Neodymium Doped Yttrium Orthovanadate (Nd:YVO4)
Nd:YVO4 is the most efficient laser host crystal for diode pumping among the current commercial laser crystals, especially, for low to middle power density. This is mainly for Nd:YVO4's absorption and emission features surpassing Nd:YAG. Pumped by laser diodes, Nd:YVO4 crystal has been incorporated with high NLO coefficient crystals (LBO, BBO or KTP) to frequency-shift the output from the near infrared to green, blue, or even UV. This incorporation to construct all solid state lasers is an ideal laser tool that can cover the most widespread applications of lasers, including machining, material processing, spectroscopy, wafer inspection, light displays, medical diagnostics, laser printing, and data storage, etc. It has been shown that Nd:YVO4 based diode pumped solid state lasers are rapidly occupying the markets traditionally dominated by water-cooled ion lasers and lamp-pumped lasers, especially when compact design and single-longitudinal-mode outputs are required.
Nd:YVO4’s advantages over Nd:YAG
- High absorption efficient over a wide pumping bandwidth around 808 nm
- Large 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 a linearly polarized.
SINO-CRYSTAL Provides Nd:YVO4 as following
- Various doping concentration from 0.1% to 3%
- With quick delivery
- With competitive price
Properties of Nd:YVO4
Atomic Density |
1.26x1020atoms/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 |
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 um) |
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
The Nd:YVO4 crystal has large stimulated emission cross-sections at both 1064nm and 1342nm. The stimulated emission cross-section of an a-axis cut Nd:YVO4 crystal at 1064nm is about 4 times higher than that of the Nd:YAG crystal. Although the lifetime of Nd:YVO4 is about 2.7 times shorter than that of Nd:YAG. Because of its high pump quantum efficiency, the slope efficiency of Nd:YVO4 can be very high if the laser cavity is properly designed. Table 1 lists the major laser properties of Nd:YVO4 in comparison with those of Nd:YAG.
Laser Properties of Nd:YVO4 and 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 |
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 |
Nd:YVO4 Specifications
·Dimension tolerance:(W±0.1)x(H±0.1)x(L+0.5/-0.1)mm
·Transmitting wave-front distortion: less than λ/4 @ 633nm
·Clear aperture:>90% central area
·Chamfer: ≤0.2mm@45
·Chip: ≤0.1mm
·Flatness: λ/8 @ 633 nm (L≥2.5mm), λ/4 @ 633nm (L<2.5mm)
·Scratch/Dig code: 10/5 to MIL-PRF-13830B
·Parallelism: better than 20 arc seconds
·Perpendicularity: ≤5 arc minutes
·Angle tolerance:≤0.5°
·Damage threshold: >1 GW/cm2 @1064nm, TEM00, 10ns, 10Hz (AR-coated)
·Quality Warranty Period: one year under proper use.
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