Neodymium Doped Yttrium Orthovanadate (Nd:YVO4)
Nd:YVO4's advantages
l As high as about five times larger absorption efficient over a wide pumping bandwidth around 808 nm (therefore, the dependency on pumping wavelength is much lower and a strong tendency to the single mode soutput)
l As large as three times larger stimulated emission cross-section at the lasing wavelength of 1064nm
l Lower lasing threshold and higher slope efficiency
l As a uniaxial crystal with a large birefringence, the emission is only a linearly polarized.
Caston Provides:
l Various doping concentration from 0.1% to 3%
l Various size bulk and finished high quality Nd:YVO4 crystals up to Φ35x50mm3 and Φ20x20mm3, respectively;
l With quick delivery
l With competitive price
Basic Properties:
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Atomic Density:
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1.26x1020 atoms/cm3 (Nd1.0%)
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Crystal Structure:
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Zircon Tetragonal, space group D4h-I4/amd
a=b=7.1193A,c=6.2892A
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Density;
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4.22g/cm3
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Mohs Hardness:
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4-5(Glass-like)
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Thermal Expansion Coefficient(300K):
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αa=4.43x10-6/K
αc=11.37x10-6/K
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Thermal Conductivity Coefficient(300K):
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//C:0.0523W/cm/K
⊥C:0.0510W/cm/K
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Optical Properties:
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Lasing wavelength:
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1064nm,1342nm,914nm
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Thermal optical coefficient (300K):
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dno/dT=8.5×10-6/K
dne/dT=2.9×10-6/K
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Stimulated emission cross-section:
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25×10-19cm2 @ 1064nm
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Fluorescent lifetime:
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90μs
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Absorption coefficient:
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31.4cm-1 @810nm
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Intrinsic loss:
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0.02cm-1 @1064nm
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Gain bandwidth:
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0.96nm@1064nm
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Polarized laser emission:
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π polarization; parallel to optic axis(c-axis)
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Diode pumped optical to optical efficiency:
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>60%
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Sellemeier equations
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n02=3.77834+0.069736/(λ2-0.04724)-0.010813λ2
ne2=4.59905+0.110534/(λ2-0.04813)-0.012676λ2
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Laser Properties of Nd:YVO4 vs Nd:YAG
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 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, it 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 (η).As the common and commercial choice of electro-optic crystal used for high average power TFM applications, BBO has significant advantages over other crystals such as LiNbO3 and KTP. The wide transparency range (from 200nm to 3000nm) of BBO allows it to be used in diverse applications.
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LASER CRYSTAL
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DOPING(ATM%)
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σ
(x10-19CM2)
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α
(CM-1)
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τ
(MS)
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Lα
(MM)
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PTH
(MW)
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ηs
(%)
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Nd:YVO4(a-cut)
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1.0
2.0
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25
25
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31.2
72.4
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90
50
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0.32
0.14
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30
78
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52
48.6
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Nd:YVO4(c-cut)
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1.1
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7
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9.2
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90
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231
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45.5
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Nd:YAG
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0.85
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6
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7.1
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230
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1.41
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115
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38.6
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Typical Results:
Diode pumped Nd:YVO4 laser output comparing with diode pumped Nd:YAG laser.
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Crystals
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Size(mm3)
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Pump Power
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Output (at 1064nm)
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Nd:YVO4
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3x3x1
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850mW
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350mW
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Nd:YVO4
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3x3x5
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15W
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6W
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Nd:YAG
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3x3x2
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850mW
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34mW
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Warranty on Nd:YVO4 Specifications from Caston:
• Transmitting wavefront distortion:less than λ/4 @ 633nm
• Dimension tolerance:(W±0.1mm)x(H±0.1mm)x(L+0.2mm/-0.1)
• Clear aperture:>90% central area
• Flatness: λ/8 @ 633 nm, and λ/4 @ 633nm for thickness less than 2mm
• Scratch/Dig code: 10/5 to MIL-O-13830A
• Parallelism:better than 20 arc seconds
• Perpendicularity: 5 arc minutes
• Angle tolerance:<±0.5°
• AR coating:R<0.2% at 1064nm
• Quality Warranty Period:one year under proper use
TEL:+86-591-83995661
