Nd:YVO4  Crystal

Nd:YVO4 (Neodymium doped yttrium vanadate) Crystal is a kind of crystal with excellent performance, which is suitable for manufacturing laser diode pumping, especially for low and medium power lasers. Now lasers have been widely used in many fields such as Machinery, Material Processing, Spectroscopy, Crystals inspection, Display, Medical Inspection, Laser Printing, Data Storage and so on.

  • As high as about five times larger absorption efficient over a wide pumping bandwidth around 808nm.
  • As large as three times larger stimulated emission cross-section at the leasing wavelength of 1064nm.
  • Lower lasing threshold and higher slope efficiency
  • As a uniaxial crystal with a large birefringence, the emission is a linearly polarized.
  • Due to the wider pumping bandwidth of Nd:YVO4, its laser performance can better adapt to the temperature change of LD.
  • Due to the large cross-section of absorption, the attraction coefficient is large, and due to the small thermal conductivity, Nd:YAG is suitable for the thin-scale pumping of medium and low power lasers.

Nd:YVO4

Overview of NdYVO4 Crystal

NdYVO4 crystal is a crystalline material formed by adding neodymium ions to yttrium orthovanadate. It is commonly used as an active laser medium for diode-pumped solid-state lasers. It comes as a transparent blue-tinted material. It has high optical gain, high thermal conductivity, and low lasing threshold. 

Key Specifications

wdt_ID Attributes Values
1 Dopant 0.1% ~ 3%
2 Orientation A-CUT +/-0.5°
3 Size&Tolerance W(+/-0.1)*H(+/-0.1)*L(+0.5/-0.1)mm
5 Surface quality better than 10/5(MIL-PRF-13830B)
6 Perpendicularity ≤5′
7 Parallelism ≤10″
8 Bevel <0.2mmx45°
9 Flatness λ/10@633nm
10 Chips <0.1mm
11 Coating AR@1064(R<0.2%)
AR@1064(R<0.2%)&532(R<0.5%)
AR@1064(R<0.2%)&808(R<0.5%)
HR@1064(R>99.5%)&808(R>99.0%)
AR@1064(R<0.2%)&532(R<0.5%)&808(R<3%)
12 Damage Threshold 1GW/cm² 10ns 10Hz at 1064nm

Characteristic of NdYVO4 Crystal

NdYVO4 (neodymium-doped yttrium orthovanadate) crystals are a type of laser gain medium with unique properties that make them useful in a variety of laser applications. Some of the key specifications of NdYVO4 crystals include:

  1. Crystal structure: NdYVO4 crystals have a tetragonal crystal structure with lattice parameters of a=b=7.12 Å and c=6.29 Å.
  2. Dopant concentration: NdYVO4 crystals are doped with neodymium (Nd3+) ions, typically at concentrations ranging from 1% to 3%.
  3. Absorption and emission spectra: NdYVO4 crystals have strong absorption in the range of 750-810 nm, and emission peaks at 1064 nm and 1342 nm.
  4. Laser wavelength: NdYVO4 crystals are used as the gain medium in lasers that emit at 1064 nm and 1342 nm, which are commonly used for industrial and medical applications.
  5. Thermal conductivity: NdYVO4 crystals have high thermal conductivity, which allows them to dissipate heat efficiently and operate at high power levels.
  6. Nonlinear optical properties: NdYVO4 crystals exhibit strong nonlinear optical properties, such as second harmonic generation (SHG) and sum frequency generation (SFG), which make them useful in frequency doubling and mixing applications.
  7. Damage threshold: NdYVO4 crystals have high damage thresholds, which allow them to withstand high laser intensities without being damaged.

Products & Property

Comparing NdYVO4 and NdYAG

Nd:YVO4 has a higher pump absorption and gain than Nd:YAG, as well as a broader gain bandwidth and wavelength range for pumping. It also allows for higher repetition rates and shorter pulse durations, is more efficient and forgiving in terms of pump spectrum and temperature stability, and has a larger output power than Nd:YAG.

