystal, Nd: YVO4 has the advantages of a much more significant absorption coefficient, higher emission sample, polarization absorption and discharge characteristics, larger absorption transmission capacity, and insensitivity to the temperature change of the diode. Consequently, it is commonly made use of LD-pumped solid-state lasers.

Nevertheless, it has a big discharge cross-section and a short upper energy lifetime. The power storage space capacity of Nd: YVO4 is a lot less than that of Nd: YAG. The peak power of the Q – changed pulse outcome is not for high energy. Their benefits are restricted to continuous wave output, high ordinary control, and high conversion efficiency. Furthermore, the thermal conductivity of Nd: YVO4 is extremely little, only half that of Nd: YAG. Therefore, it is not for achieving high-power constant wave outcomes.

Apply

Neodymium-doped yttrium vanadate (Nd: YVO4) crystal is a type of laser crystal with excellent performance, which is suitable for producing a laser diode pump, particularly a low-power laser. Compared with Nd: YAG, Nd: YVO4 has a greater absorption coefficient, and larger stimulated exhaust cross-section.

Laser diode-pumped Nd: YVO4 crystals are combined with LBO, BBO, KTP and other crystals with high nonlinear coefficients. It can achieve much better frequency-doubling conversion efficiency. It can result in near-infrared, green, and blue ultraviolet and solid-state lasers.

Nd: YVO4 crystals can be widely used in optical interaction, commercial laser processing, laser varying, semiconductor detection, information storage space, display, laser printing, clinical inspection, equipment, scientific study, and other fields.

Moreover, Nd: YVO4 diode-pumped solid-state lasers are swiftly replacing typical water-cooled and lamp-pumped ion lasers, especially regarding miniaturization and single longitudinal mode output.

In the 21st century, many downstream sectors of Nd: YVO4 crystal are expanding, and the application series of Nd: YVO4 crystal is frequently increasing with noticeable efficiency advantages.

Growth method

In the 1960s, Nd: YVO4 crystal was created. It was removed from sodium metavanadate thaw by the air conditioning approach. The dimension of the Nd: YVO4 crystal expanded by this approach was little. Ever since, the growth process of Nd: YVO4 crystal has been put forward, such as the Zhilar method, fire melting method, floating area growth method, Bryman method and pull method. Currently, the growth approaches of Nd: YVO4 crystal are numerous. The illustration method is the mainstream Nd: YVO4 crystal growth procedure, which can grow large, top-notch crystals.

4.1 Pulling method.

Nd3+: YVO4, crystal melting point is really high (concerning 1820 ℃), need to use gold-dependent crucible growth, gold-dependent crucible will certainly be oxidized at high temperature, have to make use of a neutral gas (hydrogen) to safeguard the crucible.

By doing this, growing in an anoxic environment, the dissolved part will decompose into low-priced vanadium oxide (part of YVO4 will disintegrate right into YVO3), and oxygen deficiency will certainly happen in the crystal, leading to the generation of the colour centre.

Growing in an oxygen-rich environment will certainly lead to extreme oxidation of the crucible. The decreased episcopes form incorporations inside the crystal. This will certainly cause strong melt volatilization, leading to component variance.

By utilizing different expanding environments in different stages, the oxygen deficiency in the crystal can be supplemented, the volatilization of raw materials can be inhibited, the single-phase growth of the crystal can be assured, and the crystal can not be blackened or scattered because of oxygen shortage because of hypoxia.