| Transmitting Wavefront Distortion | less than λ/4 @ 633nm | Clear Aperture | >90% central area |
| Chamfer | ≤0.2mm@45degree | Chip | ≤0.1mm |
| Flatness | λ/8 @ 633 nm | Surface Quality | 10/5 S/D |
| Parallelism | better than 10 arc seconds | Perpendicularity | ≤5 arc minutes |
| Angle Tolerance | ≤0.5° | Quality Warranty Period | one year under proper use |
| Typical Coating | AR@1064nm&HT@808nm, HR@1064nm&HT@808nm | Damage Threshold | 700MW/cm^2@1064nm, 10Hz, 10ns |
Physical and Optical Properties:
| Atomic Density | 1.26x1020 atoms /cm3 (Nd1.0%) | Crystal Structure | Zircon Tetragonal, space group D4h-I4/amd a=b=7.1193A,c=6.2892A |
| Density | 4.22g/cm3 | Mohs Hardness | 4-5(Glass-like) |
| Thermal Expansion Coefficient (300K) | αa=4.43x10-6 /K αc=11.37x10-6 /K |
Thermal Conductivity Coefficient (300K) | //C:0.0523W/cm/K ⊥C:0.0510W/cm/K |
| Lasing Wavelength | 1064nm,1342nm | Thermal Optical Coefficient (300K) | dno/dT=8.5×10-6 /K dne/dT=2.9×10-6 /K |
| Stimulated Emission Cross-section | 25×10-19cm2 @ 1064nm | Thermal Optical Coefficient (300K) | dno/dT=8.5×10-6 /K dne/dT=2.9×10-6 /K |
| Stimulated Emission Cross-section | 25×10-19cm2@ 1064nm | Fluorescent Lifetime | 90μs(1% Nd doping) |
| Absorption Coefficient | 31.4cm-1@810nm | Intrinsic Loss | 0.02cm-1@1064nm |
| Gain Bandwidth | 0.96nm@1064nm | Polarized Laser Emission | π polarization; parallel to optic axis(c-axis) |
| Diode Pumped Optical to Optical Efficiency | >60% | Sellemeier equations (λ in μm) | n02=3.77834+0.069736/(λ2-0.04724)-0.010813λ2 ne2=4.59905+0.110534/(λ2-0.04813)-0.012676λ2 |
Laser Properties of Nd:YVO4
1. One of the most attractive character of Nd:YVO4 is, compared with Nd:YAG, it has 5 times larger absorption coefficient in a broader absorption bandwidth around the 808 nm peak pump wavelength, which just matches the standard of high power laser diodes currently available. This means a smaller Nd:YVO4 crystal that could be used for the laser, leading to a more compact laser system. For a given output power, this also means a lower power level at which the laser diode operates, thus extending the lifetime of the expensive laser diode. The broader absorption bandwidth of Nd:YVO4 which may reaches 2.4 to 6.3 times that of Nd:YAG, is also valuable. Besides more efficient pumping, Nd:YVO4 also means a broader range of selection of diode specifications. This will be helpful to laser system makers for wider tolerance and lower cost choice.
2. Nd:YVO4 crystal has larger stimulated emission cross-sections, both at 1064nm and 1342nm. When a-axis cut Nd:YVO4 crystal lasing at 1064m, it is about 4 times higher than that of Nd:YAG, while at 1340nm the stimulated cross-section is 18 times larger, which leads to a CW operation completely outperforming Nd:YAG at 1320nm. These make Nd:YVO4 laser be easy to maintain a strong single line emission at the two wavelengths.
3. Another important character of Nd:YVO4 lasers is, because it is an uniaxial rather than a high symmetry of cubic as Nd:YAG, what it emits is only a linearly polarized, thus avoiding undesired birefringent effects on the frequency conversion. Although the lifetime of Nd:YVO4 is about 2.7 times shorter than that of Nd:YAG, its slope efficiency can be still quite high for a proper design of laser cavity, because of its high pump quantum efficiency.
The major laser properties of Nd:YVO4 vs Nd:YAG are listed in Table below, including stimulated emission cross-sections (σ), Absorption Coefficient (α) Fluorescent lifetime (τ),Absorption Length (La),threshold Power (Pth) and Pump Quantum Efficiency (ηs).
Laser Properties of Nd:YVO4 vs Nd:YAG
| Laser Crystal | Doping (atm%) | σ (x10-19cm2) |
α (cm-1) |
τ (μs) |
Lα (mm) |
Pth (mW) |
ηs (%) |
| Nd:YVO4(a-cut) | 1.0 2.0 |
25 25 |
31.2 72.4 |
90 50 |
0.32 0.14 |
30 78 |
52 48.6 |
| Nd:YVO4(c-cut) | 1.1 | 7 | 9.2 | 90 | 231 | 45.5 | |
| Nd:YAG | 0.85 | 6 | 7.1 | 230 | 1.41 | 115 | 38.6 |
Typical Results of Nd:YVO4
Diode pumped Nd:YVO4 laser output comparing with diode pumped Nd:YAG laser.
| Crystals | Size (mm3) | Pump Power | Output (at 1064nm) |
| Nd:YVO4 | 3x3x1 | 850mW | 350mW |
| Nd:YVO4 | 3x3x5 | 15W | 6W |
| Nd:YAG | 3x3x2 | 850mW | 34mW |
Neodymium doped Gadolinium Vanadate or Nd:YVO4 crystal is one of the most efficient laser host crystal for DPSS lasers. Its large stimulated emission cross-section at lasing wavelength, high absorption coefficient and wide absorption bandwidth at pump wavelength, high damage threshold as well as good physical, optical and mechanical properties make Nd:YVO4 an excellent crystal for high power, stable and cost effective DPSS lasers.
Hangzhou Shalom EO offers the Nd:YVO4 with Nd doping range of 0.1%-3% and with size up to Diam20x20mm.
Application Notes:
Nd:YVO4’s advantages over Nd:YAG
As high as about five times larger absorption efficient over a wide pumping bandwidth around 808nm (therefore, the dependency on pumping wavelength is much lower and a strong tendency to the single mode output).
As large as three times larger stimulated emission cross-section at the lasing wavelength of 1064nm.
Lower lasing threshold and higher slope efficiency.
As a uniaxial crystal with a large birefringence, the emission is only linearly polarized.