Property Nd:YVO4 Nd:YAG
Atomic density (atoms/cm3) 1.37×10^20 1.38×10^20
Crystal structure Zircon tetragonal Cubic
Density (g/cm3) 4.22 4.56
Thermal expansion coefficient (10^-6/K) 4.43 (a-axis), 11.37 (c-axis) 7.8
Lasing wavelengths (nm) 914, 1064, 1342 1064, 1320, 1444
Fluorescence lifetime (μs) at 1% doping 90 230
Absorption cross-section at 808 nm (10^-20 cm2) 5.5 0.8
Emission cross-section at 1064 nm (10^-19 cm2) 3.0 1.3
Polarized laser emission π-polarization; parallel to c-axis Random

Advantage of Nd:YVO4

Some of the advantages of Nd:YVO4 over Nd:YAG are:

  • Nd:YVO4 has a higher optical gain, which means it can amplify the laser light more efficiently.
  • Nd:YVO4 has a lower lasing threshold, which means it can start lasing with less pump power.
  • Nd:YVO4 has a wider absorption bandwidth around 808 nm, which means it can absorb more pump light from a diode laser and is less sensitive to temperature changes.
  • Nd:YVO4 has a linearly polarized emission, which means it can produce a more stable and pure laser beam.
  • Nd:YVO4 has multiple lasing wavelengths, such as 914 nm, 1064 nm, and 1342 nm, which can be used for different applications or frequency doubling.

However, Nd:YVO4 also has some disadvantages compared to Nd:YAG, such as:

  • Nd:YVO4 has a lower thermal conductivity, which means it can heat up more easily and cause thermal effects such as lensing or distortion.
  • Nd:YVO4 has a shorter fluorescence lifetime, which means it can store less energy and is more prone to saturation.

Nd:YVO4 has a strong polarization dependence, which means it requires careful alignment of the pump and laser beams.

A-Cut and C-Cut of NdYVO4

A-cut and c-cut of Nd:YVO4 refer to the orientation of the crystal with respect to the crystallographic axes. A-cut means that the crystal is cut perpendicular to the a-axis, and c-cut means that the crystal is cut perpendicular to the c-axis. The choice of crystal cut affects the polarization, gain, and thermal properties of the Nd:YVO4 laser.

Nd:YAG does not need to concern about a-cut and c-cut, because it has a cubic crystal structure and is isotropic. The polarization of Nd:YAG laser is usually controlled by a Brewster plate or other external elements.

Polarization Output of NdYVO4

Nd:YAG does not have polarized laser emission, because it has a cubic crystal structure and is isotropic. Nd:YVO4 has polarized laser emission, because it has a zircon tetragonal crystal structure and is birefringent. The polarization orientation of Nd:YVO4 depends on the crystal cut and the pump beam alignment. The highest gain is usually achieved for π-polarization, which is parallel to the c-axis of the crystal.

Bonding Crystal with NdYVO4

One type of crystal that can be bonded with Nd:YVO4 is YVO4, which is the host crystal of Nd:YVO4. The bonding of Nd:YVO4 and YVO4 can be done by a diffusion bonding method, which involves heating and pressing the crystals together without any adhesive materials. The function of the YVO4 endcap is to reduce the thermal effects at high power, such as thermal lensing, thermal stress, and thermal fracture. The YVO4 endcap can also protect the Nd:YVO4 crystal from damage by the pump beam or the environment.

Another type of crystal that can be bonded with Nd:YVO4 is Nd:GdVO4, which is another neodymium-doped vanadate crystal with similar properties to Nd:YVO4. The bonding of Nd:YVO4 and Nd:GdVO4 can also be done by a diffusion bonding method. The function of the Nd:GdVO4 crystal is to generate a dual-spectral-band laser around 1.06 μm in Q-switched and mode-locked operations. The Nd:GdVO4 crystal can provide a broader gain bandwidth and a higher emission cross-section than Nd:YVO4 at 1.06 μm.

Common Doping concentration and length & diameter of NdYVO4 crystal

One type of crystal that can be bonded with Nd:YVO4 is YVO4, which is the host crystal of Nd:YVO4. The bonding of Nd:YVO4 and YVO4 can be done by a diffusion bonding method, which involves heating and pressing the crystals together without any adhesive materials. The function of the YVO4 endcap is to reduce the thermal effects at high power, such as thermal lensing, thermal stress, and thermal fracture. The YVO4 endcap can also protect the Nd:YVO4 crystal from damage by the pump beam or the environment.

Another type of crystal that can be bonded with Nd:YVO4 is Nd:GdVO4, which is another neodymium-doped vanadate crystal with similar properties to Nd:YVO4. The bonding of Nd:YVO4 and Nd:GdVO4 can also be done by a diffusion bonding method. The function of the Nd:GdVO4 crystal is to generate a dual-spectral-band laser around 1.06 μm in Q-switched and mode-locked operations. The Nd:GdVO4 crystal can provide a broader gain bandwidth and a higher emission cross-section than Nd:YVO4 at 1.06 μm.