Laser Properties of Nd:YVO4
1. One most attractive character of Nd:YVO4 is, compared with Nd:YAG,
its 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. 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 for 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, it only emits a linearly polarized
laser, 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).
Laser Properties of Nd:YVO4 vs Nd:YAG
|
LASER CRYSTAL |
DOPING
(atm%) |
σ
(x10-19 CM2) |
α
(cm-1) |
τ
(μs) |
La
(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
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 |
Diode pumped Nd:YVO4+KTP green laser.
8W green laser was generated from a 15W LD pumped 0.5%Nd:YVO4 with intracavity KTP.
200mW green outputs are generated from 1 W LD pumped 2%Nd:YVO4 lasers by using Banner Union’s
2x2x5mm KTP and 3x3x1mm Nd:YVO4.
2-5mw green outputs are generated from 180mw LD pumped 3%Nd:YVO4 and KTP glued crystals.
For more details, please refer to Glued Crystals.
Coating Service
◇ Both ends AR/AR-1064/808nm, R<0.2%@1064nm,R<2%@808nm
◇ S1:HR@1064&532 nm,HT808 nm,
R>99.8%@1064&532nm,T>90%@808nm
S2:AR@1064&532 nm, R<0.2%@1064nm,R<0.5%@532nm
◇ S1:HR@1064,HT808, R>99.8%@1064nm,T>95%@808nm
S2:AR@1064, R<0.1%@1064nm.
◇ S1,S2 AR-coated, S3:gold/chrome plated.
◇ Both ends AR/AR-1064 nm; S3:AR-808 nm
◇ Other coatings are available upon request. |
Prisms
