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Introduction
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 (KTP,BBO,or BIBO ) 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.
  Low lasing
threshold and high slope efficiency
Large stimulated emission cross-section at lasing
wavelength
High absorption over a wide pumping wavelength bandwidth
Optically uniaxial and large birefringence emits polarized
laser
Low dependency on pumping wavelength and tend to single
mode output
CRYSTECH massively
produces and provides high quality Nd:YVO4 crystals at competitive
prices.
Basic Properties:
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Atomic
Density:
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1.26x1020
atoms/cm3 (Nd 1.0%)
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Crystal
Structure:
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Zircon
Tetragonal, space group D4h-I4/amd
a=b=7.1193, c=6.2892
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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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a a=4.43x10-6/K
a c=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): |
dno/dT=8.5x
10-6/K
dne/dT=2.9x 10-6/K
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Sellmeier
Equation
(for pure YVO4 crystals):
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no2=3.77834+0.069736/(l2-0.04724)-0.0108133.l2
ne2=4.59905+0.110534/(l2-0.04813)-0.0122676.l2
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Stimulated
emission cross-section:
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25x
10-19cm2
@1064nm
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Fluorescent
lifetime:
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90m s
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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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p 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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Laser Properties:
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.
Table 1. Laser
Properties of Nd:YVO4
| Laser
crystal
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Doping(atm%)
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s(x10-19cm2)
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a
(cm-1)
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t
(ms)
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la
(mm)
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Pth(mW)
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η
s(%)
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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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Note: stimulated emission cross-sections (σ), Absorption Coefficient (α), Fluorescent lifetime (τ),Absorption Length (La),threshold Power (Pth) , Pump Quantum Efficiency (ηs).
Diode pumped Nd:YVO4 laser output comparing
with diode pumped Nd:YAG laser.
| Crystals
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Size
(mm3) |
Pump
Power |
Output
(at 1064nm) |
| 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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Nd YVO4's
Specification:
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Nd:
Dopant Level
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0.1
- 3.0 atm%
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Wavefront
Distortion
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<
l/8
at 633 nm
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Scattering
Sites
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invisible,
probed with a He-Ne laser
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Orientation
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±0.5deg.
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Dimensional
Tolerance
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±0.1mm
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End-faces
Configuration
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Plano/Plano
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Surface
quality
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10/5
Scratch/Dig per MIL-O-13830B
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Flatness
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l/10
at 633 nm
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Clear
Aperture
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>
Central 90%
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Parallelism
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<
10 arc sec.
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Intrinsic
Loss
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<
0.1% cm-1
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Standard Products
| Part
No. |
Doping |
Dimension
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Coating |
| NYV2301 |
2% |
3x3x1mm |
HR/AR
Coating |
| NYV2302 |
2% |
3x3x1mm |
AR/AR
Coating |
| NYV1301 |
1% |
3x3x1mm |
HR/AR
Coating |
| NYV1305 |
1% |
3x3x5mm |
AR/AR
Coating |
| NYV5310 |
0.5% |
3x3x10mm |
AR/AR
Coating |
| NYV7408 |
0.27% |
4x4x8mm |
AR/AR Coating |
AR/AR:
S1:AR@1064(R<0.1%)&532nm(R<0.5%) HT@808nm(R<5%);
S2:AR@1064&532nm
HR/AR: S1:HR@1064(R>99.8%)&532nm(R>99%)
HT@808nm(R<5%);
S2:AR@1064&532nm
Note: Other
specifications of Nd:YVO4 crystals and coatings
are also available upon request.
Coating:
S1:
R>99.8% @1064&532nm, R<5% @808 nm;S2: R>99.8%
@1064 nm, R<5% @532 nm
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Laser Crystals