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Introduction
The Czochralski method Gadolinium Vanadate
doped with neodymium, Nd:GdVO4, is a promising material
for diode pumped lasers. Like neodymium doped yttrium vanadate,
the gadolinium vanadate  exhibits a larger absorption and emission cross
section compared to Nd:YAG. In fact, Nd:GdVO4 has a 7-times
higher absorption cross section at 808nm and a 3-times larger
emission cross section at 1.06µm than does Nd:YAG. Nd:GdVO44
has the additional advantage over Nd:YVO4 of a much higher
thermal conductivity.
In each case of cw laser performance at 1.06µm
and 1.34µm and intracavity doubling with KTP and LBO, the
gadolinium vanadate had a higher slope efficiency or optical
conversion efficiency than did yttrium vanadate.
Basic Properties:
|
Chemical
Formula |
Gd.99Nd.01VO4 |
|
Dopant
Concentration Nd3+, at.% |
1.0¡À
0.1 |
|
Crystal
Structure |
Zircon
Tetragonal, space group D4h-I4/amd
a=b=7.212, c=6.350 |
|
Space
Group |
I41/amd |
Optical Properties:
|
Lasing
Transition |
4F3/2
¨C4I11/2 |
|
Lasing
Wavelength, nm |
1062.9 |
|
Emission
Cross Section,
(E ½
½
c, at
1064 nm) cm2: |
7.6x10-19 |
|
Absorption
Cross Section,
(E ½
½
c,
at 808 nm) cm2: |
4.9x10-19 |
|
Density:
|
5.48g/cm3
|
|
Mohs
hardness: |
4.6-5
|
| Linewidth:
|
3
nm
|
|
Relaxation
Time of Terminal Lasing Level: |
100ms
|
|
Absorption
Coefficient, (E
½
½
c, at 808 nm) cm-1 |
74 |
|
Thermal
Conductivity, W/(mxK): <110> |
11.7 |
|
Density,
g/cm3 |
5.47 |
Index
of Refraction (at 1064 nm):
| Wave
length |
500 |
630 |
850
|
1064 |
1300 |
1400 |
1550 |
| no |
2.0488 |
2.01685 |
1.99490 |
1.98535 |
1.97889 |
1.97683 |
1.97410 |
| ne |
2.31219 |
2.25431 |
2.21482 |
2.19813 |
2.18742 |
2.18419 |
2.18009 |
Demonstrated
Performance in Diode Pumped Laser Systems
|
Laser Operation |
Output
wavelength (µm)
|
Frequency
Doubler
|
Slope Efficiency
(%)
|
Max. Optical
Conversion Efficiency (%)
|
|
cw
|
1.06
|
none
|
42.9
|
38.1
|
|
cw
|
1.34
|
none
|
40.2
|
n/a
|
|
cw
|
0.53
|
KTP
|
n/a
|
21.0
|
|
cw
|
0.67
|
LBO
|
n/a
|
2.8
|
|
Q-switched
|
1.06
|
none
|
31.6
|
n/a
|
|
Q-switched
|
0.53
|
KTP
|
n/a
|
25.0
|
Information
Regarding Neodymium Laser Host Crystals
|
|
Nd:YVO4
|
Nd:GdVO4
|
Nd:YAG
|
|
Laser wavelengths |
1064.3nm
1342.0 nm |
1062.9 nm
~1340 nm |
1064.2 nm
1338.2 nm
|
|
Emission bandwidth
(linewidth at 1064 nm)
|
0.8 nm
|
No data
|
0.45 nm
|
|
Effective laser cross section
(emission cross section at 1064 nm)
|
15.6 x 10-19 cm-2
|
7.6 x 10-19cm-2
|
6.5 x 10-19 cm-2
|
|
Polarization
|
Parallel to c-axis
|
Parallel to c-axis
|
unpolarized
|
|
Radioactive lifetime (microseconds)
at 1% Nd doping
|
~ 100 µs
|
~ 95 µs
|
230 µs
|
|
Pump wavelength |
808.5 nm
|
808.4 nm
|
807.5 nm
|
|
Peak pump absorption at 1%
doping |
~ 41 cm-1
|
~ 57 cm-1
|
|
|
Thermal conductivity, W/mK
|
5.1
|
11.7(Ref. 7)
|
14
|
Material
Properties: Comparing Nd:GdVO4 and Nd:YVO4
|
|
Nd:GdVO4
|
Nd:YVO4 |
| Crystal Structure, Space Group
|
Tetragonal, I41/amd |
Tetragonal, I41/amd
|
| Lattice constants, nm
|
a:0.721
b:0.635
|
a:0.721
b:0.629
|
| Melting temperature, ¡ãC
|
1780
|
1825
|
| Thermal expansion @25¡ãC, x10-6/¡ãC |
a |
1.5 |
a |
4.43 |
| b |
7.3 |
b |
11.4 |
| Specific heat @25¡ãC, cal/mol
K
|
32.6 |
24.6 |
| dn / dT, x10-6 /¡ãC
|
4.7 |
2.7 |
Nd:GdVO4 Specifications:
|
Nd:
Dopant Level |
1.0
atm% , 0.5% |
|
Wavefront
Distortion |
<
l/8
at 633 nm |
|
Scattering
Sites |
invisible,
probed with a He-Ne laser |
|
Orientation |
+/-0.5¡ã |
|
Dimensional
Tolerance |
+0.1/-0.1 |
|
Surface
quality |
10/5
Scratch/Dig per MIL-O-13830B |
|
Flatness |
l/10
at 633 nm |
|
Clear
Aperture |
>
Central 90% |
|
Parallelism |
<
10 arc sec. |
R/AR Coating:S1:
HR@1064&532nm HT@808nm S2:
AR@1064&532nm
AR/AR Coating: S1:
AR@1064nm&532nm HT@808nm S2:
AR@1064&532nm
Nd:GdVO4
long rods
Standard Products
| Part No. |
Crystals |
Doping |
Dimension |
Coating |
| GDV01 |
Nd:GdVO4 |
0.2-1% |
f3X30-65mm |
AR/AR@1064nm |
| GDV02 |
Nd:GdVO4 |
0.2-1% |
f4X30-65mm |
AR/AR@1064nm |
Note:
The Tm:GdVO4 or Ho:GdVO4 are available from our company.
 
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Laser Crystals